Elasticsearch JavaRESTAPI
文章目录
- Java RESTAPI
- Java 低级客户端
- 引入依赖
- 示例代码
- Java 高级客户端
- 引入依赖
- 示例代码
Java RESTAPI
Elasticsearch提供了2种REST客户端，一种是低级客户端，一种是高级客户端。
Java Low Level REST Client：官方提供的低级客户端。该客户端通过http来连接Elasticsearch集群。用户在使用该客户端时需要将请求数据手动拼接成Elasticsearch所需JSON格式进行发送，收到响应时同样也需要将返回的JSON数据手动封装成对象。虽然麻烦，不过该客户端兼容所有的Elasticsearch版本。
Java High Level REST Client：官方提供的高级客户端。该客户端基于低级客户端实现，它提供了很多便捷的API来解决低级客户端需要手动转换数据格式的问题。
Java 低级客户端
引入依赖
org.elasticsearch.client
elasticsearch-rest-client
6.5.4
com.fasterxml.jackson.core
jackson-databind
2.9.4
示例代码
package test.zxm;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.http.HttpHost;
import org.apache.http.util.EntityUtils;
import org.elasticsearch.client.*;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import static org.junit.Assert.assertTrue;
/**
* Unit test for simple App.
*/
public class ESTestLowLevel
{
private static final ObjectMapper MAPPER = new ObjectMapper();
private RestClient restClient;
@Before
public void init() {
RestClientBuilder restClientBuilder = RestClient.builder(
new HttpHost("192.168.12.10", 9200, "http"),
new HttpHost("192.168.12.11", 9200, "http"),
new HttpHost("192.168.12.12", 9200, "http"));
restClientBuilder.setFailureListener(new RestClient.FailureListener() {
@Override
public void onFailure(Node node) {
System.out.println("出错了 -> " + node);
}
});
this.restClient = restClientBuilder.build();
}
@After
public void after() throws IOException {
restClient.close();
}
// 查询集群状态
@Test
public void testGetInfo() throws IOException {
Request request = new Request("GET", "/_cluster/state");
request.addParameter("pretty","true");
Response response = this.restClient.performRequest(request);
System.out.println(response.getStatusLine());
System.out.println(EntityUtils.toString(response.getEntity()));
}
// 新增数据
@Test
public void testCreateData() throws IOException {
Request request = new Request("POST", "/haoke/house");
Map data = new HashMap<>();
data.put("id","2001");
data.put("title","张江高科");
data.put("price","3500");
request.setJsonEntity(MAPPER.writeValueAsString(data));
Response response = this.restClient.performRequest(request);
System.out.println(response.getStatusLine());
System.out.println(EntityUtils.toString(response.getEntity()));
}
// 根据id查询数据
@Test
public void testQueryData() throws IOException {
Request request = new Request("GET", "/haoke/house/G0pfE2gBCKv8opxuRz1y");
Response response = this.restClient.performRequest(request);
System.out.println(response.getStatusLine());
System.out.println(EntityUtils.toString(response.getEntity()));
}
// 搜索数据
@Test
public void testSearchData() throws IOException {
Request request = new Request("POST", "/haoke/house/_search");
String searchJson = "{\"query\": {\"match\": {\"title\": \"拎包入住\"}}}";
request.setJsonEntity(searchJson);
request.addParameter("pretty","true");
Response response = this.restClient.performRequest(request);
System.out.println(response.getStatusLine());
System.out.println(EntityUtils.toString(response.getEntity()));
}
}
Java 高级客户端
引入依赖
org.elasticsearch.client
elasticsearch-rest-high-level-client
6.5.4
示例代码
package test.zxm;
import org.apache.http.HttpHost;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.FetchSourceContext;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;
/**
* Unit test for simple App.
