springboot整合ES

ES提供的Java客户端——RestClient

RestClient是官方推荐使用的，它包括两种：Java Low Level REST Client和 Java High Level REST Client。ES在6.0之后提供 Java High Level REST Client， 两种客户端官方更推荐使用 Java High Level REST Client，不过当前它还处于完善中，有些功能还没有（如果它有不支持的功能，则使用Java Low Level REST Client。）。

增加es依赖

<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-high-level-client</artifactId>
    <version>6.2.1</version>
</dependency>
<dependency>
    <groupId>org.elasticsearch</groupId>
    <artifactId>elasticsearch</artifactId>
    <version>6.2.1</version>
</dependency>

这两个依赖会存在问题
java.lang.NoSuchMethodError: org.elasticsearch.client.Request.<init>(Ljava/lang/String;Ljava/lang/String

可以通过更改版本来解决,原因是两个jar包中都有Request这个类,包名和项目名还是一样的,根据双亲委派加载类机制,这时high-level-client中的就不会加载,(同包名和项目名的类在不通jar中只加载一个)

<dependency>
	<groupId>org.elasticsearch.client</groupId>
		<artifactId>elasticsearch-rest-high-level-client</artifactId>
		<version>6.5.4</version>
	</dependency>
<dependency>
	groupId>org.elasticsearch</groupId>
	<artifactId>elasticsearch</artifactId>
	<version>6.4.3</version>
</dependency>

配置文件

server:
  port: ${port:40100}
spring:
  application:
    name: xc-service-search
xuecheng:	#自定义属性项
  elasticsearch:
    host-list: ${eshostlist:127.0.0.1:9200} #多个节点中间用逗号分隔

ES配置类

**
 * ElasticsearchConfig class
 *
 * @author : xwx
 * @date : 2019/6/20
 */
@Configuration
public class ElasticsearchConfig {

    @Value("${xuwenxiang.elasticsearch.host-list}")
    private String hostList;

    @Bean
    public RestHighLevelClient restHighLevelClient() {
        return new RestHighLevelClient(RestClient.builder(getHttpHostList(hostList)));
    }

    private HttpHost[] getHttpHostList(String hostList) {
        String[] hosts = hostList.split(",");
        HttpHost[] httpHostArr = new HttpHost[hosts.length];
        for (int i = 0; i < hosts.length; i++) {
            String[] items = hosts[i].split(":");
            httpHostArr[i] = new HttpHost(items[0], Integer.parseInt(items[1]), "http");
        }
        return httpHostArr;
    }

    // rest low level client
    @Bean
    public RestClient restClient() {
        return RestClient.builder(getHttpHostList(hostList)).build();
    }
}

 

客户端写法
TransportClient:elastic计划在Elasticsearch 7.0中弃用TransportClient，并在8.0中完全删除它
RestHighLevelClient:8.0以后Java高级REST客户端，它执行HTTP请求而不是序列化的Java请求

Java客户端主要用途有:
　　(1)在现有集群上执行标准索引，获取，删除和搜索操作
　　(2)在正在运行的集群上执行管理任务

• 修改时如果该文档不存在会报错
• 删除时如果该文档不存在不会报错

TransportClient
新建索引库

/**
 * TestES class
 *
 * @author : xwx
 * @date : 2019/6/20
 */
@SpringBootTest
@RunWith(SpringRunner.class)
public class TestESRestClient {

    @Autowired
    RestHighLevelClient restHighLevelClient;    //ES连接对象

    @Autowired
    RestClient restClient;

    /**
     * 新建索引库
     *
     * @throws IOException
     */
    @Test
    public void CreateIndex() throws IOException {
        CreateIndexRequest request = new CreateIndexRequest("index_xuwenxiang_test");
        request.settings(Settings.builder().put("number_of_shards", 1).put("number_of_replicas", 0));
        //通过ES连接对象获取索引库管理对象
        IndicesClient indicesClient = restHighLevelClient.indices();
        CreateIndexResponse response=indicesClient.create(request);
        System.out.print(response);

    }
}

新建映射mapping

    TransportClient client = new PreBuiltTransportClient(Settings.EMPTY)
                .addTransportAddress(new TransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
        XContentBuilder mapping = XContentFactory.jsonBuilder().startObject().startObject("properties")
                .startObject("test").field("type","text").endObject()
                .startObject("title").field("type","text").endObject()
                .endObject().endObject();
        PutMappingRequest request= Requests.putMappingRequest("index_xuwenxiang_test").type("doc").source(mapping);
        client.admin().indices().putMapping(request).actionGet();

新增文档

    /**
     * 新增文档
     *
     * @throws IOException
     */
    @Test
    public void insertDoc() throws IOException {
        Map<String ,Object> jsonMap=new HashMap<>();
        jsonMap.put("test","测试测试测试4");
        jsonMap.put("title","标题标题标题4");
        IndexRequest request=new IndexRequest("index_xuwenxiang_old_create","doc","4").source(jsonMap);
        client.prepareIndex("index_xuwenxiang_old_create","doc","4").setSource(jsonMap).execute().actionGet();
    }

查询文档

   /**
     * 查询
     * @throws IOException
     */
    @Test
    public  void  getDoc()throws  IOException{
        GetResponse getResponse =client.prepareGet("index_xuwenxiang_old_create","doc","4").get();
        System.out.print(getResponse);
    }

