Elasticsearch应用的十二个小案例

导入依赖

　　　　　<dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>5.6.8</version>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>transport</artifactId>
            <version>5.6.8</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.58</version>
        </dependency>


        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.8</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.8</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.9.8</version>
        </dependency>

连接所有方法都要用,提成公共方法

public TransportClient getClient() throws UnknownHostException {
        //步骤一：创建一个Settings对象，指定集群名字
        Settings settings = Settings.builder().put("cluster.name", "my-elasticsearch").build();
        //步骤二：创建一个Client连接对象
        TransportClient client = new PreBuiltTransportClient(settings);
        //步骤三：连接到ES服务器
        client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
        client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9301));
        client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9302));
        return client;
    }

　　1.创建一个空的索引库

/**
     * 创建空的索引库
     */
    @Test
    public void createNullIndex() throws UnknownHostException {
        TransportClient client = getClient();
        //创建一个空的索引库  admin()管理权限    indices()索引库   prepareCreate()创建一个索引库   get()执行之前的操作请求
        client.admin().indices().prepareCreate("y2170").get();
        //关闭client对象
        client.close();
    }

        
        2.索引库指定Mapping信息
         

                {
                        "hello":{
                            "properties":{
                                "id":{
                                    "type":"long",
                                    "store":true,
                                    "index":"not_analyzed"
                                },
                                "title":{
                                    "type":"text",
                                    "store":true,
                                    "index":"analyzed",
                                    "analyzer":"ik_max_word"
                                },
                                "content":{
                                    "type":"text",
                                    "store":true,
                                    "index":"analyzed",
                                    "analyzer":"ik_max_word"
                                }
                            }    
                        }
                }

               

/**
                 * 指定索引库的Mapping信息
                 */
                @Test
                public void createMappingByIndex() throws IOException {
                    TransportClient client = getClient();
                    //创建一个XContentBuilder对象，用于拼接JSON格式字符串
                    XContentBuilder xContentBuilder = XContentFactory.jsonBuilder();
                    xContentBuilder.startObject().startObject("hello").startObject("properties")
                            .startObject("id").field("type","long").field("store",true).field("index","not_analyzed").endObject()
                            .startObject("title").field("type","text").field("store",true).field("index","analyzed").field("analyzer","ik_max_word").endObject()
                            .startObject("content").field("type","text").field("store",true).field("index","analyzed").field("analyzer","ik_max_word").endObject()
                            .endObject().endObject().endObject();
                    //指定索引库以及Type类型的Mapping映射信息  preparePutMapping代表向哪一个索引库指定mpiing信息     setType代表该索引库下的TYPE，与上方JSON创建的Type保持一致
                    //setSource 指定JSON字符串的存储对象   get执行
                    client.admin().indices().preparePutMapping("y2170").setType("hello").setSource(xContentBuilder).get();

                    //关闭资源
                    client.close();
                }

        3.创建索引库同时指定Mapping信息

            /**
             * 创建索引库并且指定Mapping信息
             */
            @Test
            public void createIndexAndMapping() throws IOException {
                TransportClient client = getClient();
                //创建索引库
                client.admin().indices().prepareCreate("wdksoft").get();
                //创建Mapping信息
                //创建一个XContentBuilder对象，用于拼接JSON格式字符串
                XContentBuilder xContentBuilder = XContentFactory.jsonBuilder();
                xContentBuilder.startObject().startObject("article").startObject("properties")
                        .startObject("id").field("type","long").field("store",true).field("index","not_analyzed").endObject()
                        .startObject("title").field("type","text").field("store",true).field("index","analyzed").field("analyzer","ik_max_word").endObject()
                        .startObject("content").field("type","text").field("store",true).field("index","analyzed").field("analyzer","ik_max_word").endObject()
                        .endObject().endObject().endObject();


                client.admin().indices().preparePutMapping("wdksoft").setType("article").setSource(xContentBuilder).get();

                //关闭资源
                client.close();
            }

        4.删除索引库
          

 /**
             * 删除索引库
             */
            @Test
            public void deleteIndex() throws UnknownHostException {
                 TransportClient client = getClient();
                 //删除索引库
                 client.admin().indices().prepareDelete("wdksoft").get();

                //关闭资源
                client.close();
            }

        
        
        5.创建文档-通过XContentBuilder对象拼接JSON格式字符串
       (  {  ) 开头用.startObject()

　　(  }  )结尾用.endObject()

