ElasticSearch Java API

Posted 2022-01-15 Juno3550

目录

• SpringBoot 整合 ES
• 操作索引
  • 创建索引
  • 查询索引
  • 删除索引
• 操作文档
  • 添加文档
  • 修改文档
  • 查询文档
  • 删除文档
• bulk 批量操作

SpringBoot 整合 ES

1）引入 ElasticSearch 相关坐标：

        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>7.4.0</version>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-client</artifactId>
            <version>7.4.0</version>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>7.4.0</version>
        </dependency>

2）ElasticSearchConfig.java（ES 配置类）：

package com.example.es_demo.config;

import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@ConfigurationProperties(prefix = "elasticsearch")
public class EsConfig 

    private String host;
    private int port;

    public String getHost() 
        return host;
    

    public void setHost(String host) 
        this.host = host;
    

    public int getPort() 
        return port;
    

    public void setPort(int port) 
        this.port = port;
    

    @Bean
    public RestHighLevelClient client()
        return new RestHighLevelClient(RestClient.builder(
                new HttpHost(host, port, "http")
        ));
    

3）测试类：

• 注意：使用 @Autowired 注入 RestHighLevelClient 时如果报红线，则是因为配置类所在的包和测试类所在的包，两者包名不一致造成的。

package com.example.es_demo;

import org.elasticsearch.client.RestHighLevelClient;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class EsDemoApplicationTests 

    @Autowired
    RestHighLevelClient client;

    @Test
    void contextLoads() 
        System.out.println(client);
    

操作索引

创建索引

   /**
     * 添加索引
     */
    @Test
    public void addIndex() throws IOException 
        // 1.使用client获取操作索引对象
        IndicesClient indices = client.indices();
        // 2.创建索引
        CreateIndexRequest createIndexRequest = new CreateIndexRequest("index1");
        CreateIndexResponse createIndexResponse = indices.create(createIndexRequest, RequestOptions.DEFAULT);
        // 3.根据返回值判断结果
        System.out.println(createIndexResponse.isAcknowledged());
    

    /**
     * 添加索引，并添加映射
     */
    @Test
    public void addIndexAndMapping() throws IOException 
        // 1.使用client获取操作索引对象
        IndicesClient indices = client.indices();
        // 2.添加索引
        CreateIndexRequest createIndexRequest = new CreateIndexRequest("index2");
        // 3.添加mappings
        String mapping = "\\n" +
                "      \\"properties\\" : \\n" +
                "        \\"address\\" : \\n" +
                "          \\"type\\" : \\"text\\",\\n" +
                "          \\"analyzer\\" : \\"ik_max_word\\"\\n" +
                "        ,\\n" +
                "        \\"age\\" : \\n" +
                "          \\"type\\" : \\"long\\"\\n" +
                "        ,\\n" +
                "        \\"name\\" : \\n" +
                "          \\"type\\" : \\"keyword\\"\\n" +
                "        \\n" +
                "      \\n" +
                "    ";
        createIndexRequest.mapping(mapping, XContentType.JSON);
        CreateIndexResponse createIndexResponse = indices.create(createIndexRequest, RequestOptions.DEFAULT);
        // 4.根据返回值判断结果
        System.out.println(createIndexResponse.isAcknowledged());
    

查询索引

    /**
     * 查询索引
     */
    @Test
    public void queryIndex() throws IOException 
        IndicesClient indices = client.indices();
        GetIndexRequest getRequest=new GetIndexRequest("index2");
        GetIndexResponse response = indices.get(getRequest, RequestOptions.DEFAULT);
        Map<String, MappingMetaData> mappings = response.getMappings();

        for (String key : mappings.keySet()) 
            System.out.println(key+"==="+mappings.get(key).getSourceAsMap());
            // index2===properties=address=analyzer=ik_max_word, type=text, name=type=keyword, age=type=long
        
    

    /**
     * 判断索引是否存在
     */
    @Test
    public void existIndex() throws IOException 
        IndicesClient indices = client.indices();
        GetIndexRequest getIndexRequest=new GetIndexRequest("index1");
        boolean exists = indices.exists(getIndexRequest, RequestOptions.DEFAULT);

        System.out.println(exists);
    

