• Elasitcsearch High Level Rest Client使用示例


    一、ES Client 简介

    1. ES是一个服务,采用C/S结构

    2. 回顾 ES的架构

     

    3. ES支持的客户端连接方式

    3.1 REST API ,端口 9200

      这种连接方式对应于架构图中的RESTful style API这一层,这种客户端的连接方式是RESTful风格的,使用http的方式进行连接

    3.2 Transport 连接 端口 9300

          这种连接方式对应于架构图中的Transport这一层,这种客户端连接方式是直接连接ES的节点,使用TCP的方式进行连接

    4. ES提供了多种编程语言客户端

     

    官网可以了解详情:

    https://www.elastic.co/guide/en/elasticsearch/client/index.html

    二、Java REST Client介绍

    1. ES提供了两个JAVA REST client 版本

    Java Low Level REST Client: 低级别的REST客户端,通过http与集群交互,用户需自己编组请求JSON串,及解析响应JSON串。兼容所有ES版本
    Java High Level REST Client: 高级别的REST客户端,基于低级别的REST客户端,增加了编组请求JSON串、解析响应JSON串等相关api。使用的版本需要保持和ES服务端的版本一致,否则会有版本问题。

    2. Java Low Level REST Client 说明

    特点,maven 引入、使用介绍: https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-low.html

    API doc :https://artifacts.elastic.co/javadoc/org/elasticsearch/client/elasticsearch-rest-client/6.2.4/index.html.

    3. Java High Level REST Client 说明

    从6.0.0开始加入的,目的是以java面向对象的方式来进行请求、响应处理。
    每个API 支持 同步/异步 两种方式,同步方法直接返回一个结果对象。异步的方法以async为后缀,通过listener参数来通知结果
    高级java REST 客户端依赖Elasticsearch core project

    兼容性说明:

    依赖 java1.8 和 Elasticsearch core project
    请使用与服务端ES版本一致的客户端版本

    4. Java High Level REST Client  maven 集成

    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>elasticsearch-rest-high-level-client</artifactId>
        <version>6.2.4</version>
    </dependency>

    5. Java High Level REST Client  初始化

    RestHighLevelClient client = new RestHighLevelClient(
            RestClient.builder(
                    new HttpHost("localhost", 9200, "http"),
                    new HttpHost("localhost", 9201, "http")));

    创建client

    final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
    credentialsProvider.setCredentials(AuthScope.ANY,
            //es账号密码
            new UsernamePasswordCredentials(ES_USER_NAME, ES_PWD));
    try {
        client = new RestHighLevelClient(
                //传入RestClientBuilder
                RestClient.builder(
                        new HttpHost(host, port)
                ).setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
                    public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) {
                        //这里可以设置一些参数,比如cookie存储、代理等等
                        httpClientBuilder.disableAuthCaching();
                        return httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
                    }
                }).setMaxRetryTimeoutMillis(2000)
        );
    }catch (Exception e)
    {
        //示例方法,不处理异常
        e.printStackTrace();
    }

     ===================

    import org.apache.http.HttpHost;
    import org.elasticsearch.client.RestClient;
    import org.elasticsearch.client.RestClientBuilder;
    import org.elasticsearch.client.RestHighLevelClient;
     
    /**
     * @author xiefg
     * @create 2018-01-05 14:10
     * @desc
     **/
    public class RestClientFactory {
        private static  String HOST="192.168.170.69";
        private static  int PORT = 9200;
        private static final String SCHEMA = "http";
        private static final int CONNECT_TIME_OUT = 1000;
        private static final int SOCKET_TIME_OUT = 30000;
        private static final int CONNECTION_REQUEST_TIME_OUT = 500;
     
        private static final int MAX_CONNECT_NUM = 100;
        private static final int MAX_CONNECT_PER_ROUTE = 100;
     
        private static HttpHost HTTP_HOST=null;
        private static boolean uniqueConnectTimeConfig = false;
        private static boolean uniqueConnectNumConfig = true;
        private static RestClientBuilder builder;
        private static RestClient restClient;
        private static RestHighLevelClient restHighLevelClient;
     
        public static void init(){
           // HOST = Configuration.getProperty("esHost");
           // PORT = Integer.parseInt(Configuration.getProperty("esPort"));
            if(HTTP_HOST==null){
                HTTP_HOST=new HttpHost(HOST,PORT,SCHEMA);
            }
            builder = RestClient.builder(HTTP_HOST);
            if(uniqueConnectTimeConfig){
                setConnectTimeOutConfig();
            }
            if(uniqueConnectNumConfig){
                setMutiConnectConfig();
            }
            restClient = builder.build();
            restHighLevelClient = new RestHighLevelClient(builder);
        }
     
        /**
         *     主要关于异步httpclient的连接延时配置
         */
     
        public static void setConnectTimeOutConfig(){
            builder.setRequestConfigCallback(requestConfigBuilder -> {
                requestConfigBuilder.setConnectTimeout(CONNECT_TIME_OUT);
                requestConfigBuilder.setSocketTimeout(SOCKET_TIME_OUT);
                requestConfigBuilder.setConnectionRequestTimeout(CONNECTION_REQUEST_TIME_OUT);
                return requestConfigBuilder;
            });
        }
        /**
         *    主要关于异步httpclient的连接数配置
         */
        public static void setMutiConnectConfig(){
            builder.setHttpClientConfigCallback(httpClientBuilder -> {
                httpClientBuilder.setMaxConnTotal(MAX_CONNECT_NUM);
                httpClientBuilder.setMaxConnPerRoute(MAX_CONNECT_PER_ROUTE);
                return httpClientBuilder;
            });
        }
     
        public static RestClient getClient(){
            return restClient;
        }
     
        public static RestHighLevelClient getHighLevelClient(){
            if(restHighLevelClient==null){
                init();
            }
            return restHighLevelClient;
        }
     
        public static void close() {
            if (restHighLevelClient != null) {
                try {
                    restHighLevelClient.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }
     

    给定集群的多个节点地址,将客户端负载均衡地向这个节点地址集发请求

    Client 不再使用了,记得关闭它:

    client.close();

     API及用法示例,请参考:

    https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-supported-apis.html

    三、Java High Level REST Client  使用示例

    准备:

    编写示例之前首先在maven工程里面引入和ES服务端版本一样的Java客户端

        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>6.2.4</version>
         </dependency>

    给定集群的多个节点地址,将客户端负载均衡地向这个节点地址集发请求:

    InitDemo.java

    package com.study.es_hrset_client;
    
    import org.apache.http.HttpHost;
    import org.elasticsearch.client.RestClient;
    import org.elasticsearch.client.RestHighLevelClient;
    
    /**
     * 
     * @Description: 获取Java High Level REST Client客户端
     * @author lgs
     * @date 2018年6月23日
     *
     */
    public class InitDemo {
    
        public static RestHighLevelClient getClient() {
    
            RestHighLevelClient client = new RestHighLevelClient(
                    RestClient.builder(new HttpHost("localhost", 9200, "http"),
                            new HttpHost("localhost", 9201, "http")));
    
            return client;
        }
    }

    注意使用ES的客户端时类比之前我们在Kibana进行的ES的相关操作,这样使用起来更加有效果

    1. Create index 创建索引

    CreateIndexDemo.java

    package com.study.es_hrset_client;
    
    import java.io.IOException;
    
    import org.elasticsearch.action.admin.indices.alias.Alias;
    import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
    import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
    import org.elasticsearch.client.RestHighLevelClient;
    import org.elasticsearch.common.settings.Settings;
    import org.elasticsearch.common.xcontent.XContentType;
    
    /**
     * 
     * @Description: 创建索引
     * @author lgs
     * @date 2018年6月23日
     *
     */
    public class CreateIndexDemo {
    
        public static void main(String[] args) {
            try (RestHighLevelClient client = InitDemo.getClient();) {
    
                // 1、创建 创建索引request 参数:索引名mess
                CreateIndexRequest request = new CreateIndexRequest("mess");
    
                // 2、设置索引的settings
                request.settings(Settings.builder().put("index.number_of_shards", 3) // 分片数
                        .put("index.number_of_replicas", 2) // 副本数
                        .put("analysis.analyzer.default.tokenizer", "ik_smart") // 默认分词器
                );
    
                // 3、设置索引的mappings
                request.mapping("_doc",
                        "  {
    " +
                        "    "_doc": {
    " +
                        "      "properties": {
    " +
                        "        "message": {
    " +
                        "          "type": "text"
    " +
                        "        }
    " +
                        "      }
    " +
                        "    }
    " +
                        "  }",
                        XContentType.JSON);
    
                // 4、 设置索引的别名
                request.alias(new Alias("mmm"));
    
                // 5、 发送请求
                // 5.1 同步方式发送请求
                CreateIndexResponse createIndexResponse = client.indices()
                        .create(request);
    
                // 6、处理响应
                boolean acknowledged = createIndexResponse.isAcknowledged();
                boolean shardsAcknowledged = createIndexResponse
                        .isShardsAcknowledged();
                System.out.println("acknowledged = " + acknowledged);
                System.out.println("shardsAcknowledged = " + shardsAcknowledged);
    
                // 5.1 异步方式发送请求
                /*ActionListener<CreateIndexResponse> listener = new ActionListener<CreateIndexResponse>() {
                    @Override
                    public void onResponse(
                            CreateIndexResponse createIndexResponse) {
                        // 6、处理响应
                        boolean acknowledged = createIndexResponse.isAcknowledged();
                        boolean shardsAcknowledged = createIndexResponse
                                .isShardsAcknowledged();
                        System.out.println("acknowledged = " + acknowledged);
                        System.out.println(
                                "shardsAcknowledged = " + shardsAcknowledged);
                    }
    
                    @Override
                    public void onFailure(Exception e) {
                        System.out.println("创建索引异常:" + e.getMessage());
                    }
                };
    
                client.indices().createAsync(request, listener);
                */
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