　　域用.field(键,值),多个就继续在后面追加

 /**
             * 创建文档-通过XContentBuilder对象拼接JSON字符串
             */
            @Test
            public void createDocumentByXC() throws IOException {
                TransportClient client = getClient();
                //构建文档信息
                XContentBuilder xContentBuilder = XContentFactory.jsonBuilder();
                xContentBuilder.startObject().field("id",1).field("title","Lucene是apache软件基金会4 jakarta项目组的一个子项目")
                        .field("content","Lucene是apache软件基金会4 jakarta项目组的一个子项目，是一个开放源代码的全文检索引擎工具包，但它不是一个完整的全文检索引擎，而是一个全文检索引擎的架构，提供了完整的")
                        .endObject();
                //创建文档
                client.prepareIndex("y2170","hello","1").setSource(xContentBuilder).get();
                client.close();
            }

        
        6.创建文档-通过对象转换为JSON字符串Hello类

public class Hello {
    private Integer id;     //属性要跟Type的域的名字一致
    private String title;
    private String content;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }

    public Hello(Integer id, String title, String content) {
        this.id = id;
        this.title = title;
        this.content = content;
    }

    public Hello() {
    }
}

/**
             * 创建文档-通过对象转换成JSON字符串
             * fastjson  String helloJson = JSON.toJSONString(hello);
             * jackson
             *      ObjectMapper objectMapper=new ObjectMapper();
             *      String helloJson = objectMapper.writeValueAsString(hello);
             */
            @Test
            public void createDocumentByObject() throws UnknownHostException, JsonProcessingException {
                TransportClient client = getClient();

                //准备一个数据（文档）对象
                Hello hello=new Hello(3,"ElasticSearch是一个基于Lucene的搜索服务器","ElasticSearch是一个基于Lucene的搜索服务器。它提供了一个分布式多用户能力的全文搜索引擎，基于RESTful web接口。Elasticsearch是用Java语言开发的，并作为Apache许可条款下的开放源码发布，是一种流行的企业级搜索引擎。ElasticSearch用");
                //将对象转换为JSON格式字符串  fastjson
                /*String helloJson = JSON.toJSONString(hello);
                System.out.println(helloJson);*/

                //利用jackson转换
                ObjectMapper objectMapper=new ObjectMapper();
                String helloJson = objectMapper.writeValueAsString(hello);
                //向索引库中添加文档数据
                client.prepareIndex("y2170","hello","3").setSource(helloJson, XContentType.JSON).get();
                client.close();
            }
   

           
        
        7.删除文档

           /**
             * 删除文档
             */
            @Test
            public void deleteDocument() throws UnknownHostException, JsonProcessingException {
                TransportClient client = getClient();

                //删除文档
                client.prepareDelete("y2170","hello","4").get();

                client.close();
            }

        
        
        8.查询文档-根据文档ID查询
           

/**
             * 根据文档ID进行查询
             */
            @Test
            public void getDocumentByID() throws UnknownHostException, JsonProcessingException {
                TransportClient client = getClient();
                //执行查询,可查询多个
                SearchResponse searchResponse = client.prepareSearch("y2170").setTypes("hello").setQuery(
                        QueryBuilders.idsQuery().addIds("1", "2")
                ).get();
                //获取到查询结果
                SearchHits hits = searchResponse.getHits();
                //如果返回数据较多，默认进行分页，默认10条数据
                System.out.println("获取到文档数据条目数："+hits.getTotalHits());
                //获取到文档数据
                Iterator<SearchHit> iterator = hits.iterator();
                while (iterator.hasNext()){
                    SearchHit hit = iterator.next();
                    System.out.println(hit.getSourceAsString());
                    System.out.println("content:"+hit.getSource().get("content"));
                }

                client.close();
            }

        
        9.查询文档-根据Term关键词查询
          

 /**
             * 根据Term分词进行查询
             */
            @Test
            public void getDocumentByTerm() throws UnknownHostException, JsonProcessingException {
                TransportClient client = getClient();
                //执行查询,可查询多个
                SearchResponse searchResponse = client.prepareSearch("y2170").setTypes("hello").setQuery(
                        QueryBuilders.termQuery("title","服务器")
                ).get();
                //获取到查询结果
                SearchHits hits = searchResponse.getHits();
                //如果返回数据较多，默认进行分页，默认10条数据
                System.out.println("获取到文档数据条目数："+hits.getTotalHits());
                //获取到文档数据
                Iterator<SearchHit> iterator = hits.iterator();
                while (iterator.hasNext()){
                    SearchHit hit = iterator.next();
                    System.out.println(hit.getSourceAsString());
                    System.out.println("content:"+hit.getSource().get("content"));
                }

                client.close();
            }

        
        