删除索引

    /**
     * 删除索引
     */
    @Test
    public void deleteIndex() throws IOException 
        IndicesClient indices = client.indices();
        DeleteIndexRequest deleteRequest=new DeleteIndexRequest("index2");
        AcknowledgedResponse delete = indices.delete(deleteRequest, RequestOptions.DEFAULT);
        // 返回是否删除成功
        System.out.println(delete.isAcknowledged());
    

操作文档

引入阿里巴巴的 JSON 格式转换库：

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.4</version>
        </dependency>

添加文档

注意：在仅有索引的情况下也可以添加文档，且在有映射的情况下也可以新增字段，两者操作均会自动添加默认类型。

    /**
     * 添加文档，使用map作为数据
     */
    @Test
    public void addDoc() throws IOException 
        // map数据
        Map data = new HashMap();
        data.put("address", "北京昌平");
        data.put("name", "大胖");
        data.put("age", 20);
        // 获取操作文档的对象
        IndexRequest request = new IndexRequest("index2").id("1").source(data);
        // 添加数据，获取结果
        IndexResponse response = client.index(request, RequestOptions.DEFAULT);
        //打印响应结果
        System.out.println(response.getId());
    

    /**
     * 添加文档，使用对象作为数据
     */
    @Test
    public void addDoc2() throws IOException 
        // 对象数据
        Person p = new Person();
        p.setId("3");
        p.setName("小胖3333");
        p.setAge(30);
        p.setAddress("广东深圳");
        p.setHobby("basketball");
        // 将对象转为json
        String data = JSON.toJSONString(p);
        // 获取操作文档的对象
        IndexRequest request = new IndexRequest("index2").id(p.getId()).source(data, XContentType.JSON);
        // 添加数据，获取结果
        IndexResponse response = client.index(request, RequestOptions.DEFAULT);
        // 打印响应结果
        System.out.println(response.getId());

修改文档

    /**
     * 修改文档：添加文档时，如果id存在则修改，id不存在则添加
     */
    @Test
    public void UpdateDoc() throws IOException 
        Person person=new Person();
        person.setId("2");
        person.setName("李四");
        person.setAge(20);
        person.setAddress("北京三环车王");

        String data = JSON.toJSONString(person);

        IndexRequest request=new IndexRequest("itcast").id(person.getId()).source(data,XContentType.JSON);
        IndexResponse response = client.index(request, RequestOptions.DEFAULT);
        System.out.println(response.getId());
    

查询文档

    /**
     * 根据id查询文档
     */
    @Test
    public void getDoc() throws IOException 

        //设置查询的索引、文档
        GetRequest indexRequest=new GetRequest("itcast","2");

        GetResponse response = client.get(indexRequest, RequestOptions.DEFAULT);
        System.out.println(response.getSourceAsString());
    

删除文档

/**
     * 根据id删除文档
     */
    @Test
    public void delDoc() throws IOException 

        //设置要删除的索引、文档
        DeleteRequest deleteRequest=new DeleteRequest("itcast","1");

        DeleteResponse response = client.delete(deleteRequest, RequestOptions.DEFAULT);
        System.out.println(response.getId());
    

bulk 批量操作

    /**
     *  Bulk 批量操作
     */
    @Test
    public void test2() throws IOException 

        // 创建bulkrequest对象，整合所有操作
        BulkRequest bulkRequest =new BulkRequest();

        // 1. 删除5号记录
        DeleteRequest deleteRequest=new DeleteRequest("person1", "5");
        bulkRequest.add(deleteRequest);

        // 2. 添加6号记录
        Map<String, Object> map=new HashMap<>();
        map.put("name", "六号");
        IndexRequest indexRequest=new IndexRequest("person1").id("6").source(map);
        bulkRequest.add(indexRequest);

        // 3. 修改3号记录 名称为 “三号”
        Map<String, Object> mapUpdate=new HashMap<>();
        mapUpdate.put("name", "三号");
        UpdateRequest updateRequest=new UpdateRequest("person1", "3").doc(mapUpdate);
        bulkRequest.add(updateRequest);

        // 执行批量操作
        BulkResponse response = client.bulk(bulkRequest, RequestOptions.DEFAULT);
        System.out.println(response.status());