     运行结果:

    acknowledged = true
    shardsAcknowledged = true

    2. index  document

     索引文档,即往索引里面放入文档数据.类似于数据库里面向表里面插入一行数据,一行数据就是一个文档

     IndexDocumentDemo.java

    package com.study.es_hrset_client;
    
    import java.io.IOException;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.ElasticsearchException;
    import org.elasticsearch.action.DocWriteResponse;
    import org.elasticsearch.action.index.IndexRequest;
    import org.elasticsearch.action.index.IndexResponse;
    import org.elasticsearch.action.support.replication.ReplicationResponse;
    import org.elasticsearch.client.RestHighLevelClient;
    import org.elasticsearch.common.xcontent.XContentType;
    import org.elasticsearch.rest.RestStatus;
    
    /**
     * 
     * @Description: 索引文档,即往索引里面放入文档数据.类似于数据库里面向表里面插入一行数据,一行数据就是一个文档
     * @author lgs
     * @date 2018年6月23日
     *
     */
    public class IndexDocumentDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
    
        public static void main(String[] args) {
            try (RestHighLevelClient client = InitDemo.getClient();) {
                // 1、创建索引请求
                IndexRequest request = new IndexRequest(
                        "mess",   //索引
                        "_doc",     // mapping type
                        "1");     //文档id  
                
                // 2、准备文档数据
                // 方式一:直接给JSON串
                String jsonString = "{" +
                        ""user":"kimchy"," +
                        ""postDate":"2013-01-30"," +
                        ""message":"trying out Elasticsearch"" +
                        "}";
                request.source(jsonString, XContentType.JSON); 
                
                // 方式二:以map对象来表示文档
                /*
                Map<String, Object> jsonMap = new HashMap<>();
                jsonMap.put("user", "kimchy");
                jsonMap.put("postDate", new Date());
                jsonMap.put("message", "trying out Elasticsearch");
                request.source(jsonMap); 
                */
                
                // 方式三:用XContentBuilder来构建文档
                /*
                XContentBuilder builder = XContentFactory.jsonBuilder();
                builder.startObject();
                {
                    builder.field("user", "kimchy");
                    builder.field("postDate", new Date());
                    builder.field("message", "trying out Elasticsearch");
                }
                builder.endObject();
                request.source(builder); 
                */
                
                // 方式四:直接用key-value对给出
                /*
                request.source("user", "kimchy",
                                "postDate", new Date(),
                                "message", "trying out Elasticsearch");
                */
                
                //3、其他的一些可选设置
                /*
                request.routing("routing");  //设置routing值
                request.timeout(TimeValue.timeValueSeconds(1));  //设置主分片等待时长
                request.setRefreshPolicy("wait_for");  //设置重刷新策略
                request.version(2);  //设置版本号
                request.opType(DocWriteRequest.OpType.CREATE);  //操作类别  
                */
                
                //4、发送请求
                IndexResponse indexResponse = null;
                try {
                    // 同步方式
                    indexResponse = client.index(request);            
                } catch(ElasticsearchException e) {
                    // 捕获,并处理异常
                    //判断是否版本冲突、create但文档已存在冲突
                    if (e.status() == RestStatus.CONFLICT) {
                        logger.error("冲突了,请在此写冲突处理逻辑!
    " + e.getDetailedMessage());
                    }
                    
                    logger.error("索引异常", e);
                }
                
                //5、处理响应
                if(indexResponse != null) {
                    String index = indexResponse.getIndex();
                    String type = indexResponse.getType();
                    String id = indexResponse.getId();
                    long version = indexResponse.getVersion();
                    if (indexResponse.getResult() == DocWriteResponse.Result.CREATED) {
                        System.out.println("新增文档成功,处理逻辑代码写到这里。");
                    } else if (indexResponse.getResult() == DocWriteResponse.Result.UPDATED) {
                        System.out.println("修改文档成功,处理逻辑代码写到这里。");
                    }
                    // 分片处理信息
                    ReplicationResponse.ShardInfo shardInfo = indexResponse.getShardInfo();
                    if (shardInfo.getTotal() != shardInfo.getSuccessful()) {
                        
                    }
                    // 如果有分片副本失败,可以获得失败原因信息
                    if (shardInfo.getFailed() > 0) {
                        for (ReplicationResponse.ShardInfo.Failure failure : shardInfo.getFailures()) {
                            String reason = failure.reason(); 
                            System.out.println("副本失败原因:" + reason);
                        }
                    }
                }
                
                
                //异步方式发送索引请求
                /*ActionListener<IndexResponse> listener = new ActionListener<IndexResponse>() {
                    @Override
                    public void onResponse(IndexResponse indexResponse) {
                        
                    }
    
                    @Override
                    public void onFailure(Exception e) {
                        
                    }
                };
                client.indexAsync(request, listener);
                */
                
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

     运行结果:

    新增文档成功,处理逻辑代码写到这里。

    3. get  document

     获取文档数据

     GetDocumentDemo.java

    package com.study.es_hrset_client;
    
    import java.io.IOException;
    import java.util.Map;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.ElasticsearchException;
    import org.elasticsearch.action.get.GetRequest;
    import org.elasticsearch.action.get.GetResponse;
    import org.elasticsearch.client.RestHighLevelClient;
    import org.elasticsearch.common.Strings;
    import org.elasticsearch.rest.RestStatus;
    import org.elasticsearch.search.fetch.subphase.FetchSourceContext;
    
    /**
     * 
     * @Description: 获取文档数据
     * @author lgs
     * @date 2018年6月23日
     *
     */
    public class GetDocumentDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
    
        public static void main(String[] args) {
            try (RestHighLevelClient client = InitDemo.getClient();) {
                // 1、创建获取文档请求
                GetRequest request = new GetRequest(
                        "mess",   //索引
                        "_doc",     // mapping type
                        "1");     //文档id  
                
                // 2、可选的设置
                //request.routing("routing");
                //request.version(2);
                
                //request.fetchSourceContext(new FetchSourceContext(false)); //是否获取_source字段
                //选择返回的字段
                String[] includes = new String[]{"message", "*Date"};
                String[] excludes = Strings.EMPTY_ARRAY;
                FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
                request.fetchSourceContext(fetchSourceContext); 
                
                //也可写成这样
                /*String[] includes = Strings.EMPTY_ARRAY;
                String[] excludes = new String[]{"message"};
                FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
                request.fetchSourceContext(fetchSourceContext);*/
                
                
                // 取stored字段
                /*request.storedFields("message"); 
                GetResponse getResponse = client.get(request);
                String message = getResponse.getField("message").getValue();*/
                
                
                //3、发送请求        
                GetResponse getResponse = null;
                try {
                    // 同步请求
                    getResponse = client.get(request);
                } catch (ElasticsearchException e) {
                    if (e.status() == RestStatus.NOT_FOUND) {
                        logger.error("没有找到该id的文档" );
                    }
                    if (e.status() == RestStatus.CONFLICT) {
                        logger.error("获取时版本冲突了,请在此写冲突处理逻辑!" );
                    }
                    logger.error("获取文档异常", e);
                }
                
                //4、处理响应
                if(getResponse != null) {
                    String index = getResponse.getIndex();
                    String type = getResponse.getType();
                    String id = getResponse.getId();
                    if (getResponse.isExists()) { // 文档存在
                        long version = getResponse.getVersion();
                        String sourceAsString = getResponse.getSourceAsString(); //结果取成 String       
                        Map<String, Object> sourceAsMap = getResponse.getSourceAsMap();  // 结果取成Map
                        byte[] sourceAsBytes = getResponse.getSourceAsBytes();    //结果取成字节数组
                        
                        logger.info("index:" + index + "  type:" + type + "  id:" + id);
                        logger.info(sourceAsString);
                        
                    } else {
                        logger.error("没有找到该id的文档" );
                    }
                }
                
                
                //异步方式发送获取文档请求
                /*
                ActionListener<GetResponse> listener = new ActionListener<GetResponse>() {
                    @Override
                    public void onResponse(GetResponse getResponse) {
                        
                    }
                
                    @Override
                    public void onFailure(Exception e) {
                        
                    }
                };
                client.getAsync(request, listener);
                */
                
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

     4. Bulk 

     批量索引文档,即批量往索引里面放入文档数据.类似于数据库里面批量向表里面插入多行数据,一行数据就是一个文档

     BulkDemo.java

    package com.study.es_hrset_client;
    
    import java.io.IOException;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.action.DocWriteRequest;
    import org.elasticsearch.action.DocWriteResponse;
    import org.elasticsearch.action.bulk.BulkItemResponse;
    import org.elasticsearch.action.bulk.BulkRequest;
    import org.elasticsearch.action.bulk.BulkResponse;
    import org.elasticsearch.action.delete.DeleteResponse;
    import org.elasticsearch.action.index.IndexRequest;
    import org.elasticsearch.action.index.IndexResponse;
    import org.elasticsearch.action.update.UpdateResponse;
    import org.elasticsearch.client.RestHighLevelClient;
    import org.elasticsearch.common.xcontent.XContentType;
    
    /**
     * 
     * @Description: 批量索引文档,即批量往索引里面放入文档数据.类似于数据库里面批量向表里面插入多行数据,一行数据就是一个文档
     * @author lgs
     * @date 2018年6月23日
     *
     */
    public class BulkDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
    
        public static void main(String[] args) {
            try (RestHighLevelClient client = InitDemo.getClient();) {
                
                // 1、创建批量操作请求
                BulkRequest request = new BulkRequest(); 
                request.add(new IndexRequest("mess", "_doc", "1")  
                        .source(XContentType.JSON,"field", "foo"));
                request.add(new IndexRequest("mess", "_doc", "2")  
                        .source(XContentType.JSON,"field", "bar"));
                request.add(new IndexRequest("mess", "_doc", "3")  
                        .source(XContentType.JSON,"field", "baz"));
                
                /*
                request.add(new DeleteRequest("mess", "_doc", "3")); 
                request.add(new UpdateRequest("mess", "_doc", "2") 
                        .doc(XContentType.JSON,"other", "test"));
                request.add(new IndexRequest("mess", "_doc", "4")  
                        .source(XContentType.JSON,"field", "baz"));
                */
                
