Elastic Stack：Java客户端连接ElasticSearch

一.pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>elasticsearch</artifactId>
        <groupId>com.wj</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>ESDemo</artifactId>

    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.elasticsearch.client/elasticsearch-rest-high-level-client -->
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>7.7.1</version>
            <exclusions>
                <exclusion>
                    <groupId>org.elasticsearch</groupId>
                    <artifactId>elasticsearch</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.elasticsearch/elasticsearch -->
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>7.7.1</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-test -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <version>2.3.0.RELEASE</version>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
            <version>2.3.0.RELEASE</version>
        </dependency>
    </dependencies>
</project>

 二.基本步骤

public class TestDemo {
    public static void main(String[] args) throws IOException {
        //获取连接客户端
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("192.168.10.138", 9200, "http")));
        //构建请求
        GetRequest request = new GetRequest("book", "1");
        //执行
        GetResponse fields = client.get(request, RequestOptions.DEFAULT);
        //获取结果
        System.out.println(fields.getId());
        System.out.println(fields.getSource());
    }
}

 执行结果：

三.使用springboot测试

配置文件 application.yml：

spring:
  application:
    name: search-service
test:
  elasticsearch:
    address: 192.168.10.138
    port: 9200

 配置类：

@Configuration
public class EsConfig {

    @Value("${test.elasticsearch.address}")
    private String address;

    @Value("${test.elasticsearch.port}")
    private Integer port;

    @Bean(destroyMethod = "close")
    public RestHighLevelClient restHighLevelClient(){
        return new RestHighLevelClient(RestClient.builder(new HttpHost(address, port, "http")));
    }

}

 测试类：

@SpringBootTest(classes = SearchApplication.class)
@RunWith(SpringRunner.class)
public class TestDocument {

    @Qualifier("restHighLevelClient")
    @Autowired
    RestHighLevelClient client;

    @Test
    public void  test() throws IOException, InterruptedException {
        //构建请求
        GetRequest request = new GetRequest("book", "1");
        //设置可选参数
        FetchSourceContext context = new FetchSourceContext(true, new String[]{"name", "price"}, Strings.EMPTY_ARRAY);
        request.fetchSourceContext(context);
        //同步执行
        //GetResponse fields = client.get(request, RequestOptions.DEFAULT);

        //异步执行
        client.getAsync(request, RequestOptions.DEFAULT, new ActionListener<>() {
            //成功时的操作
            @Override
            public void onResponse(GetResponse documentFields) {
                //获取结果
                System.out.println(documentFields.getId());
                System.out.println(documentFields.getSource());
                System.out.println(documentFields.getSourceAsString());
                System.out.println(documentFields.getSourceAsMap());
                System.out.println(new String(documentFields.getSourceAsBytes()));
            }
            //失败的操作
            @Override
            public void onFailure(Exception e) {
                e.printStackTrace();
            }
        });
        Thread.sleep(5000);
    }
}

 查询结果：

四.测试文档新增

构建文档数据的四种方法：

直接使用json字符串构建：

        //构建请求
        IndexRequest request = new IndexRequest("test_add");
        request.id("2");
        //构建文档数据
        //方法1:直接写json字符串
        String jsonStr = "{\n" +
                "    \"name\": \"php\",\n" +
                "    \"description\": \"php是世界上最好的语言\",\n" +
                "    \"studymodel\": \"201002\",\n" +
                "    \"price\":38.6,\n" +
                "    \"timestamp\":\"2019-08-25 19:11:35\",\n" +
                "    \"tags\": [ \"php\", \"开发\"]\n" +
                "}";
        request.source(jsonStr, XContentType.JSON);
        //设置超时时间
        request.timeout(TimeValue.timeValueSeconds(2L));
        //手动维护版本号
        request.version(2);
        request.versionType(VersionType.EXTERNAL);
        //执行
        IndexResponse indexResponse = client.index(request, RequestOptions.DEFAULT);
        System.out.println(indexResponse.getIndex());
        System.out.println(indexResponse.getId());
        System.out.println(indexResponse.getResult());

