Elastic Search Java REST Advanced Client Inline Template

ElasticSearch 7.2.0

1. Inline template

2. Create registration template

3. Execute registration template

4. Create Client

5.maven configuration - pom file

 

1. Inline template

/**
	 * Inline template
	 */
	public static void inlineTemplate() {
		//Get Client
		var client = getClient();
		SearchTemplateRequest request = new SearchTemplateRequest();
		//Specified index
		request.setRequest(new SearchRequest("movies"));
		//Set to Inline
		request.setScriptType(ScriptType.INLINE);
		//Setup script
		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);
			//Output query results
			response.getResponse().getHits().forEach(System.out::println);
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			//Close the client
			close(client);
		}
	}

2. Create registration templates

If the client of the registration template uses the low-level client, the high-level client does not provide the registration template.
Registered Template recommends executing commands directly instead of in java. Registered Template in Java needs to be redistributed when changes are made.

/**
	 * Registration template < br >
	 * If the client of registration template uses low-level client, the high-level client does not provide registration template < br>.
	 * Registered Template recommends executing commands directly instead of in java. Registered Template in Java needs to be republished < br> when changing.
	 * @return Returns whether the registration template was successfully registered
	 */
	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);
			// Response status lines from which status codes can be obtained
			statusCode = response.getStatusLine().getStatusCode();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			close(client);
		}
		return statusCode;
	}

3. Execute registration template

 

/**
	 * Execute registration template
	 */
	public static void runRegisterTemplate() {
		int statusCode = registerTemplate();
		
		// Search templates can be pre-registered through stored script API s.
		// Note that the stored script API is not yet available in the advanced REST client, so in this case, we use the low-level REST client.
		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);

			// Given the parameter values, the template can be rendered without performing the search:
			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 Automatically Generated catch Block
				e.printStackTrace();
			}finally {
				try {
					rHClient.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}

4. Create Client

Creating Advanced Client

Creating low-level clients

Close the client

/**
	 * 
	 * Close the client
	 * 
	 * @param client
	 */
	private static void close(Closeable client) {
		try {
			client.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/**
	 * Get Client
	 * 
	 * @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;
	}

	/**
	 * Getting low-level clients
	 * 
	 * @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;
	}

5.maven configuration - pom

Elastic search Java REST advanced client maven configuration

https://blog.csdn.net/u014646662/article/details/97895028