                // 2、可选的设置
                /*
                request.timeout("2m");
                request.setRefreshPolicy("wait_for");  
                request.waitForActiveShards(2);
                */
                
                
                //3、发送请求        
            
                // 同步请求
                BulkResponse bulkResponse = client.bulk(request);
                
                
                //4、处理响应
                if(bulkResponse != null) {
                    for (BulkItemResponse bulkItemResponse : bulkResponse) { 
                        DocWriteResponse itemResponse = bulkItemResponse.getResponse(); 
    
                        if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.INDEX
                                || bulkItemResponse.getOpType() == DocWriteRequest.OpType.CREATE) { 
                            IndexResponse indexResponse = (IndexResponse) itemResponse;
                            //TODO 新增成功的处理
    
                        } else if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.UPDATE) { 
                            UpdateResponse updateResponse = (UpdateResponse) itemResponse;
                           //TODO 修改成功的处理
    
                        } else if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.DELETE) { 
                            DeleteResponse deleteResponse = (DeleteResponse) itemResponse;
                            //TODO 删除成功的处理
                        }
                    }
                }
                
                
                //异步方式发送批量操作请求
                /*
                ActionListener<BulkResponse> listener = new ActionListener<BulkResponse>() {
                    @Override
                    public void onResponse(BulkResponse bulkResponse) {
                        
                    }
                
                    @Override
                    public void onFailure(Exception e) {
                        
                    }
                };
                client.bulkAsync(request, listener);
                */
                
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

     5. search

     搜索数据

     SearchDemo.java

    package com.study.es_hrset_client;
    
    import java.io.IOException;
    import java.util.List;
    import java.util.Map;
    import java.util.concurrent.TimeUnit;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.action.search.SearchRequest;
    import org.elasticsearch.action.search.SearchResponse;
    import org.elasticsearch.action.search.ShardSearchFailure;
    import org.elasticsearch.client.RestHighLevelClient;
    import org.elasticsearch.common.unit.TimeValue;
    import org.elasticsearch.index.query.QueryBuilders;
    import org.elasticsearch.rest.RestStatus;
    import org.elasticsearch.search.SearchHit;
    import org.elasticsearch.search.SearchHits;
    import org.elasticsearch.search.builder.SearchSourceBuilder;
    import org.elasticsearch.search.suggest.Suggest;
    import org.elasticsearch.search.suggest.term.TermSuggestion;
    
    /**
     * 
     * @Description: 搜索数据
     * @author lgs
     * @date 2018年6月23日
     *
     */
    public class SearchDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
    
        public static void main(String[] args) {
            try (RestHighLevelClient client = InitDemo.getClient();) {
                
                // 1、创建search请求
                //SearchRequest searchRequest = new SearchRequest();
                SearchRequest searchRequest = new SearchRequest("bank"); 
                searchRequest.types("_doc");
                
                // 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法,构造各种查询的方法都在这。
                SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
                
                //构造QueryBuilder
                /*QueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("user", "kimchy")
                        .fuzziness(Fuzziness.AUTO)
                        .prefixLength(3)
                        .maxExpansions(10);
                sourceBuilder.query(matchQueryBuilder);*/
                
                sourceBuilder.query(QueryBuilders.termQuery("age", 24)); 
                sourceBuilder.from(0); 
                sourceBuilder.size(10); 
                sourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS)); 
                
                //是否返回_source字段
                //sourceBuilder.fetchSource(false);
                
                //设置返回哪些字段
                /*String[] includeFields = new String[] {"title", "user", "innerObject.*"};
                String[] excludeFields = new String[] {"_type"};
                sourceBuilder.fetchSource(includeFields, excludeFields);*/
                
                //指定排序
                //sourceBuilder.sort(new ScoreSortBuilder().order(SortOrder.DESC)); 
                //sourceBuilder.sort(new FieldSortBuilder("_uid").order(SortOrder.ASC));
                
                // 设置返回 profile 
                //sourceBuilder.profile(true);
                
                //将请求体加入到请求中
                searchRequest.source(sourceBuilder);
                
                // 可选的设置
                //searchRequest.routing("routing");
                
                // 高亮设置
                /*
                HighlightBuilder highlightBuilder = new HighlightBuilder(); 
                HighlightBuilder.Field highlightTitle =
                        new HighlightBuilder.Field("title"); 
                highlightTitle.highlighterType("unified");  
                highlightBuilder.field(highlightTitle);  
                HighlightBuilder.Field highlightUser = new HighlightBuilder.Field("user");
                highlightBuilder.field(highlightUser);
                sourceBuilder.highlighter(highlightBuilder);*/
                
                
                //加入聚合
                /*TermsAggregationBuilder aggregation = AggregationBuilders.terms("by_company")
                        .field("company.keyword");
                aggregation.subAggregation(AggregationBuilders.avg("average_age")
                        .field("age"));
                sourceBuilder.aggregation(aggregation);*/
                
                //做查询建议
                /*SuggestionBuilder termSuggestionBuilder =
                        SuggestBuilders.termSuggestion("user").text("kmichy"); 
                    SuggestBuilder suggestBuilder = new SuggestBuilder();
                    suggestBuilder.addSuggestion("suggest_user", termSuggestionBuilder); 
                sourceBuilder.suggest(suggestBuilder);*/
                
                //3、发送请求        
                SearchResponse searchResponse = client.search(searchRequest);
                
                
                //4、处理响应
                //搜索结果状态信息
                RestStatus status = searchResponse.status();
                TimeValue took = searchResponse.getTook();
                Boolean terminatedEarly = searchResponse.isTerminatedEarly();
                boolean timedOut = searchResponse.isTimedOut();
                
                //分片搜索情况
                int totalShards = searchResponse.getTotalShards();
                int successfulShards = searchResponse.getSuccessfulShards();
                int failedShards = searchResponse.getFailedShards();
                for (ShardSearchFailure failure : searchResponse.getShardFailures()) {
                    // failures should be handled here
                }
                
                //处理搜索命中文档结果
                SearchHits hits = searchResponse.getHits();
                
                long totalHits = hits.getTotalHits();
                float maxScore = hits.getMaxScore();
                
                SearchHit[] searchHits = hits.getHits();
                for (SearchHit hit : searchHits) {
                    // do something with the SearchHit
                    
                    String index = hit.getIndex();
                    String type = hit.getType();
                    String id = hit.getId();
                    float score = hit.getScore();
                    
                    //取_source字段值
                    String sourceAsString = hit.getSourceAsString(); //取成json串
                    Map<String, Object> sourceAsMap = hit.getSourceAsMap(); // 取成map对象
                    //从map中取字段值
                    /*
                    String documentTitle = (String) sourceAsMap.get("title"); 
                    List<Object> users = (List<Object>) sourceAsMap.get("user");
                    Map<String, Object> innerObject = (Map<String, Object>) sourceAsMap.get("innerObject");
                    */
                    logger.info("index:" + index + "  type:" + type + "  id:" + id);
                    logger.info(sourceAsString);
                    
                    //取高亮结果
                    /*Map<String, HighlightField> highlightFields = hit.getHighlightFields();
                    HighlightField highlight = highlightFields.get("title"); 
                    Text[] fragments = highlight.fragments();  
                    String fragmentString = fragments[0].string();*/
                }
                
                // 获取聚合结果
                /*
                Aggregations aggregations = searchResponse.getAggregations();
                Terms byCompanyAggregation = aggregations.get("by_company"); 
                Bucket elasticBucket = byCompanyAggregation.getBucketByKey("Elastic"); 
                Avg averageAge = elasticBucket.getAggregations().get("average_age"); 
                double avg = averageAge.getValue();
                */
                
                // 获取建议结果
                /*Suggest suggest = searchResponse.getSuggest(); 
                TermSuggestion termSuggestion = suggest.getSuggestion("suggest_user"); 
                for (TermSuggestion.Entry entry : termSuggestion.getEntries()) { 
                    for (TermSuggestion.Entry.Option option : entry) { 
                        String suggestText = option.getText().string();
                    }
                }
                */
                
                //异步方式发送获查询请求
                /*
                ActionListener<SearchResponse> listener = new ActionListener<SearchResponse>() {
                    @Override
                    public void onResponse(SearchResponse getResponse) {
                        //结果获取
                    }
                
                    @Override
                    public void onFailure(Exception e) {
                        //失败处理
                    }
                };
                client.searchAsync(searchRequest, listener); 
                */
                
            } catch (IOException e) {
                logger.error(e);
            }
        }
    }

     6. highlight 高亮

    HighlightDemo.java

    package com.study.es_hrset_client;
    
    import java.io.IOException;
    import java.util.Map;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.action.search.SearchRequest;
    import org.elasticsearch.action.search.SearchResponse;
    import org.elasticsearch.client.RestHighLevelClient;
    import org.elasticsearch.common.text.Text;
    import org.elasticsearch.index.query.QueryBuilder;
    import org.elasticsearch.index.query.QueryBuilders;
    import org.elasticsearch.rest.RestStatus;
    import org.elasticsearch.search.SearchHit;
    import org.elasticsearch.search.SearchHits;
    import org.elasticsearch.search.builder.SearchSourceBuilder;
    import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
    import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
    
    /**
     * 
     * @Description: 高亮
     * @author lgs
     * @date 2018年6月23日
     *
     */
    public class HighlightDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
    
        public static void main(String[] args) {
            try (RestHighLevelClient client = InitDemo.getClient();) {
                
                // 1、创建search请求
                SearchRequest searchRequest = new SearchRequest("hl_test"); 
                
                // 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法,构造各种查询的方法都在这。
                SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
                
                //构造QueryBuilder
                QueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("title", "lucene solr");
                sourceBuilder.query(matchQueryBuilder);
                
                //分页设置
                /*sourceBuilder.from(0); 
                sourceBuilder.size(5); ;*/ 
                
