ElasticSearch的简单java Api
1． Java 简单api
1.1 es技术特点
1es技术比较特殊，不像其他分布式、大数据课程，haddop、spark、hbase。es代码层面很好写，难的是概念的理解。
2es最重要的是他的rest api。跨语言的。在真实生产中，探查数据、分析数据，使用rest更方便。
3本课程将会大量讲解内部原理及rest api。java代码会在重要的api后学习。
1.2 java 客户端简单获取数据
java api 文档 https://www.elastic.co/guide/en/elasticsearch/client/java-rest/1.3/java-rest-overview.html
low : 偏向底层。
high：高级封装。足够。
1导包
<!--es客户端-->
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>7.4.2</version>
<exclusions>
<exclusion>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
</exclusion>
<exclusion>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-client</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-client</artifactId>
<version>7.4.2</version>
</dependency>
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>7.4.2</version>
</dependency>
2代码
步骤
1 获取连接客户端
2构建请求
3执行
4获取结果
//获取连接客户端
RestHighLevelClient client = new RestHighLevelClient(
RestClient.builder(
new HttpHost("192.168.1.106", 9200, "http")));
//构建请求
GetRequest getRequest = new GetRequest("book", "1");
// 执行
GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);
// 获取结果
if (getResponse.isExists()) {
long version = getResponse.getVersion();
String sourceAsString = getResponse.getSourceAsString();//检索文档(String形式)
System.out.println(sourceAsString);
}
1.3 结合spring-boot-test测试文档查询
0为什么使用spring boot test
- 当今趋势
- 方便开发
- 创建连接交由spring容器，避免每次请求的网络开销。
1导包
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
<version>2.0.6.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<version>2.0.6.RELEASE</version>
</dependency>
2配置 application.yml
spring:
application:
name: service-search
dalianpai:
elasticsearch:
hostlist: 192.168.1.106:9200 #多个结点中间用逗号分隔
3代码
主类
配置类
测试类
@SpringBootTest
@RunWith(SpringRunner.class)
//查询文档
@Test
public void testGet() throws IOException {
//构建请求
GetRequest getRequest = new GetRequest("test_post", "1");
//========================可选参数 start======================
//为特定字段配置_source_include
// String[] includes = new String[]{"user", "message"};
// String[] excludes = Strings.EMPTY_ARRAY;
// FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
// getRequest.fetchSourceContext(fetchSourceContext);
//为特定字段配置_source_excludes
// String[] includes1 = new String[]{"user", "message"};
// String[] excludes1 = Strings.EMPTY_ARRAY;
// FetchSourceContext fetchSourceContext1 = new FetchSourceContext(true, includes1, excludes1);
// getRequest.fetchSourceContext(fetchSourceContext1);
//设置路由
// getRequest.routing("routing");
// ========================可选参数 end=====================
//查询 同步查询
GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);
//异步查询
// ActionListener<GetResponse> listener = new ActionListener<GetResponse>() {
// //查询成功时的立马执行的方法
// @Override
// public void onResponse(GetResponse getResponse) {
// long version = getResponse.getVersion();
// String sourceAsString = getResponse.getSourceAsString();//检索文档(String形式)
// System.out.println(sourceAsString);
// }
//
// //查询失败时的立马执行的方法
// @Override
// public void onFailure(Exception e) {
// e.printStackTrace();
// }
// };
// //执行异步请求
// client.getAsync(getRequest, RequestOptions.DEFAULT, listener);
// try {
// Thread.sleep(5000);
// } catch (InterruptedException e) {
// e.printStackTrace();
// }
// 获取结果
if (getResponse.isExists()) {
long version = getResponse.getVersion();
String sourceAsString = getResponse.getSourceAsString();//检索文档(String形式)
System.out.println(sourceAsString);
byte[] sourceAsBytes = getResponse.getSourceAsBytes();//以字节接受
Map<String, Object> sourceAsMap = getResponse.getSourceAsMap();
System.out.println(sourceAsMap);
}else {
}
}
1.4 结合spring-boot-test测试文档新增
rest api
PUT test_post/_doc/2
{
"user":"tomas",
"postDate":"2019-07-18",
"message":"trying out es1"
}
代码：
@Test
public void testAdd() throws IOException {
// 1构建请求
IndexRequest request=new IndexRequest("test_posts");
request.id("3");
// =======================构建文档============================
// 构建方法1
String jsonString="{\n" +
" \"user\":\"tomas J\",\n" +
" \"postDate\":\"2019-07-18\",\n" +
" \"message\":\"trying out es3\"\n" +
"}";
request.source(jsonString, XContentType.JSON);
// 构建方法2
// Map<String,Object> jsonMap=new HashMap<>();
// jsonMap.put("user", "tomas");
// jsonMap.put("postDate", "2019-07-18");
// jsonMap.put("message", "trying out es2");
// request.source(jsonMap);
// 构建方法3
// XContentBuilder builder= XContentFactory.jsonBuilder();
// builder.startObject();
// {
// builder.field("user", "tomas");
// builder.timeField("postDate", new Date());
// builder.field("message", "trying out es2");
// }
// builder.endObject();
// request.source(builder);
// 构建方法4
// request.source("user","tomas",
// "postDate",new Date(),
