ElasticSearch Java REST 高级客户端查询模板 SearchTemplate

雨点打透心脏的1/2处 2021-11-04 13:58 308阅读 0赞

# ElasticSearch Java REST 高级客户端 内联模板 SearchTemplate #

ElasticSearch 7.2.0

1.内联模板

2.创建注册模板

3.执行注册模板

4.多模板

5.创建客户端

6.maven配置---pom文件

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[https://www.cbedai.net/u014646662][Link 1]

# 1.内联模板 #

/**
    	 * 内联模板
    	 */
    	public static void inlineTemplate() {
    		//获取客户端
    		var client = getClient();
    		SearchTemplateRequest request = new SearchTemplateRequest();
    		//指定索引
    		request.setRequest(new SearchRequest("movies"));
    		//设置为内联
    		request.setScriptType(ScriptType.INLINE);
    		//设置脚本
    		request.setScript("{" + "  \"query\": { \"match\" : { \"{
       {field}}\" : \"{
       {value}}\" } },"
    				+ "  \"size\" : \"{
       {size}}\"" + "}");
    
    		Map<String, Object> scriptParams = new HashMap<>();
    		scriptParams.put("field", "title");
    		scriptParams.put("value", "life");
    		scriptParams.put("size", 5);
    		request.setScriptParams(scriptParams);
    
    		try {
    			SearchTemplateResponse response = client.searchTemplate(request, RequestOptions.DEFAULT);
    			//输出查询结果
    			response.getResponse().getHits().forEach(System.out::println);
    		} catch (IOException e) {
    			e.printStackTrace();
    		} finally {
    			//关闭客户端
    			close(client);
    		}
    	}

## 2.创建注册模板 ##

注册模板的客户端要是用低级客户端，高级客户端没有提供注册模板  
注册模板建议直接执行命令，不要再java中执行，在java中做注册模板，变更时需要重新发布

/**
    	 * 注册模板 <br>
    	 * 注册模板的客户端要是用低级客户端，高级客户端没有提供注册模板<br>
    	 * 注册模板建议直接执行命令，不要再java中执行，在java中做注册模板，变更时需要重新发布<br>
    	 * @return 返回注册模板是否注册成功
    	 */
    	private static int registerTemplate() {
    		var client = getLowClient();
    		Request scriptRequest = new Request("POST", "_scripts/movies_script");
    		String json = "{" +
    			    "  \"script\": {" +
    			    "    \"lang\": \"mustache\"," +
    			    "    \"source\": {" +
    			    "      \"query\": { \"match\" : { \"{
       {field}}\" : \"{
       {value}}\" } }," +
    			    "      \"size\" : \"{
       {size}}\"" +
    			    "    }" +
    			    "  }" +
    			    "}";
    		scriptRequest.setJsonEntity(json);
    
    		int statusCode = -1;
    		try {
    			Response response = client.performRequest(scriptRequest);
    			// 响应状态行，可以从中获取状态码
    			statusCode = response.getStatusLine().getStatusCode();
    		} catch (IOException e) {
    			e.printStackTrace();
    		} finally {
    			close(client);
    		}
    		return statusCode;
    	}

## 3.执行注册模板 ##

/**
    	 * 执行注册模板
    	 */
    	public static void runRegisterTemplate() {
    		int statusCode = registerTemplate();
    		
    		// 可以通过存储的脚本API预先注册搜索模板。
    		// 注意，存储的脚本API在高级REST客户机中还不可用，因此在本例中，我们使用低级REST客户机。
    		if (statusCode == 200) {
    			SearchTemplateRequest request = new SearchTemplateRequest();
    			request.setRequest(new SearchRequest("movies"));
    
    			request.setScriptType(ScriptType.STORED);
    			request.setScript("movies_script");
    
    			Map<String, Object> params = new HashMap<>();
    			params.put("field", "title");
    			params.put("value", "life");
    			params.put("size", 5);
    			request.setScriptParams(params);
    