                        
                // 高亮设置
                HighlightBuilder highlightBuilder = new HighlightBuilder(); 
                highlightBuilder.requireFieldMatch(false).field("title").field("content")
                    .preTags("<strong>").postTags("</strong>");
                //不同字段可有不同设置,如不同标签
                /*HighlightBuilder.Field highlightTitle = new HighlightBuilder.Field("title"); 
                highlightTitle.preTags("<strong>").postTags("</strong>");
                highlightBuilder.field(highlightTitle);  
                HighlightBuilder.Field highlightContent = new HighlightBuilder.Field("content");
                highlightContent.preTags("<b>").postTags("</b>");
                highlightBuilder.field(highlightContent).requireFieldMatch(false);*/
                
                sourceBuilder.highlighter(highlightBuilder);
                
                searchRequest.source(sourceBuilder);
                
                //3、发送请求        
                SearchResponse searchResponse = client.search(searchRequest);
                
                
                //4、处理响应
                if(RestStatus.OK.equals(searchResponse.status())) {
                    //处理搜索命中文档结果
                    SearchHits hits = searchResponse.getHits();
                    long totalHits = hits.getTotalHits();
                    
                    SearchHit[] searchHits = hits.getHits();
                    for (SearchHit hit : searchHits) {        
                        String index = hit.getIndex();
                        String type = hit.getType();
                        String id = hit.getId();
                        float score = hit.getScore();
                        
                        //取_source字段值
                        //String sourceAsString = hit.getSourceAsString(); //取成json串
                        Map<String, Object> sourceAsMap = hit.getSourceAsMap(); // 取成map对象
                        //从map中取字段值
                        /*String title = (String) sourceAsMap.get("title"); 
                        String content  = (String) sourceAsMap.get("content"); */
                        logger.info("index:" + index + "  type:" + type + "  id:" + id);
                        logger.info("sourceMap : " +  sourceAsMap);
                        //取高亮结果
                        Map<String, HighlightField> highlightFields = hit.getHighlightFields();
                        HighlightField highlight = highlightFields.get("title"); 
                        if(highlight != null) {
                            Text[] fragments = highlight.fragments();  //多值的字段会有多个值
                            if(fragments != null) {
                                String fragmentString = fragments[0].string();
                                logger.info("title highlight : " +  fragmentString);
                                //可用高亮字符串替换上面sourceAsMap中的对应字段返回到上一级调用
                                //sourceAsMap.put("title", fragmentString);
                            }
                        }
                        
                        highlight = highlightFields.get("content"); 
                        if(highlight != null) {
                            Text[] fragments = highlight.fragments();  //多值的字段会有多个值
                            if(fragments != null) {
                                String fragmentString = fragments[0].string();
                                logger.info("content highlight : " +  fragmentString);
                                //可用高亮字符串替换上面sourceAsMap中的对应字段返回到上一级调用
                                //sourceAsMap.put("content", fragmentString);
                            }
                        }
                    }
                }
                
            } catch (IOException e) {
                logger.error(e);
            }
        }
    }

     7. suggest 查询建议

    SuggestDemo.java

    package com.study.es_hrset_client;
    
    import java.io.IOException;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.action.search.SearchRequest;
    import org.elasticsearch.action.search.SearchResponse;
    import org.elasticsearch.client.RestHighLevelClient;
    import org.elasticsearch.rest.RestStatus;
    import org.elasticsearch.search.builder.SearchSourceBuilder;
    import org.elasticsearch.search.suggest.Suggest;
    import org.elasticsearch.search.suggest.SuggestBuilder;
    import org.elasticsearch.search.suggest.SuggestBuilders;
    import org.elasticsearch.search.suggest.SuggestionBuilder;
    import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
    import org.elasticsearch.search.suggest.term.TermSuggestion;
    
    /**
     * 
     * @Description: 查询建议
     * @author lgs
     * @date 2018年6月23日
     *
     */
    public class SuggestDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
        
        //词项建议拼写检查,检查用户的拼写是否错误,如果有错给用户推荐正确的词,appel->apple
        public static void termSuggest() {
            try (RestHighLevelClient client = InitDemo.getClient();) {
                
                // 1、创建search请求
                //SearchRequest searchRequest = new SearchRequest();
                SearchRequest searchRequest = new SearchRequest("mess"); 
                
                // 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法,构造各种查询的方法都在这。
                SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
                 
                sourceBuilder.size(0); 
                
                //做查询建议        
                //词项建议
                SuggestionBuilder termSuggestionBuilder =
                        SuggestBuilders.termSuggestion("user").text("kmichy"); 
                SuggestBuilder suggestBuilder = new SuggestBuilder();
                suggestBuilder.addSuggestion("suggest_user", termSuggestionBuilder);     
                sourceBuilder.suggest(suggestBuilder);
                
                searchRequest.source(sourceBuilder);    
                
                //3、发送请求        
                SearchResponse searchResponse = client.search(searchRequest);
                
                
                //4、处理响应
                //搜索结果状态信息
                if(RestStatus.OK.equals(searchResponse.status())) {
                    // 获取建议结果
                    Suggest suggest = searchResponse.getSuggest(); 
                    TermSuggestion termSuggestion = suggest.getSuggestion("suggest_user"); 
                    for (TermSuggestion.Entry entry : termSuggestion.getEntries()) { 
                        logger.info("text: " + entry.getText().string());
                        for (TermSuggestion.Entry.Option option : entry) { 
                            String suggestText = option.getText().string();
                            logger.info("   suggest option : " + suggestText);
                        }
                    }
                }
                /*
                  "suggest": {
                    "my-suggestion": [
                      {
                        "text": "tring",
                        "offset": 0,
                        "length": 5,
                        "options": [
                          {
                            "text": "trying",
                            "score": 0.8,
                            "freq": 1
                          }
                        ]
                      },
                      {
                        "text": "out",
                        "offset": 6,
                        "length": 3,
                        "options": []
                      },
                      {
                        "text": "elasticsearch",
                        "offset": 10,
                        "length": 13,
                        "options": []
                      }
                    ]
                  }*/
    
            } catch (IOException e) {
                logger.error(e);
            }
        }
        
        //自动补全,根据用户的输入联想到可能的词或者短语
        public static void completionSuggester() {
            try (RestHighLevelClient client = InitDemo.getClient();) {
                
                // 1、创建search请求
                //SearchRequest searchRequest = new SearchRequest();
                SearchRequest searchRequest = new SearchRequest("music"); 
                
                // 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法,构造各种查询的方法都在这。
                SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
                 
                sourceBuilder.size(0); 
                
                //做查询建议        
                //自动补全
                /*POST music/_search?pretty
                        {
                            "suggest": {
                                "song-suggest" : {
                                    "prefix" : "lucene s", 
                                    "completion" : { 
                                        "field" : "suggest" ,
                                        "skip_duplicates": true
                                    }
                                }
                            }
                        }*/
    
                SuggestionBuilder termSuggestionBuilder =
                        SuggestBuilders.completionSuggestion("suggest").prefix("lucene s")
                        .skipDuplicates(true); 
                SuggestBuilder suggestBuilder = new SuggestBuilder();
                suggestBuilder.addSuggestion("song-suggest", termSuggestionBuilder);     
                sourceBuilder.suggest(suggestBuilder);
                
                searchRequest.source(sourceBuilder);    
                
                //3、发送请求        
                SearchResponse searchResponse = client.search(searchRequest);
                
                
                //4、处理响应
                //搜索结果状态信息
                if(RestStatus.OK.equals(searchResponse.status())) {
                    // 获取建议结果
                    Suggest suggest = searchResponse.getSuggest(); 
                    CompletionSuggestion termSuggestion = suggest.getSuggestion("song-suggest"); 
                    for (CompletionSuggestion.Entry entry : termSuggestion.getEntries()) { 
                        logger.info("text: " + entry.getText().string());
                        for (CompletionSuggestion.Entry.Option option : entry) { 
                            String suggestText = option.getText().string();
                            logger.info("   suggest option : " + suggestText);
                        }
                    }
                }
    
            } catch (IOException e) {
                logger.error(e);
            }
        }
    
        public static void main(String[] args) {
            termSuggest();
            
            logger.info("--------------------------------------");
            
            completionSuggester();
        }
    }

     8. aggregation 聚合分析

     AggregationDemo.java

    package com.study.es_hrset_client;
    
    import java.io.IOException;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.action.search.SearchRequest;
    import org.elasticsearch.action.search.SearchResponse;
    import org.elasticsearch.client.RestHighLevelClient;
    import org.elasticsearch.rest.RestStatus;
    import org.elasticsearch.search.aggregations.AggregationBuilders;
    import org.elasticsearch.search.aggregations.Aggregations;
    import org.elasticsearch.search.aggregations.BucketOrder;
    import org.elasticsearch.search.aggregations.bucket.terms.Terms;
    import org.elasticsearch.search.aggregations.bucket.terms.Terms.Bucket;
    import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
    import org.elasticsearch.search.aggregations.metrics.avg.Avg;
    import org.elasticsearch.search.builder.SearchSourceBuilder;
    
    /**
     * 
     * @Description: 聚合分析
     * @author lgs
     * @date 2018年6月23日
     *
     */
    public class AggregationDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
    
        public static void main(String[] args) {
            try (RestHighLevelClient client = InitDemo.getClient();) {
                
                // 1、创建search请求
                //SearchRequest searchRequest = new SearchRequest();
                SearchRequest searchRequest = new SearchRequest("bank"); 
                
                // 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法,构造各种查询的方法都在这。
                SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
                 
                sourceBuilder.size(0); 
    
                //加入聚合
                //字段值项分组聚合
                TermsAggregationBuilder aggregation = AggregationBuilders.terms("by_age")
                        .field("age").order(BucketOrder.aggregation("average_balance", true));
                //计算每组的平均balance指标
                aggregation.subAggregation(AggregationBuilders.avg("average_balance")
                        .field("balance"));
                sourceBuilder.aggregation(aggregation);
                
                searchRequest.source(sourceBuilder);
                
                //3、发送请求        
                SearchResponse searchResponse = client.search(searchRequest);
                    