修改文档

/**
     * 修改
     *
     * @throws IOException
     */
    @Test
    public void update() throws IOException {
        UpdateRequest updateRequest=new UpdateRequest("index_xuwenxiang_old_create","doc","4");
        Map<String, Object> docMap = new HashMap<>();
        docMap.put("test", "update测试测试测试4_old");
        docMap.put("title", "update测试测试测试4_old");
        updateRequest.doc(docMap);
        UpdateResponse response = client.update(updateRequest).actionGet();
        System.out.println(response);
    }

删除文档

/**
     * 删除
     *
     * @throws IOException
     */
    @Test
    public void delete() throws IOException {
        DeleteRequest request = new DeleteRequest("index_xuwenxiang_old_create", "doc", "4");
        DeleteResponse response = client.delete(request).actionGet();
        System.out.println(response);
    }

RestHighLevelClient
新建索引库

 /**
     * 新建索引库
     *
     * @throws IOException
     */
    @Test
    public void createIndex() throws IOException {
        CreateIndexRequest request = new CreateIndexRequest("index_xuwenxiang_test_new");
        request.settings(Settings.builder().put("number_of_shards", 1).put("number_of_replicas", 0));
        //通过ES连接对象获取索引库管理对象
        IndicesClient indicesClient = restHighLevelClient.indices();
        CreateIndexResponse response = indicesClient.create(request);
        System.out.print(response);

    }

新建映射mapping

/**
     * 新建索引mapping
     *
     * @throws IOException
     */
    @Test
    public void createMapping() throws IOException {
        IndexRequest indexRequest=new IndexRequest();

        XContentBuilder builder= JsonXContent.contentBuilder()
                .startObject()
                    .startObject("properties")
                        .startObject("title")
                            .field("type","text")
                            .field("analyzer","ik_max_word")
                        .endObject()
                        .startObject("content")
                            .field("type","text")
                            .field("analyzer","ik_max_word")
                        .endObject()
                    .endObject()
                .endObject();
        indexRequest.source(builder);
        // 生成json字符串
        String source = indexRequest.source().utf8ToString();
        HttpEntity entity = new NStringEntity(source, ContentType.APPLICATION_JSON);
        // 使用RestClient进行操作 而非rhlClient
        Response response = restClient.performRequest("post", "/index_xuwenxiang_test_new_one/doc/_mapping", Collections.<String, String> emptyMap(),
                entity);
        System.out.println(response);

    }

新增文档

/**
     * 新增文档方式一
     *
     * @throws IOException
     */
    @Test
    public void insertDocOne() throws IOException {
        Map<String ,Object> jsonMap=new HashMap<>();
        jsonMap.put("test","测试测试测试");
        jsonMap.put("title","标题标题标题");
        IndexRequest request=new IndexRequest().source(jsonMap);
        // 生成json字符串
        String source = request.source().utf8ToString();
        HttpEntity entity = new NStringEntity(source, ContentType.APPLICATION_JSON);
        restClient.performRequest("post","/index_xuwenxiang_old_create/doc/1", Collections.emptyMap(),entity);
    }
    /**
     * 新增文档方式二
     *
     * @throws IOException
     */
    @Test
    public void insertDocMethodTwo() throws IOException {
        Map<String ,Object> jsonMap=new HashMap<>();
        jsonMap.put("test","测试测试测试2");
        jsonMap.put("title","标题标题标题2");
        IndexRequest request=new IndexRequest("index_xuwenxiang_old_create","doc","2").source(jsonMap);
        restHighLevelClient.index(request);
    }

修改文档

 /**
     * 修改
     *
     * @throws IOException
     */
    @Test
    public void update() throws IOException {
        UpdateRequest updateRequest=new UpdateRequest("index_xuwenxiang_old_create","doc","4");
        Map<String, Object> docMap = new HashMap<>();
        docMap.put("test", "update测试测试测试4");
        docMap.put("title", "update测试测试测试4");
        updateRequest.doc(docMap);
        UpdateResponse response = restHighLevelClient.update(updateRequest);
        System.out.println(response);
    }

删除文档

 /**
     * 删除
     *
     * @throws IOException
     */
    @Test
    public void delete() throws IOException {
        DeleteRequest request = new DeleteRequest("index_xuwenxiang_old_create", "doc", "4");
        DeleteResponse response = restHighLevelClient.delete(request);
        System.out.println(response);
    }

踩过的坑

• 用XContentFactory.jsonBuilder的时候如果field用一个参数就会报错

 XContentBuilder mapping = XContentFactory.jsonBuilder().startObject().startObject("properties")
                .startObject("test").field("text").endObject()
                .startObject("title").field("text").endObject()
                .endObject().endObject();

​​
这是构建出来的json,这里注意这个json是不能解析的
{"properties":{"test":{"text"},"title":{"text"}}}

​
报错:ElasticsearchParseException[Failed to parse content to map
]; nested: IOException[Unexpected character ('}' (code 125)): was expecting a colon to separate field name and value

• 索引必须存在

• Requests.putMappingRequest("index_xuwenxiang_testfff")
• 如果不存在就会报错:no such index