在Elasticsearch中,为java提供了2种客户端,一种是REST风格的客户端,另一种是Java API的客户端。
REST客户端:
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。
1.构造数据
POST /haoke/house/_bulk
{"index":{"_index":"haoke","_type":"house"}}
{"id":"1001","title":"整租 · 南丹大楼 1居室 7500","price":"7500"}
{"index":{"_index":"haoke","_type":"house"}}
{"id":"1002","title":"陆家嘴板块,精装设计一室一厅,可拎包入住诚意租。","price":"8500"}
{"index":{"_index":"haoke","_type":"house"}}
{"id":"1003","title":"整租 · 健安坊 1居室 4050","price":"7500"}
{"index":{"_index":"haoke","_type":"house"}}
{"id":"1004","title":"整租 · 中凯城市之光+视野开阔+景色秀丽+拎包入住","price":"6500"}
{"index":{"_index":"haoke","_type":"house"}}
{"id":"1005","title":"整租 · 南京西路品质小区 21213三轨交汇 配套齐* 拎包入住","price":"6000"}
{"index":{"_index":"haoke","_type":"house"}}
{"id":"1006","title":"祥康里 简约风格 *南户型 拎包入住 看房随时","price":"7000"}
2.REST低级客户端
创建工程,引入依赖:
<dependencies>
<!-- elasticsearch rest客户端 -->
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-client</artifactId>
<version>6.5.4</version>
</dependency>
<!-- json格式化工具 -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.4</version>
</dependency>
<!-- 单元测试 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
</dependencies>
编写测试用例:
public class ESRestTest {
private static final ObjectMapper MAPPER = new ObjectMapper();
private RestClient restClient;
@Before
public void init() {
RestClientBuilder restClientBuilder = RestClient.builder(
new HttpHost("192.168.43.182", 9200, "http"),
new HttpHost("192.168.43.182", 9201, "http"),
new HttpHost("192.168.43.182", 9202, "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"); // 格式化json数据
Response response = this.restClient.performRequest(request);
System.out.println(response.getStatusLine()); // 状态行
System.out.println(EntityUtils.toString(response.getEntity())); // 响应体
}
// 新增数据
@Test
public void testCreateData() throws IOException {
Request request = new Request("POST", "/haoke/house");
Map<String, Object> 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/at6XFXEBO18vQ71rkF2P");
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()));
}
}
从使用中,可以看出,基本和我们使用RESTful api使用几乎是一致的。
3.REST高级客户端
引入依赖:
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>6.5.4</version>
</dependency>
编写测试用例:
public class RestHighLevelTest {
private RestHighLevelClient client;
@Before
public void init() {
RestClientBuilder restClientBuilder = RestClient.builder(
new HttpHost("192.168.43.182", 9200, "http"),
new HttpHost("192.168.43.182", 9201, "http"),
new HttpHost("192.168.43.182", 9202, "http"));
restClientBuilder.setFailureListener(new RestClient.FailureListener() {
@Override
public void onFailure(Node node) {
System.out.println("出错了 -> " + node);
}
});
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<String, Object> 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<String, Object> 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<IndexResponse>() {
@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);
}
/**
* 根据id查询数据
*
* @throws Exception
*/
@Test
public void testQuery() throws Exception {
GetRequest getRequest = new GetRequest("haoke", "house", "bd7GFXEBO18vQ71roF3y");
// 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", "bd7GFXEBO18vQ71roF3y");
// 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", "bd7GFXEBO18vQ71roF3y");
DeleteResponse response = this.client.delete(deleteRequest, RequestOptions.DEFAULT);
System.out.println(response.status());// OK 或者 NOT_FOUND
}
/**
* 更新数据
*
* @throws Exception
*/
@Test
public void testUpdate() throws Exception {
UpdateRequest updateRequest = new UpdateRequest("haoke", "house", "at6XFXEBO18vQ71rkF2P");
Map<String, Object> 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());
}
/**
* 全文搜索
*
* @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"));
// 设置分页
sourceBuilder.from(0);
sourceBuilder.size(5);
// 设置搜索的超时时间
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());
}
}
}