                //4、处理响应
                //搜索结果状态信息
                if(RestStatus.OK.equals(searchResponse.status())) {
                    // 获取聚合结果
                    Aggregations aggregations = searchResponse.getAggregations();
                    Terms byAgeAggregation = aggregations.get("by_age"); 
                    logger.info("aggregation by_age 结果");
                    logger.info("docCountError: " + byAgeAggregation.getDocCountError());
                    logger.info("sumOfOtherDocCounts: " + byAgeAggregation.getSumOfOtherDocCounts());
                    logger.info("------------------------------------");
                    for(Bucket buck : byAgeAggregation.getBuckets()) {
                        logger.info("key: " + buck.getKeyAsNumber());
                        logger.info("docCount: " + buck.getDocCount());
                        logger.info("docCountError: " + buck.getDocCountError());
                        //取子聚合
                        Avg averageBalance = buck.getAggregations().get("average_balance"); 
    
                        logger.info("average_balance: " + averageBalance.getValue());
                        logger.info("------------------------------------");
                    }
                    //直接用key 来去分组
                    /*Bucket elasticBucket = byCompanyAggregation.getBucketByKey("24"); 
                    Avg averageAge = elasticBucket.getAggregations().get("average_age"); 
                    double avg = averageAge.getValue();*/
                    
                }
                
            } catch (IOException e) {
                logger.error(e);
            }
        }
    }

     9. 官网资料

    各种查询对应的QueryBuilder:

    https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-query-builders.html

    各种聚合对应的AggregationBuilder:

    https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-aggregation-builders.html

    四、Java Client

    1. Java Client 说明

    java client 使用 TransportClient,各种操作本质上都是异步的(可以用 listener,或返回 Future )。 
    注意:ES的发展规划中在7.0版本开始将废弃 TransportClient,8.0版本中将完全移除 TransportClient,取而代之的是High Level REST Client。
    High Level REST Client 中的操作API和java client 大多是一样的。

    2. 官方学习链接

    https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/index.html

    3. 兼容性说明

    请使用与服务端ES版本一致的客户端版本

    4. Java Client maven 集成

    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>transport</artifactId>
        <version>6.2.4</version>
    </dependency>

    5. Java Client logger 日志器说明

    使用的是 log4j2 日志组件。
    如果要使用其他的日志组件,可使用slf4j作桥

    6. Init Client

    Init Client setting 可用参数说明:

    cluster.name
    指定集群的名字,如果集群的名字不是默认的elasticsearch,需指定。
    client.transport.sniff
    设置为true,将自动嗅探整个集群,自动加入集群的节点到连接列表中。
    client.transport.ignore_cluster_name
    Set to true to ignore cluster name validation of connected nodes. (since 0.19.4)
    client.transport.ping_timeout
    The time to wait for a ping response from a node. Defaults to 5s.
    client.transport.nodes_sampler_interval
    How often to sample / ping the nodes listed and connected. Defaults to 5s.

    五、Java Client使用示例

    注意:TransPort客户端的使用和RESTful风格的使用基本一致,除了获取客户端不一样,还有发送请求有的不一样外

    准备:

    编写示例之前首先在maven工程里面引入和ES服务端版本一样的Java客户端

        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>transport</artifactId>
            <version>6.2.4</version>
        </dependency>

    给定集群的多个节点地址,将客户端负载均衡地向这个节点地址集发请求:

    InitDemo.java

    package com.study.es_java_client;
    
    import java.net.InetAddress;
    import java.net.UnknownHostException;
    
    import org.elasticsearch.client.transport.TransportClient;
    import org.elasticsearch.common.settings.Settings;
    import org.elasticsearch.common.transport.TransportAddress;
    import org.elasticsearch.transport.client.PreBuiltTransportClient;
    
    public class InitDemo {
        
        private static TransportClient client;
    
        public static TransportClient getClient() throws UnknownHostException {
    
            if(client == null) {
                //client = new PreBuiltTransportClient(Settings.EMPTY)
                
                // 连接集群的设置
                Settings settings = Settings.builder()
                        //.put("cluster.name", "myClusterName") //如果集群的名字不是默认的elasticsearch,需指定
                        .put("client.transport.sniff", true) //自动嗅探
                        .build();   
                client = new PreBuiltTransportClient(settings)
                    //.addTransportAddress(new TransportAddress(InetAddress.getByName("localhost"), 9300));
                    .addTransportAddress(new TransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
                
                //可用连接设置参数说明
                /*
                cluster.name
                    指定集群的名字,如果集群的名字不是默认的elasticsearch,需指定。
                client.transport.sniff
                    设置为true,将自动嗅探整个集群,自动加入集群的节点到连接列表中。    
                client.transport.ignore_cluster_name
                    Set to true to ignore cluster name validation of connected nodes. (since 0.19.4)    
                client.transport.ping_timeout
                    The time to wait for a ping response from a node. Defaults to 5s.
                client.transport.nodes_sampler_interval
                    How often to sample / ping the nodes listed and connected. Defaults to 5s.
                */
                
            }
            return client;
        }
    }

    注意使用ES的客户端时类比之前我们在Kibana进行的ES的相关操作,这样使用起来更加有效果

    1. Create index 创建索引

    CreateIndexDemo.java

    package com.study.es_java_client;
    
    import java.io.IOException;
    import java.util.concurrent.ExecutionException;
    
    import org.elasticsearch.action.admin.indices.alias.Alias;
    import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
    import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
    import org.elasticsearch.client.transport.TransportClient;
    import org.elasticsearch.common.settings.Settings;
    import org.elasticsearch.common.xcontent.XContentType;
    
    public class CreateIndexDemo {
    
        public static void main(String[] args) {
            //这里和RESTful风格不同
            try (TransportClient client = InitDemo.getClient();) {
    
                // 1、创建 创建索引request
                CreateIndexRequest request = new CreateIndexRequest("mess");
    
                // 2、设置索引的settings
                request.settings(Settings.builder().put("index.number_of_shards", 3) // 分片数
                        .put("index.number_of_replicas", 2) // 副本数
                        .put("analysis.analyzer.default.tokenizer", "ik_smart") // 默认分词器
                );
    
                // 3、设置索引的mappings
                request.mapping("_doc",
                        "  {
    " +
                        "    "_doc": {
    " +
                        "      "properties": {
    " +
                        "        "message": {
    " +
                        "          "type": "text"
    " +
                        "        }
    " +
                        "      }
    " +
                        "    }
    " +
                        "  }",
                        XContentType.JSON);
    
                // 4、 设置索引的别名
                request.alias(new Alias("mmm"));
    
                // 5、 发送请求 这里和RESTful风格不同
                CreateIndexResponse createIndexResponse = client.admin().indices()
                        .create(request).get();
    
                // 6、处理响应
                boolean acknowledged = createIndexResponse.isAcknowledged();
                boolean shardsAcknowledged = createIndexResponse
                        .isShardsAcknowledged();
                System.out.println("acknowledged = " + acknowledged);
                System.out.println("shardsAcknowledged = " + shardsAcknowledged);
    
                // listener方式发送请求
                /*ActionListener<CreateIndexResponse> listener = new ActionListener<CreateIndexResponse>() {
                    @Override
                    public void onResponse(
                            CreateIndexResponse createIndexResponse) {
                        // 6、处理响应
                        boolean acknowledged = createIndexResponse.isAcknowledged();
                        boolean shardsAcknowledged = createIndexResponse
                                .isShardsAcknowledged();
                        System.out.println("acknowledged = " + acknowledged);
                        System.out.println(
                                "shardsAcknowledged = " + shardsAcknowledged);
                    }
    
                    @Override
                    public void onFailure(Exception e) {
                        System.out.println("创建索引异常:" + e.getMessage());
                    }
                };
                client.admin().indices().create(request, listener);
                */
            } catch (IOException | InterruptedException | ExecutionException e) {
                e.printStackTrace();
            }
        }
    }

    复制代码

    2. index document

    索引文档,即往索引里面放入文档数据.类似于数据库里面向表里面插入一行数据,一行数据就是一个文档
    IndexDocumentDemo.java

    package com.study.es_java_client;
    
    import java.io.IOException;
    import java.util.concurrent.ExecutionException;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.ElasticsearchException;
    import org.elasticsearch.action.DocWriteResponse;
    import org.elasticsearch.action.index.IndexRequest;
    import org.elasticsearch.action.index.IndexResponse;
    import org.elasticsearch.action.support.replication.ReplicationResponse;
    import org.elasticsearch.client.transport.TransportClient;
    import org.elasticsearch.common.xcontent.XContentType;
    import org.elasticsearch.rest.RestStatus;
    
    public class IndexDocumentDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
    
        public static void main(String[] args) {
            //这里和RESTful风格不同
            try (TransportClient client = InitDemo.getClient();) {
                // 1、创建索引请求
                IndexRequest request = new IndexRequest(
                        "mess",   //索引
                        "_doc",     // mapping type
                        "11");     //文档id  
                
                // 2、准备文档数据
                // 方式一:直接给JSON串
                String jsonString = "{" +
                        ""user":"kimchy"," +
                        ""postDate":"2013-01-30"," +
                        ""message":"trying out Elasticsearch"" +
                        "}";
                request.source(jsonString, XContentType.JSON); 
                
                // 方式二:以map对象来表示文档
                /*
                Map<String, Object> jsonMap = new HashMap<>();
                jsonMap.put("user", "kimchy");
                jsonMap.put("postDate", new Date());
                jsonMap.put("message", "trying out Elasticsearch");
                request.source(jsonMap); 
                */
                
                // 方式三:用XContentBuilder来构建文档
                /*
                XContentBuilder builder = XContentFactory.jsonBuilder();
                builder.startObject();
                {
                    builder.field("user", "kimchy");
                    builder.field("postDate", new Date());
                    builder.field("message", "trying out Elasticsearch");
                }
                builder.endObject();
                request.source(builder); 
                */
                
                // 方式四:直接用key-value对给出
                /*
                request.source("user", "kimchy",
                                "postDate", new Date(),
                                "message", "trying out Elasticsearch");
                */
                