 运行结果：

 使用map构建：

        Map<String, Object> map = new HashMap<>();
        map.put("user","john");
        map.put("age","18");
        map.put("time","2020-12-12");
        request.source(map);

 使用XContentBuilder构建：

XContentBuilder builder = XContentFactory.jsonBuilder().startObject();
        {
            builder.field("user","john");
            builder.field("age",18);
            builder.timeField("time","2020-12-12");
        }
        builder.endObject();
        request.source(builder);

 直接在request中构建：

request.source("user","john").source("age","18").source("time","2020-12-12");

 异步：

        Cancellable cancellable = client.indexAsync(request, RequestOptions.DEFAULT, new ActionListener<>() {
            @Override
            public void onResponse(IndexResponse indexResponse) {
                System.out.println(indexResponse.getIndex());
                System.out.println(indexResponse.getId());
                System.out.println(indexResponse.getResult());
            }

            @Override
            public void onFailure(Exception e) {
                e.printStackTrace();
            }
        });

 也可以进行更新操作：

       //构建请求
        IndexRequest request = new IndexRequest("test_add");
        request.id("4");
        //构建文档数据
        Map<String, Object> map = new HashMap<>();
        map.put("user","john");
        map.put("age","19");
        map.put("time","2020-12-12");
        request.source(map);
        //设置超时时间
        request.timeout(TimeValue.timeValueSeconds(2L));
        //手动维护版本号
        request.version(3);
        request.versionType(VersionType.EXTERNAL);
        //执行
        //IndexResponse indexResponse = client.index(request, RequestOptions.DEFAULT);
        Cancellable cancellable = client.indexAsync(request, RequestOptions.DEFAULT, new ActionListener<>() {
            @Override
            public void onResponse(IndexResponse indexResponse) {
                System.out.println(indexResponse.getIndex());
                System.out.println(indexResponse.getId());
                System.out.println(indexResponse.getResult());
                if(indexResponse.getResult()== DocWriteResponse.Result.CREATED){
                    DocWriteResponse.Result result = indexResponse.getResult();
                    System.out.println(result);
                }else if(indexResponse.getResult()== DocWriteResponse.Result.UPDATED){
                    DocWriteResponse.Result result = indexResponse.getResult();
                    System.out.println(result);
                }
            }

            @Override
            public void onFailure(Exception e) {
                e.printStackTrace();
            }
        });
        Thread.sleep(5000);

对结果进行监控：

                ReplicationResponse.ShardInfo shardInfo = indexResponse.getShardInfo();
                if(shardInfo.getTotal()!=shardInfo.getSuccessful()){
                    System.out.println(shardInfo.getSuccessful());
                    System.out.println(shardInfo.getTotal());
                    System.out.println("处理成功的分片少于总分片");
                }
                if(shardInfo.getFailed()>0){
                    for (ReplicationResponse.ShardInfo.Failure failure : shardInfo.getFailures()) {
                        System.out.println(failure.reason());
                    }
                }

 五.测试修改：

        //创建请求
        UpdateRequest request = new UpdateRequest("test_add","3");
        Map<String, Object> map = new HashMap<>();
        map.put("age","33");
        request.doc(map);
        //设置重试次数
        request.retryOnConflict(4);
        //执行
        UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
        //获取结果
        System.out.println(response.getId());
        System.out.println(response.getResult());

 六.测试删除

        DeleteRequest request = new DeleteRequest("test_add", "3");
        DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);
        System.out.println(response.getId());
        System.out.println(response.getResult());

 七.测试bulk批量操作

        BulkRequest request = new BulkRequest();
        request.add(new IndexRequest("test_add").id("6").source(XContentType.JSON,"address","3"));
        request.add(new DeleteRequest("test_add").id("4"));
        BulkResponse responses = client.bulk(request, RequestOptions.DEFAULT);
        for (BulkItemResponse respons : responses) {
            DocWriteResponse response = respons.getResponse();
            switch (respons.getOpType()){
                case INDEX:
                    System.out.println(response);
                case DELETE:
                    System.out.println(response);
            }
        }