    			// 给定参数值，模板可以在不执行搜索的情况下呈现:
    			request.setSimulate(true);
    			
    			request.setExplain(true);
    			request.setProfile(true);
    			RestHighLevelClient rHClient = getClient();
    			try {
    				SearchTemplateResponse response = rHClient.searchTemplate(request, RequestOptions.DEFAULT);
    				
    				SearchTemplateRequest request2 = new SearchTemplateRequest();
    				request2.setRequest(new SearchRequest("movies"));
    				request2.setScriptType(ScriptType.INLINE);
    				request2.setScript(response.getSource().utf8ToString());
    				request2.setScriptParams(new HashMap<String, Object>());
    				response = rHClient.searchTemplate(request2, RequestOptions.DEFAULT);
    				SearchResponse sResponse = response.getResponse();
    				SearchHits hits = sResponse.getHits();
    				if(hits != null) {
    					for (SearchHit hit : hits) {
    						System.out.println(hit.getSourceAsString());
    					}
    				}
    			} catch (IOException e) {
    				// TODO 自动生成的 catch 块
    				e.printStackTrace();
    			}finally {
    				try {
    					rHClient.close();
    				} catch (IOException e) {
    					e.printStackTrace();
    				}
    			}
    		}
    	}

## 4.多模板 ##

public static void mulitTemplate() {
    		RestHighLevelClient client = getClient();
    		String [] searchTerms = {"life", "mom", "girl"};
    
    		MultiSearchTemplateRequest multiRequest = new MultiSearchTemplateRequest(); 
    		for (String searchTerm : searchTerms) {
    		    SearchTemplateRequest request = new SearchTemplateRequest();  
    		    request.setRequest(new SearchRequest("movies"));
    
    		    request.setScriptType(ScriptType.INLINE);
    		    request.setScript(
    		        "{" +
    		        "  \"query\": { \"match\" : { \"{
       {field}}\" : \"{
       {value}}\" } }," +
    		        "  \"size\" : \"{
       {size}}\"" +
    		        "}");
    
    		    Map<String, Object> scriptParams = new HashMap<>();
    		    scriptParams.put("field", "title");
    		    scriptParams.put("value", searchTerm);
    		    scriptParams.put("size", 1);
    		    request.setScriptParams(scriptParams);
    		    multiRequest.add(request);
    		}
    		
    		try {
    			MultiSearchTemplateResponse multiResponse = client.msearchTemplate(multiRequest, RequestOptions.DEFAULT);
    			multiResponse.forEach(item -> item.getResponse().getResponse().getHits().forEach(System.out::println));
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    	}

## 5.创建客户端 ##

创建高级客户端

创建低级客户端

关闭客户端

/**
    	 * 
    	 * 关闭客户端
    	 * 
    	 * @param client
    	 */
    	private static void close(Closeable client) {
    		try {
    			client.close();
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    	}
    
    	/**
    	 * 获取客户端
    	 * 
    	 * @return
    	 */
    	private static RestHighLevelClient getClient() {
    		RestHighLevelClient client = new RestHighLevelClient(
    				RestClient.builder(new HttpHost("elk-node01", 9200, "http"), new HttpHost("elk-node02", 9200, "http"),
    						new HttpHost("elk-node03", 9200, "http")));
    		return client;
    	}
    
    	/**
    	 * 获取低级客户端
    	 * 
    	 * @return
    	 */
    	private static RestClient getLowClient() {
    		RestClient client = RestClient.builder(new HttpHost("elk-node01", 9200, "http"),
    				new HttpHost("elk-node02", 9200, "http"), new HttpHost("elk-node03", 9200, "http")).build();
    		return client;
    	}

## 6.maven配置---pom ##

Elasticsearch Java REST高级客户端 maven配置

[https://blog.csdn.net/u014646662/article/details/97895028][https_blog.csdn.net_u014646662_article_details_97895028]

[Link 1]: https://www.cbedai.net/u014646662
[https_blog.csdn.net_u014646662_article_details_97895028]: https://blog.csdn.net/u014646662/article/details/97895028