                //3、其他的一些可选设置
                /*
                request.routing("routing");  //设置routing值
                request.timeout(TimeValue.timeValueSeconds(1));  //设置主分片等待时长
                request.setRefreshPolicy("wait_for");  //设置重刷新策略
                request.version(2);  //设置版本号
                request.opType(DocWriteRequest.OpType.CREATE);  //操作类别  
                */
                
                //4、发送请求
                IndexResponse indexResponse = null;
                try {
                    //方式一: 用client.index 方法,返回是 ActionFuture<IndexResponse>,再调用get获取响应结果
                    indexResponse = client.index(request).get();
                    
                    //方式二:client提供了一个 prepareIndex方法,内部为我们创建IndexRequest
                    /*IndexResponse indexResponse = client.prepareIndex("mess","_doc","11")
                            .setSource(jsonString, XContentType.JSON)
                            .get();*/
                    
                    //方式三:request + listener
                    //client.index(request, listener);    
                    
                } catch(ElasticsearchException e) {
                    // 捕获,并处理异常
                    //判断是否版本冲突、create但文档已存在冲突
                    if (e.status() == RestStatus.CONFLICT) {
                        logger.error("冲突了,请在此写冲突处理逻辑!
    " + e.getDetailedMessage());
                    }
                    
                    logger.error("索引异常", e);
                }catch (InterruptedException | ExecutionException e) {
                    logger.error("索引异常", e);
                }
                
                
                
                
                //5、处理响应
                if(indexResponse != null) {
                    String index = indexResponse.getIndex();
                    String type = indexResponse.getType();
                    String id = indexResponse.getId();
                    long version = indexResponse.getVersion();
                    if (indexResponse.getResult() == DocWriteResponse.Result.CREATED) {
                        System.out.println("新增文档成功,处理逻辑代码写到这里。");
                    } else if (indexResponse.getResult() == DocWriteResponse.Result.UPDATED) {
                        System.out.println("修改文档成功,处理逻辑代码写到这里。");
                    }
                    // 分片处理信息
                    ReplicationResponse.ShardInfo shardInfo = indexResponse.getShardInfo();
                    if (shardInfo.getTotal() != shardInfo.getSuccessful()) {
                        
                    }
                    // 如果有分片副本失败,可以获得失败原因信息
                    if (shardInfo.getFailed() > 0) {
                        for (ReplicationResponse.ShardInfo.Failure failure : shardInfo.getFailures()) {
                            String reason = failure.reason(); 
                            System.out.println("副本失败原因:" + reason);
                        }
                    }
                }
                
                
                //listener 方式
                /*ActionListener<IndexResponse> listener = new ActionListener<IndexResponse>() {
                    @Override
                    public void onResponse(IndexResponse indexResponse) {
                        
                    }
    
                    @Override
                    public void onFailure(Exception e) {
                        
                    }
                };
                client.index(request, listener);
                */
                
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    3. get document 

    获取文档数据
    GetDocumentDemo.java

    package com.study.es_java_client;
    
    import java.io.IOException;
    import java.util.Map;
    import java.util.concurrent.ExecutionException;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.ElasticsearchException;
    import org.elasticsearch.action.get.GetRequest;
    import org.elasticsearch.action.get.GetResponse;
    import org.elasticsearch.client.transport.TransportClient;
    import org.elasticsearch.common.Strings;
    import org.elasticsearch.rest.RestStatus;
    import org.elasticsearch.search.fetch.subphase.FetchSourceContext;
    
    public class GetDocumentDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
    
        public static void main(String[] args) {
            //这里和RESTful风格不同
            try (TransportClient client = InitDemo.getClient();) {
                // 1、创建获取文档请求
                GetRequest request = new GetRequest(
                        "mess",   //索引
                        "_doc",     // mapping type
                        "11");     //文档id  
                
                // 2、可选的设置
                //request.routing("routing");
                //request.version(2);
                
                //request.fetchSourceContext(new FetchSourceContext(false)); //是否获取_source字段
                //选择返回的字段
                String[] includes = new String[]{"message", "*Date"};
                String[] excludes = Strings.EMPTY_ARRAY;
                FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
                request.fetchSourceContext(fetchSourceContext); 
                
                //也可写成这样
                /*String[] includes = Strings.EMPTY_ARRAY;
                String[] excludes = new String[]{"message"};
                FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
                request.fetchSourceContext(fetchSourceContext);*/
                
                
                // 取stored字段
                /*request.storedFields("message"); 
                GetResponse getResponse = client.get(request);
                String message = getResponse.getField("message").getValue();*/
                
                
                //3、发送请求        
                GetResponse getResponse = null;
                try {
                    getResponse = client.get(request).get();
                } catch (ElasticsearchException e) {
                    if (e.status() == RestStatus.NOT_FOUND) {
                        logger.error("没有找到该id的文档" );
                    }
                    if (e.status() == RestStatus.CONFLICT) {
                        logger.error("获取时版本冲突了,请在此写冲突处理逻辑!" );
                    }
                    logger.error("获取文档异常", e);
                }catch (InterruptedException | ExecutionException e) {
                    logger.error("索引异常", e);
                }
                
                //4、处理响应
                if(getResponse != null) {
                    String index = getResponse.getIndex();
                    String type = getResponse.getType();
                    String id = getResponse.getId();
                    if (getResponse.isExists()) { // 文档存在
                        long version = getResponse.getVersion();
                        String sourceAsString = getResponse.getSourceAsString(); //结果取成 String       
                        Map<String, Object> sourceAsMap = getResponse.getSourceAsMap();  // 结果取成Map
                        byte[] sourceAsBytes = getResponse.getSourceAsBytes();    //结果取成字节数组
                        
                        logger.info("index:" + index + "  type:" + type + "  id:" + id);
                        logger.info(sourceAsString);
                        
                    } else {
                        logger.error("没有找到该id的文档" );
                    }
                }
                
                
                //异步方式发送获取文档请求
                /*
                ActionListener<GetResponse> listener = new ActionListener<GetResponse>() {
                    @Override
                    public void onResponse(GetResponse getResponse) {
                        
                    }
                
                    @Override
                    public void onFailure(Exception e) {
                        
                    }
                };
                client.getAsync(request, listener);
                */
                
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    4. Bulk

    批量索引文档,即批量往索引里面放入文档数据.类似于数据库里面批量向表里面插入多行数据,一行数据就是一个文档
    BulkDemo.java

    package com.study.es_java_client;
    
    import java.io.IOException;
    import java.util.concurrent.ExecutionException;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.action.DocWriteRequest;
    import org.elasticsearch.action.DocWriteResponse;
    import org.elasticsearch.action.bulk.BulkItemResponse;
    import org.elasticsearch.action.bulk.BulkRequest;
    import org.elasticsearch.action.bulk.BulkResponse;
    import org.elasticsearch.action.delete.DeleteResponse;
    import org.elasticsearch.action.index.IndexRequest;
    import org.elasticsearch.action.index.IndexResponse;
    import org.elasticsearch.action.update.UpdateResponse;
    import org.elasticsearch.client.transport.TransportClient;
    import org.elasticsearch.common.xcontent.XContentType;
    
    public class BulkDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
    
        public static void main(String[] args) {
            //这里和RESTful风格不同
            try (TransportClient client = InitDemo.getClient();) {
                
                // 1、创建批量操作请求
                BulkRequest request = new BulkRequest(); 
                request.add(new IndexRequest("mess", "_doc", "1")  
                        .source(XContentType.JSON,"field", "foo"));
                request.add(new IndexRequest("mess", "_doc", "2")  
                        .source(XContentType.JSON,"field", "bar"));
                request.add(new IndexRequest("mess", "_doc", "3")  
                        .source(XContentType.JSON,"field", "baz"));
                
                /*
                request.add(new DeleteRequest("mess", "_doc", "3")); 
                request.add(new UpdateRequest("mess", "_doc", "2") 
                        .doc(XContentType.JSON,"other", "test"));
                request.add(new IndexRequest("mess", "_doc", "4")  
                        .source(XContentType.JSON,"field", "baz"));
                */
                
                // 2、可选的设置
                /*
                request.timeout("2m");
                request.setRefreshPolicy("wait_for");  
                request.waitForActiveShards(2);
                */
                
                
                //3、发送请求        
            
                // 同步请求
                BulkResponse bulkResponse = client.bulk(request).get();
                
                
                //4、处理响应
                if(bulkResponse != null) {
                    for (BulkItemResponse bulkItemResponse : bulkResponse) { 
                        DocWriteResponse itemResponse = bulkItemResponse.getResponse(); 
    
                        if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.INDEX
                                || bulkItemResponse.getOpType() == DocWriteRequest.OpType.CREATE) { 
                            IndexResponse indexResponse = (IndexResponse) itemResponse;
                            //TODO 新增成功的处理
    
                        } else if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.UPDATE) { 
                            UpdateResponse updateResponse = (UpdateResponse) itemResponse;
                           //TODO 修改成功的处理
    
                        } else if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.DELETE) { 
                            DeleteResponse deleteResponse = (DeleteResponse) itemResponse;
                            //TODO 删除成功的处理
                        }
                    }
                }
                
                
                //异步方式发送批量操作请求
                /*
                ActionListener<BulkResponse> listener = new ActionListener<BulkResponse>() {
                    @Override
                    public void onResponse(BulkResponse bulkResponse) {
                        
                    }
                
                    @Override
                    public void onFailure(Exception e) {
                        
                    }
                };
                client.bulkAsync(request, listener);
                */
                
            } catch (IOException | InterruptedException | ExecutionException e) {
                e.printStackTrace();
            }
        }
    }

