ElasticSearch JavaApi

1、SpringBoot整合ES

①搭建SpringBoot工程

②引入ElasticSearch相关坐标

        
            org.elasticsearch.client
            elasticsearch-rest-high-level-client
            7.4.0
        
        
            org.elasticsearch.client
            elasticsearch-rest-client
            7.4.0
        
        
            org.elasticsearch
            elasticsearch
            7.4.0
        

创建application.yml（方便读取IP与端口号）

elasticsearch:
  host: IP地址
  port: 9200

③测试

ElasticSearchConfig

@Configuration
@ConfigurationProperties(prefix="elasticsearch") // 这个注解通过前缀名获取到yml中的数据
public class ElasticSearchConfig {

    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")
        ));
    }
}

ElasticsearchDay01ApplicationTests

注意：使用@Autowired注入RestHighLevelClient 如果报红线，则是因为配置类所在的包和测试类所在的包，包名不一致造成的2、

@SpringBootTest
class ElasticsearchDay01ApplicationTests {

    @Autowired
    RestHighLevelClient client;

    /**
     * 测试
     */
    @Test
    void contextLoads() {

        System.out.println(client);
    }
}

2、创建索引 2.1、添加索引

/**
     * 添加索引
     * @throws IOException
     */
    @Test
    public void addIndex() throws IOException {
       //1.使用client获取 *** 作索引对象
        IndicesClient indices = client.indices();
        //2.具体 *** 作获取返回值
        //2.1 设置索引名称
        CreateIndexRequest createIndexRequest=new CreateIndexRequest("itheima");

        CreateIndexResponse createIndexResponse = indices.create(createIndexRequest, RequestOptions.DEFAULT);
        //3.根据返回值判断结果
        System.out.println(createIndexResponse.isAcknowledged());
    }

2.2、添加索引，并添加映射

/**
     * 添加索引，并添加映射
     */
    @Test
    public void addIndexAndMapping() throws IOException {
       //1.使用client获取 *** 作索引对象
        IndicesClient indices = client.indices();
        //2.具体 *** 作获取返回值
        //2.具体 *** 作，获取返回值
        CreateIndexRequest createIndexRequest = new CreateIndexRequest("itcast");
        //2.1 设置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);
        //3.根据返回值判断结果
        System.out.println(createIndexResponse.isAcknowledged());
    }

3、查询、删除、判断索引 3.1、查询索引

/**
     * 查询索引
     */
    @Test
    public void queryIndex() throws IOException {
        IndicesClient indices = client.indices();

        GetIndexRequest getRequest=new GetIndexRequest("itcast");
        GetIndexResponse response = indices.get(getRequest, RequestOptions.DEFAULT);
        Map mappings = response.getMappings();
        //iter 提示foreach
        for (String key : mappings.keySet()) {
            System.out.println(key+"==="+mappings.get(key).getSourceAsMap());
        }
    }

3.2、删除索引

 /**
     * 删除索引
     */
    @Test
    public void deleteIndex() throws IOException {
         IndicesClient indices = client.indices();
        DeleteIndexRequest deleteRequest=new DeleteIndexRequest("itheima");
        AcknowledgedResponse delete = indices.delete(deleteRequest, RequestOptions.DEFAULT);
        System.out.println(delete.isAcknowledged());

    }

3.3、索引是否存在

 /**
     * 索引是否存在
     */
    @Test
    public void existIndex() throws IOException {
        IndicesClient indices = client.indices();

        GetIndexRequest getIndexRequest=new GetIndexRequest("itheima");
        boolean exists = indices.exists(getIndexRequest, RequestOptions.DEFAULT);


        System.out.println(exists);

    }

4、添加文档 4.1、添加文档,使用map作为数据

 @Test
    public void addDoc1() throws IOException {
        Map map=new HashMap<>();
        map.put("name","张三");
        map.put("age","18");
        map.put("address","北京二环");
        IndexRequest request=new IndexRequest("itcast").id("1").source(map);
        IndexResponse response = client.index(request, RequestOptions.DEFAULT);
        System.out.println(response.getId());
    }

4.2、添加文档,使用对象作为数据

@Test
public void addDoc2() throws IOException {
    Person person=new Person();
    person.setId("2");
    person.setName("李四");
    person.setAge(20);
    person.setAddress("北京三环");
    String data = JSON.toJSONString(person); // 这里使用了fastjson的方法，所以我们还要导入fastjson依赖包
    IndexRequest request=new IndexRequest("itcast").id(person.getId()).source(data,XContentType.JSON);
    IndexResponse response = client.index(request, RequestOptions.DEFAULT);
    System.out.println(response.getId());
}

5、修改、查询、删除文档 5.1、修改文档：添加文档时，如果id存在则修改，id不存在则添加

/**
     * 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");
        
        //将对象转为json
        String data = JSON.toJSONString(person);

        //1.获取 *** 作文档的对象
        IndexRequest request=new IndexRequest("itcast").id(person.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());
    }

5.2、根据id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());
    }

5.3、根据id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());
    }