Elasticsearch之使用RestClient实现null和非null的查询操作

Posted 2021-08-30 你是小KS

版本：elasticsearch 7.13.4

1. 声明

当前内容主要为使用RestClient实现对Elasticsearch的null字段和非null字段的查询

当前内容基于前面的博文

2. 更新字段并设置值为null

更新属性并设置值为null
之前的内容

	private static void updateDataSetBookNameEqNull(RestClient restClient) throws IOException {
		Request request = new Request("POST", "/book/java/1/_update");
		String json = "{\\"doc\\":{\\"bookName\\":null}}";
		request.setJsonEntity(json);
		Response response = restClient.performRequest(request);
		System.out.println(response);
	}

执行后

3. 开始执行对非null的查询(exisits)

	/**
	 * 
	 * @author hy
	 * @createTime 2021-07-31 16:06:44
	 * @description 查询当前bookName不是null的数据
	 * @param restClient
	 * @throws IOException
	 *
	 */
	private static void selectDataWhereBookNameIsNotNull(RestClient restClient) throws IOException {
		String encode = URLEncoder.encode("_exists_:bookName", "UTF-8");
		Request request = new Request("GET", "/book/java/_search?q="+encode);
		
		Response response = restClient.performRequest(request);
		System.out.println(response);
		String result = getResponseContent(response);
		System.out.println(result);
	}

查询结果

八月 01, 2021 11:59:47 上午 org.elasticsearch.client.RestClient logResponse
警告: request [GET http://localhost:9200/_nodes/http?timeout=1000ms] returned 1 warnings: [299 Elasticsearch-7.13.4-c5f60e894ca0c61cdbae4f5a686d9f08bcefc942 "Elasticsearch built-in security features are not enabled. Without authentication, your cluster could be accessible to anyone. See https://www.elastic.co/guide/en/elasticsearch/reference/7.13/security-minimal-setup.html to enable security."]
八月 01, 2021 11:59:47 上午 org.elasticsearch.client.RestClient logResponse
警告: request [GET http://localhost:9200/book/java/_search?q=_exists_%3AbookName] returned 2 warnings: [299 Elasticsearch-7.13.4-c5f60e894ca0c61cdbae4f5a686d9f08bcefc942 "Elasticsearch built-in security features are not enabled. Without authentication, your cluster could be accessible to anyone. See https://www.elastic.co/guide/en/elasticsearch/reference/7.13/security-minimal-setup.html to enable security."],[299 Elasticsearch-7.13.4-c5f60e894ca0c61cdbae4f5a686d9f08bcefc942 "[types removal] Specifying types in search requests is deprecated."]
Response{requestLine=GET /book/java/_search?q=_exists_%3AbookName HTTP/1.1, host=http://localhost:9200, response=HTTP/1.1 200 OK}
{"took":2,"timed_out":false,"_shards":{"total":1,"successful":1,"skipped":0,"failed":0},"hits":{"total":{"value":0,"relation":"eq"},"max_score":null,"hits":[]}}

没有任何数据匹配！

主要使用q=_exisits_:字段方式查询非null的字段

4. 开始执行对null的查询

/**
	 * 
	 * @author hy
	 * @createTime 2021-07-31 16:06:44
	 * @description 查询当前bookName=null的数据
	 * @param restClient
	 * @throws IOException
	 *
	 */
	private static void selectDataWhereBookNameIsNull(RestClient restClient) throws IOException {
		// 错误，无法查询
		// String encode = URLEncoder.encode("bookName:null", "UTF-8");
		Request request = new Request("GET", "/book/java/_search");
		request.setJsonEntity( "{\\"query\\": {\\"bool\\": {\\"must_not\\": {\\"exists\\": {\\"field\\": \\"bookName\\"}}}}}");
		Response response = restClient.performRequest(request);
		
		System.out.println(response);
		String result = getResponseContent(response);
		System.out.println(result);
	}
	

结果

八月 01, 2021 11:57:47 上午 org.elasticsearch.client.RestClient logResponse
警告: request [GET http://localhost:9200/_nodes/http?timeout=1000ms] returned 1 warnings: [299 Elasticsearch-7.13.4-c5f60e894ca0c61cdbae4f5a686d9f08bcefc942 "Elasticsearch built-in security features are not enabled. Without authentication, your cluster could be accessible to anyone. See https://www.elastic.co/guide/en/elasticsearch/reference/7.13/security-minimal-setup.html to enable security."]
八月 01, 2021 11:57:48 上午 org.elasticsearch.client.RestClient logResponse
警告: request [GET http://localhost:9200/book/java/_search] returned 2 warnings: [299 Elasticsearch-7.13.4-c5f60e894ca0c61cdbae4f5a686d9f08bcefc942 "Elasticsearch built-in security features are not enabled. Without authentication, your cluster could be accessible to anyone. See https://www.elastic.co/guide/en/elasticsearch/reference/7.13/security-minimal-setup.html to enable security."],[299 Elasticsearch-7.13.4-c5f60e894ca0c61cdbae4f5a686d9f08bcefc942 "[types removal] Specifying types in search requests is deprecated."]
Response{requestLine=GET /book/java/_search HTTP/1.1, host=http://localhost:9200, response=HTTP/1.1 200 OK}
{"took":359,"timed_out":false,"_shards":{"total":1,"successful":1,"skipped":0,"failed":0},"hits":{"total":{"value":1,"relation":"eq"},"max_score":0.0,"hits":[{"_index":"book","_type":"java","_id":"1","_score":0.0,"_source":{"bookName":null,"id":2,"price":66.6}}]}}

可以查询到