    5. search

    搜索数据
    SearchDemo.java

    package com.study.es_java_client;
    
    import java.io.IOException;
    import java.util.Map;
    import java.util.concurrent.ExecutionException;
    import java.util.concurrent.TimeUnit;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.action.search.SearchRequest;
    import org.elasticsearch.action.search.SearchResponse;
    import org.elasticsearch.action.search.ShardSearchFailure;
    import org.elasticsearch.client.transport.TransportClient;
    import org.elasticsearch.common.unit.TimeValue;
    import org.elasticsearch.index.query.QueryBuilders;
    import org.elasticsearch.rest.RestStatus;
    import org.elasticsearch.search.SearchHit;
    import org.elasticsearch.search.SearchHits;
    import org.elasticsearch.search.builder.SearchSourceBuilder;
    
    public class SearchDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
    
        public static void main(String[] args) {
            try (TransportClient client = InitDemo.getClient();) {
                
                // 1、创建search请求
                //SearchRequest searchRequest = new SearchRequest();
                SearchRequest searchRequest = new SearchRequest("bank"); 
                searchRequest.types("_doc");
                
                // 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法,构造各种查询的方法都在这。
                SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
                
                //构造QueryBuilder
                /*QueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("user", "kimchy")
                        .fuzziness(Fuzziness.AUTO)
                        .prefixLength(3)
                        .maxExpansions(10);
                sourceBuilder.query(matchQueryBuilder);*/
                
                sourceBuilder.query(QueryBuilders.termQuery("age", 24)); 
                sourceBuilder.from(0); 
                sourceBuilder.size(10); 
                sourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS)); 
                
                //是否返回_source字段
                //sourceBuilder.fetchSource(false);
                
                //设置返回哪些字段
                /*String[] includeFields = new String[] {"title", "user", "innerObject.*"};
                String[] excludeFields = new String[] {"_type"};
                sourceBuilder.fetchSource(includeFields, excludeFields);*/
                
                //指定排序
                //sourceBuilder.sort(new ScoreSortBuilder().order(SortOrder.DESC)); 
                //sourceBuilder.sort(new FieldSortBuilder("_uid").order(SortOrder.ASC));
                
                // 设置返回 profile 
                //sourceBuilder.profile(true);
                
                //将请求体加入到请求中
                searchRequest.source(sourceBuilder);
                
                // 可选的设置
                //searchRequest.routing("routing");
                
                // 高亮设置
                /*
                HighlightBuilder highlightBuilder = new HighlightBuilder(); 
                HighlightBuilder.Field highlightTitle =
                        new HighlightBuilder.Field("title"); 
                highlightTitle.highlighterType("unified");  
                highlightBuilder.field(highlightTitle);  
                HighlightBuilder.Field highlightUser = new HighlightBuilder.Field("user");
                highlightBuilder.field(highlightUser);
                sourceBuilder.highlighter(highlightBuilder);*/
                
                
                //加入聚合
                /*TermsAggregationBuilder aggregation = AggregationBuilders.terms("by_company")
                        .field("company.keyword");
                aggregation.subAggregation(AggregationBuilders.avg("average_age")
                        .field("age"));
                sourceBuilder.aggregation(aggregation);*/
                
                //做查询建议
                /*SuggestionBuilder termSuggestionBuilder =
                        SuggestBuilders.termSuggestion("user").text("kmichy"); 
                    SuggestBuilder suggestBuilder = new SuggestBuilder();
                    suggestBuilder.addSuggestion("suggest_user", termSuggestionBuilder); 
                sourceBuilder.suggest(suggestBuilder);*/
                
                //3、发送请求        
                SearchResponse searchResponse = client.search(searchRequest).get();
                
                
                //4、处理响应
                //搜索结果状态信息
                RestStatus status = searchResponse.status();
                TimeValue took = searchResponse.getTook();
                Boolean terminatedEarly = searchResponse.isTerminatedEarly();
                boolean timedOut = searchResponse.isTimedOut();
                
                //分片搜索情况
                int totalShards = searchResponse.getTotalShards();
                int successfulShards = searchResponse.getSuccessfulShards();
                int failedShards = searchResponse.getFailedShards();
                for (ShardSearchFailure failure : searchResponse.getShardFailures()) {
                    // failures should be handled here
                }
                
                //处理搜索命中文档结果
                SearchHits hits = searchResponse.getHits();
                
                long totalHits = hits.getTotalHits();
                float maxScore = hits.getMaxScore();
                
                SearchHit[] searchHits = hits.getHits();
                for (SearchHit hit : searchHits) {
                    // do something with the SearchHit
                    
                    String index = hit.getIndex();
                    String type = hit.getType();
                    String id = hit.getId();
                    float score = hit.getScore();
                    
                    //取_source字段值
                    String sourceAsString = hit.getSourceAsString(); //取成json串
                    Map<String, Object> sourceAsMap = hit.getSourceAsMap(); // 取成map对象
                    //从map中取字段值
                    /*
                    String documentTitle = (String) sourceAsMap.get("title"); 
                    List<Object> users = (List<Object>) sourceAsMap.get("user");
                    Map<String, Object> innerObject = (Map<String, Object>) sourceAsMap.get("innerObject");
                    */
                    logger.info("index:" + index + "  type:" + type + "  id:" + id);
                    logger.info(sourceAsString);
                    
                    //取高亮结果
                    /*Map<String, HighlightField> highlightFields = hit.getHighlightFields();
                    HighlightField highlight = highlightFields.get("title"); 
                    Text[] fragments = highlight.fragments();  
                    String fragmentString = fragments[0].string();*/
                }
                
                // 获取聚合结果
                /*
                Aggregations aggregations = searchResponse.getAggregations();
                Terms byCompanyAggregation = aggregations.get("by_company"); 
                Bucket elasticBucket = byCompanyAggregation.getBucketByKey("Elastic"); 
                Avg averageAge = elasticBucket.getAggregations().get("average_age"); 
                double avg = averageAge.getValue();
                */
                
                // 获取建议结果
                /*Suggest suggest = searchResponse.getSuggest(); 
                TermSuggestion termSuggestion = suggest.getSuggestion("suggest_user"); 
                for (TermSuggestion.Entry entry : termSuggestion.getEntries()) { 
                    for (TermSuggestion.Entry.Option option : entry) { 
                        String suggestText = option.getText().string();
                    }
                }
                */
                
                //异步方式发送获查询请求
                /*
                ActionListener<SearchResponse> listener = new ActionListener<SearchResponse>() {
                    @Override
                    public void onResponse(SearchResponse getResponse) {
                        //结果获取
                    }
                
                    @Override
                    public void onFailure(Exception e) {
                        //失败处理
                    }
                };
                client.searchAsync(searchRequest, listener); 
                */
                
            } catch (IOException | InterruptedException | ExecutionException e) {
                logger.error(e);
            }
        }
    }
    

    6. highlight 高亮

    HighlightDemo.java

    package com.study.es_java_client;
    
    import java.io.IOException;
    import java.util.Map;
    import java.util.concurrent.ExecutionException;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.action.search.SearchRequest;
    import org.elasticsearch.action.search.SearchResponse;
    import org.elasticsearch.client.transport.TransportClient;
    import org.elasticsearch.common.text.Text;
    import org.elasticsearch.index.query.QueryBuilder;
    import org.elasticsearch.index.query.QueryBuilders;
    import org.elasticsearch.rest.RestStatus;
    import org.elasticsearch.search.SearchHit;
    import org.elasticsearch.search.SearchHits;
    import org.elasticsearch.search.builder.SearchSourceBuilder;
    import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
    import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
    
    public class HighlightDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
    
        public static void main(String[] args) {
            try (TransportClient client = InitDemo.getClient();) {
                
                // 1、创建search请求
                SearchRequest searchRequest = new SearchRequest("hl_test"); 
                
                // 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法,构造各种查询的方法都在这。
                SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
                
                //构造QueryBuilder
                QueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("title", "lucene solr");
                sourceBuilder.query(matchQueryBuilder);
                
                //分页设置
                /*sourceBuilder.from(0); 
                sourceBuilder.size(5); ;*/ 
                
                        
                // 高亮设置
                HighlightBuilder highlightBuilder = new HighlightBuilder(); 
                highlightBuilder.requireFieldMatch(false).field("title").field("content")
                    .preTags("<strong>").postTags("</strong>");
                //不同字段可有不同设置,如不同标签
                /*HighlightBuilder.Field highlightTitle = new HighlightBuilder.Field("title"); 
                highlightTitle.preTags("<strong>").postTags("</strong>");
                highlightBuilder.field(highlightTitle);  
                HighlightBuilder.Field highlightContent = new HighlightBuilder.Field("content");
                highlightContent.preTags("<b>").postTags("</b>");
                highlightBuilder.field(highlightContent).requireFieldMatch(false);*/
                
                sourceBuilder.highlighter(highlightBuilder);
                
                searchRequest.source(sourceBuilder);
                
                //3、发送请求        
                SearchResponse searchResponse = client.search(searchRequest).get();
                
                
                //4、处理响应
                if(RestStatus.OK.equals(searchResponse.status())) {
                    //处理搜索命中文档结果
                    SearchHits hits = searchResponse.getHits();
                    long totalHits = hits.getTotalHits();
                    
                    SearchHit[] searchHits = hits.getHits();
                    for (SearchHit hit : searchHits) {        
                        String index = hit.getIndex();
                        String type = hit.getType();
                        String id = hit.getId();
                        float score = hit.getScore();
                        
                        //取_source字段值
                        //String sourceAsString = hit.getSourceAsString(); //取成json串
                        Map<String, Object> sourceAsMap = hit.getSourceAsMap(); // 取成map对象
                        //从map中取字段值
                        /*String title = (String) sourceAsMap.get("title"); 
                        String content  = (String) sourceAsMap.get("content"); */
                        logger.info("index:" + index + "  type:" + type + "  id:" + id);
                        logger.info("sourceMap : " +  sourceAsMap);
                        //取高亮结果
                        Map<String, HighlightField> highlightFields = hit.getHighlightFields();
                        HighlightField highlight = highlightFields.get("title"); 
                        if(highlight != null) {
                            Text[] fragments = highlight.fragments();  //多值的字段会有多个值
                            if(fragments != null) {
                                String fragmentString = fragments[0].string();
                                logger.info("title highlight : " +  fragmentString);
                                //可用高亮字符串替换上面sourceAsMap中的对应字段返回到上一级调用
                                //sourceAsMap.put("title", fragmentString);
                            }
                        }
                        