// "message","trying out es2");
//
// ========================可选参数===================================
//设置超时时间
request.timeout(TimeValue.timeValueSeconds(1));
request.timeout("1s");
//自己维护版本号
// request.version(2);
// request.versionType(VersionType.EXTERNAL);
// 2执行
//同步
IndexResponse indexResponse = client.index(request, RequestOptions.DEFAULT);
//异步
// ActionListener<IndexResponse> listener=new ActionListener<IndexResponse>() {
// @Override
// public void onResponse(IndexResponse indexResponse) {
//
// }
//
// @Override
// public void onFailure(Exception e) {
//
// }
// };
// client.indexAsync(request,RequestOptions.DEFAULT, listener );
// try {
// Thread.sleep(5000);
// } catch (InterruptedException e) {
// e.printStackTrace();
// }
// 3获取结果
String index = indexResponse.getIndex();
String id = indexResponse.getId();
//获取插入的类型
if(indexResponse.getResult()== DocWriteResponse.Result.CREATED){
DocWriteResponse.Result result=indexResponse.getResult();
System.out.println("CREATED:"+result);
}else if(indexResponse.getResult()== DocWriteResponse.Result.UPDATED){
DocWriteResponse.Result result=indexResponse.getResult();
System.out.println("UPDATED:"+result);
}
ReplicationResponse.ShardInfo shardInfo = indexResponse.getShardInfo();
if(shardInfo.getTotal()!=shardInfo.getSuccessful()){
System.out.println("处理成功的分片数少于总分片！");
}
if(shardInfo.getFailed()>0){
for (ReplicationResponse.ShardInfo.Failure failure:shardInfo.getFailures()) {
String reason = failure.reason();//处理潜在的失败原因
System.out.println(reason);
}
}
}
1.5结合spring-boot-test测试文档修改
rest api
post /test_posts/_doc/3/_update
{
"doc": {
"user"："tomas J"
}
}
代码：
@Test
public void testUpdate() throws IOException {
// 1构建请求
UpdateRequest request = new UpdateRequest("test_posts", "3");
Map<String, Object> jsonMap = new HashMap<>();
jsonMap.put("user", "tomas JJ");
request.doc(jsonMap);
//===============================可选参数==========================================
request.timeout("1s");//超时时间
//重试次数
request.retryOnConflict(3);
//设置在继续更新之前，必须激活的分片数
// request.waitForActiveShards(2);
//所有分片都是active状态，才更新
// request.waitForActiveShards(ActiveShardCount.ALL);
// 2执行
// 同步
UpdateResponse updateResponse = client.update(request, RequestOptions.DEFAULT);
// 异步
// 3获取数据
updateResponse.getId();
updateResponse.getIndex();
//判断结果
if (updateResponse.getResult() == DocWriteResponse.Result.CREATED) {
DocWriteResponse.Result result = updateResponse.getResult();
System.out.println("CREATED:" + result);
} else if (updateResponse.getResult() == DocWriteResponse.Result.UPDATED) {
DocWriteResponse.Result result = updateResponse.getResult();
System.out.println("UPDATED:" + result);
}else if(updateResponse.getResult() == DocWriteResponse.Result.DELETED){
DocWriteResponse.Result result = updateResponse.getResult();
System.out.println("DELETED:" + result);
}else if (updateResponse.getResult() == DocWriteResponse.Result.NOOP){
//没有操作
DocWriteResponse.Result result = updateResponse.getResult();
System.out.println("NOOP:" + result);
}
}
1.6结合spring-boot-test测试文档删除
rest api
DELETE /test_posts/_doc/3
代码
@Test
public void testDelete() throws IOException {
// 1构建请求
DeleteRequest request =new DeleteRequest("test_posts","3");
//可选参数
// 2执行
DeleteResponse deleteResponse = client.delete(request, RequestOptions.DEFAULT);
// 3获取数据
deleteResponse.getId();
deleteResponse.getIndex();
DocWriteResponse.Result result = deleteResponse.getResult();
System.out.println(result);
}
1.7结合spring-boot-test测试文档bulk
rest api
POST /_bulk
{"action": {"metadata"}}
{"data"}
代码
@Test
public void testBulk() throws IOException {
// 1创建请求
BulkRequest request = new BulkRequest();
// request.add(new IndexRequest("post").id("1").source(XContentType.JSON, "field", "1"));
// request.add(new IndexRequest("post").id("2").source(XContentType.JSON, "field", "2"));
request.add(new UpdateRequest("post","2").doc(XContentType.JSON, "field", "3"));
request.add(new DeleteRequest("post").id("1"));
// 2执行
BulkResponse bulkResponse = client.bulk(request, RequestOptions.DEFAULT);
for (BulkItemResponse itemResponse : bulkResponse) {
DocWriteResponse itemResponseResponse = itemResponse.getResponse();
switch (itemResponse.getOpType()) {
case INDEX:
case CREATE:
IndexResponse indexResponse = (IndexResponse) itemResponseResponse;
indexResponse.getId();
System.out.println(indexResponse.getResult());
break;
case UPDATE:
UpdateResponse updateResponse = (UpdateResponse) itemResponseResponse;
updateResponse.getIndex();
System.out.println(updateResponse.getResult());
break;
case DELETE:
DeleteResponse deleteResponse = (DeleteResponse) itemResponseResponse;
System.out.println(deleteResponse.getResult());
break;
}
}
}