*/
public class ESTestHighLevel
{
private RestHighLevelClient client;
@Before
public void init() {
RestClientBuilder restClientBuilder = RestClient.builder(
new HttpHost("192.168.12.10", 9200, "http"),
new HttpHost("192.168.12.11", 9200, "http"),
new HttpHost("192.168.12.12", 9200, "http"));
this.client = new RestHighLevelClient(restClientBuilder);
}
@After
public void after() throws Exception {
this.client.close();
}
/**
* 新增文档，同步操作
*
* @throws Exception
*/
@Test
public void testCreate() throws Exception {
Map data = new HashMap<>();
data.put("id", "2002");
data.put("title", "南京西路 拎包入住 一室一厅");
data.put("price", "4500");
IndexRequest indexRequest = new IndexRequest("haoke", "house")
.source(data);
IndexResponse indexResponse = this.client.index(indexRequest, RequestOptions.DEFAULT);
System.out.println("id->" + indexResponse.getId());
System.out.println("index->" + indexResponse.getIndex());
System.out.println("type->" + indexResponse.getType());
System.out.println("version->" + indexResponse.getVersion());
System.out.println("result->" + indexResponse.getResult());
System.out.println("shardInfo->" + indexResponse.getShardInfo());
}
/**
* 新增文档，异步操作
*
* @throws Exception
*/
@Test
public void testCreateAsync() throws Exception {
Map data = new HashMap<>();
data.put("id", "2003");
data.put("title", "南京东路 最新房源 二室一厅");
data.put("price", "5500");
IndexRequest indexRequest = new IndexRequest("haoke", "house")
.source(data);
this.client.indexAsync(indexRequest, RequestOptions.DEFAULT, new
ActionListener() {
@Override
public void onResponse(IndexResponse indexResponse) {
System.out.println("id->" + indexResponse.getId());
System.out.println("index->" + indexResponse.getIndex());
System.out.println("type->" + indexResponse.getType());
System.out.println("version->" + indexResponse.getVersion());
System.out.println("result->" + indexResponse.getResult());
System.out.println("shardInfo->" + indexResponse.getShardInfo());
}
@Override
public void onFailure(Exception e) {
System.out.println(e);
}
});
System.out.println("ok");
Thread.sleep(20000);
}
@Test
public void testQuery() throws Exception {
GetRequest getRequest = new GetRequest("haoke", "house",
"GkpdE2gBCKv8opxuOj12");
// 指定返回的字段
String[] includes = new String[]{"title", "id"};
String[] excludes = Strings.EMPTY_ARRAY;
FetchSourceContext fetchSourceContext =
new FetchSourceContext(true, includes, excludes);
getRequest.fetchSourceContext(fetchSourceContext);
GetResponse response = this.client.get(getRequest, RequestOptions.DEFAULT);
System.out.println("数据 -> " + response.getSource());
}
/**
* 判断是否存在
*
* @throws Exception
*/
@Test
public void testExists() throws Exception {
GetRequest getRequest = new GetRequest("haoke", "house",
"GkpdE2gBCKv8opxuOj12");
// 不返回的字段
getRequest.fetchSourceContext(new FetchSourceContext(false));
boolean exists = this.client.exists(getRequest, RequestOptions.DEFAULT);
System.out.println("exists -> " + exists);
}
/**
* 删除数据
*
* @throws Exception
*/
@Test
public void testDelete() throws Exception {
DeleteRequest deleteRequest = new DeleteRequest("haoke", "house",
"GkpdE2gBCKv8opxuOj12");
DeleteResponse response = this.client.delete(deleteRequest,
RequestOptions.DEFAULT);
System.out.println(response.status());// OK or NOT_FOUND
}
/**
* 更新数据
*
* @throws Exception
*/
@Test
public void testUpdate() throws Exception {
UpdateRequest updateRequest = new UpdateRequest("haoke", "house",
"G0pfE2gBCKv8opxuRz1y");
Map data = new HashMap<>();
data.put("title", "张江高科2");
data.put("price", "5000");
updateRequest.doc(data);
UpdateResponse response = this.client.update(updateRequest,
RequestOptions.DEFAULT);
System.out.println("version -> " + response.getVersion());
}
/**
* 测试搜索
*
* @throws Exception
*/
@Test
public void testSearch() throws Exception {
SearchRequest searchRequest = new SearchRequest("haoke");
searchRequest.types("house");
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.query(QueryBuilders.matchQuery("title", "拎包入住"));
sourceBuilder.from(0);
sourceBuilder.size(5);
sourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS));
searchRequest.source(sourceBuilder);
SearchResponse search = this.client.search(searchRequest,
RequestOptions.DEFAULT);
System.out.println("搜索到 " + search.getHits().totalHits + " 条数据.");
SearchHits hits = search.getHits();
for (SearchHit hit : hits) {
System.out.println(hit.getSourceAsString());
}
}
}