                        highlight = highlightFields.get("content"); 
                        if(highlight != null) {
                            Text[] fragments = highlight.fragments();  //多值的字段会有多个值
                            if(fragments != null) {
                                String fragmentString = fragments[0].string();
                                logger.info("content highlight : " +  fragmentString);
                                //可用高亮字符串替换上面sourceAsMap中的对应字段返回到上一级调用
                                //sourceAsMap.put("content", fragmentString);
                            }
                        }
                    }
                }
                
            } catch (IOException | InterruptedException | ExecutionException e) {
                logger.error(e);
            }
        }
    }
    

    7. suggest 查询建议

    SuggestDemo.java

    package com.study.es_java_client;
    
    import java.io.IOException;
    import java.util.concurrent.ExecutionException;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.action.search.SearchRequest;
    import org.elasticsearch.action.search.SearchResponse;
    import org.elasticsearch.client.transport.TransportClient;
    import org.elasticsearch.rest.RestStatus;
    import org.elasticsearch.search.builder.SearchSourceBuilder;
    import org.elasticsearch.search.suggest.Suggest;
    import org.elasticsearch.search.suggest.SuggestBuilder;
    import org.elasticsearch.search.suggest.SuggestBuilders;
    import org.elasticsearch.search.suggest.SuggestionBuilder;
    import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
    import org.elasticsearch.search.suggest.term.TermSuggestion;
    
    public class SuggestDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
        
        //拼写检查
        public static void termSuggest(TransportClient client) {
                
            // 1、创建search请求
            //SearchRequest searchRequest = new SearchRequest();
            SearchRequest searchRequest = new SearchRequest("mess"); 
            
            // 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法,构造各种查询的方法都在这。
            SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
             
            sourceBuilder.size(0); 
            
            //做查询建议        
            //词项建议
            SuggestionBuilder termSuggestionBuilder =
                    SuggestBuilders.termSuggestion("user").text("kmichy"); 
            SuggestBuilder suggestBuilder = new SuggestBuilder();
            suggestBuilder.addSuggestion("suggest_user", termSuggestionBuilder);     
            sourceBuilder.suggest(suggestBuilder);
            
            searchRequest.source(sourceBuilder);    
    
            try{
                //3、发送请求        
                SearchResponse searchResponse = client.search(searchRequest).get();
                
                
                //4、处理响应
                //搜索结果状态信息
                if(RestStatus.OK.equals(searchResponse.status())) {
                    // 获取建议结果
                    Suggest suggest = searchResponse.getSuggest(); 
                    TermSuggestion termSuggestion = suggest.getSuggestion("suggest_user"); 
                    for (TermSuggestion.Entry entry : termSuggestion.getEntries()) { 
                        logger.info("text: " + entry.getText().string());
                        for (TermSuggestion.Entry.Option option : entry) { 
                            String suggestText = option.getText().string();
                            logger.info("   suggest option : " + suggestText);
                        }
                    }
                }
    
            } catch (InterruptedException | ExecutionException e) {
                logger.error(e);
            }
                /*
                  "suggest": {
                    "my-suggestion": [
                      {
                        "text": "tring",
                        "offset": 0,
                        "length": 5,
                        "options": [
                          {
                            "text": "trying",
                            "score": 0.8,
                            "freq": 1
                          }
                        ]
                      },
                      {
                        "text": "out",
                        "offset": 6,
                        "length": 3,
                        "options": []
                      },
                      {
                        "text": "elasticsearch",
                        "offset": 10,
                        "length": 13,
                        "options": []
                      }
                    ]
                  }*/
    
        }
        //自动补全
        public static void completionSuggester(TransportClient client) {
                    
            // 1、创建search请求
            //SearchRequest searchRequest = new SearchRequest();
            SearchRequest searchRequest = new SearchRequest("music"); 
            
            // 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法,构造各种查询的方法都在这。
            SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
             
            sourceBuilder.size(0); 
            
            //做查询建议        
            //自动补全
            /*POST music/_search?pretty
                    {
                        "suggest": {
                            "song-suggest" : {
                                "prefix" : "lucene s", 
                                "completion" : { 
                                    "field" : "suggest" ,
                                    "skip_duplicates": true
                                }
                            }
                        }
                    }*/
    
            SuggestionBuilder termSuggestionBuilder =
                    SuggestBuilders.completionSuggestion("suggest").prefix("lucene s")
                    .skipDuplicates(true); 
            SuggestBuilder suggestBuilder = new SuggestBuilder();
            suggestBuilder.addSuggestion("song-suggest", termSuggestionBuilder);     
            sourceBuilder.suggest(suggestBuilder);
            
            searchRequest.source(sourceBuilder);    
                
            try {
                //3、发送请求        
                SearchResponse searchResponse = client.search(searchRequest).get();
                
                
                //4、处理响应
                //搜索结果状态信息
                if(RestStatus.OK.equals(searchResponse.status())) {
                    // 获取建议结果
                    Suggest suggest = searchResponse.getSuggest(); 
                    CompletionSuggestion termSuggestion = suggest.getSuggestion("song-suggest"); 
                    for (CompletionSuggestion.Entry entry : termSuggestion.getEntries()) { 
                        logger.info("text: " + entry.getText().string());
                        for (CompletionSuggestion.Entry.Option option : entry) { 
                            String suggestText = option.getText().string();
                            logger.info("   suggest option : " + suggestText);
                        }
                    }
                }
    
            } catch (InterruptedException | ExecutionException e) {
                logger.error(e);
            }
        }
    
        public static void main(String[] args) {
            try (TransportClient client = InitDemo.getClient();) {
                termSuggest(client);
                
                logger.info("--------------------------------------");
                
                completionSuggester(client);
            } catch (IOException e) {
                logger.error(e);
            }
        }
    }
    

    8. aggregation 聚合分析

    AggregationDemo.java

    package com.study.es_java_client;
    
    import java.io.IOException;
    import java.util.concurrent.ExecutionException;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.elasticsearch.action.search.SearchRequest;
    import org.elasticsearch.action.search.SearchResponse;
    import org.elasticsearch.client.transport.TransportClient;
    import org.elasticsearch.rest.RestStatus;
    import org.elasticsearch.search.aggregations.AggregationBuilders;
    import org.elasticsearch.search.aggregations.Aggregations;
    import org.elasticsearch.search.aggregations.BucketOrder;
    import org.elasticsearch.search.aggregations.bucket.terms.Terms;
    import org.elasticsearch.search.aggregations.bucket.terms.Terms.Bucket;
    import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
    import org.elasticsearch.search.aggregations.metrics.avg.Avg;
    import org.elasticsearch.search.builder.SearchSourceBuilder;
    
    public class AggregationDemo {
        
        private static Logger logger = LogManager.getRootLogger();  
    
        public static void main(String[] args) {
            try (TransportClient client = InitDemo.getClient();) {
                
                // 1、创建search请求
                //SearchRequest searchRequest = new SearchRequest();
                SearchRequest searchRequest = new SearchRequest("bank"); 
                
                // 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法,构造各种查询的方法都在这。
                SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
                 
                sourceBuilder.size(0); 
    
                //加入聚合
                //字段值项分组聚合
                TermsAggregationBuilder aggregation = AggregationBuilders.terms("by_age")
                        .field("age").order(BucketOrder.aggregation("average_balance", true));
                //计算每组的平均balance指标
                aggregation.subAggregation(AggregationBuilders.avg("average_balance")
                        .field("balance"));
                sourceBuilder.aggregation(aggregation);
                
                searchRequest.source(sourceBuilder);
                
                //3、发送请求        
                SearchResponse searchResponse = client.search(searchRequest).get();
                    
                //4、处理响应
                //搜索结果状态信息
                if(RestStatus.OK.equals(searchResponse.status())) {
                    // 获取聚合结果
                    Aggregations aggregations = searchResponse.getAggregations();
                    Terms byAgeAggregation = aggregations.get("by_age"); 
                    logger.info("aggregation by_age 结果");
                    logger.info("docCountError: " + byAgeAggregation.getDocCountError());
                    logger.info("sumOfOtherDocCounts: " + byAgeAggregation.getSumOfOtherDocCounts());
                    logger.info("------------------------------------");
                    for(Bucket buck : byAgeAggregation.getBuckets()) {
                        logger.info("key: " + buck.getKeyAsNumber());
                        logger.info("docCount: " + buck.getDocCount());
                        //logger.info("docCountError: " + buck.getDocCountError());
                        //取子聚合
                        Avg averageBalance = buck.getAggregations().get("average_balance"); 
    
                        logger.info("average_balance: " + averageBalance.getValue());
                        logger.info("------------------------------------");
                    }
                    //直接用key 来去分组
                    /*Bucket elasticBucket = byCompanyAggregation.getBucketByKey("24"); 
                    Avg averageAge = elasticBucket.getAggregations().get("average_age"); 
                    double avg = averageAge.getValue();*/
                    
                }
                
            } catch (IOException | InterruptedException | ExecutionException e) {
                logger.error(e);
            }
        }
    }
    

     9. 官网文档

    Document API 文档操作API:

    https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.2/java-docs.html

    Search API:

    https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.2/java-search.html

     六、Spring Data Elasticsearch

     ES与Spring集成使用,可以作为了解,个人建议还是使用原生的ES的java客户端

     官网链接:

    https://docs.spring.io/spring-data/elasticsearch/docs/current/reference/html/

    代码库:

    https://github.com/spring-projects/spring-data-elasticsearch

    七、源代码获取地址

    https://github.com/leeSmall/Elasticsearch-Java-client-api

    正因为当初对未来做了太多的憧憬,所以对现在的自己尤其失望。生命中曾经有过的所有灿烂,终究都需要用寂寞来偿还。
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  • 原文地址:https://www.cnblogs.com/candlia/p/11919960.html
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