        10.查询文档-根据QueryString查询文档
          

 @Test
            public void getDocumentByQueryString() throws UnknownHostException, JsonProcessingException {
                TransportClient client = getClient();
                //执行查询
                SearchResponse searchResponse = client.prepareSearch("y2170").setTypes("hello").setQuery(
                        QueryBuilders.queryStringQuery("Solr是一个独立的企业级搜索应用服务器")
                ).get();
                //获取到查询结果
                SearchHits hits = searchResponse.getHits();
                //如果返回数据较多，默认进行分页，默认10条数据
                System.out.println("获取到文档数据条目数："+hits.getTotalHits());
                //获取到文档数据
                Iterator<SearchHit> iterator = hits.iterator();
                while (iterator.hasNext()){
                    SearchHit hit = iterator.next();
                    System.out.println(hit.getSourceAsString());
                    System.out.println("content:"+hit.getSource().get("content"));
                }

                client.close();
            

        
        11.查询数据的分页检索
            ES当中默认检索数据是10条
          

 /**
             * 分页
             */
            @Test
            public void getDocumentByQueryStringlimit() throws UnknownHostException, JsonProcessingException {
                TransportClient client = getClient();
                //设置查询条件
                SearchRequestBuilder searchRequestBuilder = client.prepareSearch("y2170").setTypes("hello").setQuery(
                        QueryBuilders.queryStringQuery("服务器")
                );
                //加入分页规则       setFrom代表从那一条数据开始获取
                searchRequestBuilder.setFrom(0).setSize(5);
                SearchResponse searchResponse = searchRequestBuilder.get();
                //获取到查询结果
                SearchHits hits = searchResponse.getHits();
                //如果返回数据较多，默认进行分页，默认10条数据
                System.out.println("获取到文档数据条目数：" + hits.getTotalHits());
                //获取到文档数据
                Iterator<SearchHit> iterator = hits.iterator();
                while (iterator.hasNext()) {
                    SearchHit hit = iterator.next();
                    System.out.println(hit.getSourceAsString());
                    System.out.println("content:" + hit.getSource().get("content"));
                }

                client.close();
            }

              12.查询数据的高亮显示执行查询数据之前设置高亮显示规则

                1.设置高亮显示的域
                2.设置高亮显示前缀
                3.设置高亮显示后缀
            执行查询
            获取到高亮显示的数据
          

  /**
                 * 高亮显示
                 */
                @Test
                public void getDocumentByQueryHight() throws UnknownHostException, JsonProcessingException {
                    TransportClient client = getClient();
                    //设置查询条件
                    SearchRequestBuilder searchRequestBuilder = client.prepareSearch("y2170").setTypes("hello").setQuery(
                            QueryBuilders.termQuery("title", "服务器")
                    );
                    //加入分页规则       setFrom代表从那一条数据开始获取
                    searchRequestBuilder.setFrom(0).setSize(5);
                    //设置高亮规则
                    HighlightBuilder highlightBuilder=new HighlightBuilder();
                    //指定高亮显示的域
                    highlightBuilder.field("title");
                    highlightBuilder.preTags("<span style='color:red'>");
                    highlightBuilder.postTags("</span>");
                    searchRequestBuilder.highlighter(highlightBuilder);
                    //执行查询
                    SearchResponse searchResponse = searchRequestBuilder.get();
                    //获取到查询结果
                    SearchHits hits = searchResponse.getHits();
                    //如果返回数据较多，默认进行分页，默认10条数据
                    System.out.println("获取到文档数据条目数：" + hits.getTotalHits());
                    //获取到文档数据
                    Iterator<SearchHit> iterator = hits.iterator();
                    while (iterator.hasNext()) {
                        SearchHit hit = iterator.next();
                        System.out.println(hit.getSourceAsString());
                        /* System.out.println("content:" + hit.getSource().get("content"));*/

                        //获取高亮结果
                        Text[] titles = hit.getHighlightFields().get("title").getFragments();
                        for(Text text:titles){
                            System.out.println("高亮显示数据为："+text);
                        }
                    }

                    client.close();
                }