Elasticsearch介绍（三 ）使用RestHighLevelClient操作java api

之前我们介绍了elasticsearch的安装，这里我们实战一下，看下具体的java api如何操作。话不多说，直接开始

一、添加maven依赖

                <dependency>
			<groupId>org.elasticsearch</groupId>
			<artifactId>elasticsearch</artifactId>
			<version>7.7.0</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.elasticsearch.client/elasticsearch-rest-high-level-client -->
		<dependency>
			<groupId>org.elasticsearch.client</groupId>
			<artifactId>elasticsearch-rest-high-level-client</artifactId>
			<version>7.7.0</version>
		</dependency>

二、代码的公共部分

         RestHighLevelClient client = null;

	@Before
	public void init() {
		client = new RestHighLevelClient(RestClient.builder(new HttpHost("192.168.31.20", 9200, "http")));
	}

	@After
	public void destroy() {
		try {
			if (null != client) {
				client.close();
			}
		} catch (Exception e) {
			log.error(e.getMessage(), e);
		}
	}

三、创建与查看index

1）创建index

/**
	 * 创建一个索引
	 * 
	 * @throws Exception
	 */
	@Test
	public void createIndex() throws Exception {
		CreateIndexRequest request = new CreateIndexRequest("test");
		// 设置创建的索引的分片和副本数
		request.settings(Settings.builder().put("index.number_of_shards", 2).put("index.number_of_replicas", 1));
		// 设置初始化的mapping
		String mapping = this.getMapping();
		request.mapping("doc", mapping,XContentType.JSON);
		CreateIndexResponse response = client.indices().create(request, RequestOptions.DEFAULT);
		log.info("创建index索引的结果是：{}", JSON.toJSONString(response));
	}

/**
	 * 设置mapping
	 * 
	 * @return
	 */
	private String getMapping() {
		
		HashMap<String, Object> doc = new HashMap<String, Object>();
		
		HashMap<String, Object> properties = new HashMap<String, Object>();

		HashMap<String, Object> name = new HashMap<String, Object>();
		name.put("type", "text");

		HashMap<String, Object> model = new HashMap<String, Object>();
		model.put("type", "keyword");

		properties.put("name", name);
		properties.put("model", model);

		doc.put("properties", properties);
		
		log.info("准备创建的mapping是：{}", JSON.toJSONString(doc));

		return JSON.toJSONString(doc);
	}

2）查看index

/**
	 * 查看索引信息
	 * 
	 * @throws IOException
	 */
	@Test
	public void showIndex() throws IOException {
		GetIndexRequest request = new GetIndexRequest();
		request.indices("test");
		GetIndexResponse response = client.indices().get(request, RequestOptions.DEFAULT);
		log.info("查看对应索引的信息 aliases:{}", response.getAliases());
		log.info("查看对应索引的信息 mapping:{}", JSON.toJSONString());
		log.info("查看对应索引的信息 setting:{}", response.getSettings());
	}

四、插入数据

1）单条插入数据

        @Test
	public void insertData() throws Exception {
		IndexRequest request = new IndexRequest("user");
		Map<String, Object> jsonMap = new HashMap<>();
		jsonMap.put("username", "张三");
		jsonMap.put("password", "123456");
		request.source(jsonMap);
		IndexResponse response = client.index(request, RequestOptions.DEFAULT);
		log.info("添加单条索引的结果是：{}",JSON.toJSONString(response));
	}

2）批量插入数据

        @Test
	public void bulkInsertData() throws Exception {
		List<Map<String, Object>> list = new ArrayList<>();
		for (int i = 0; i < 100; i++) {
			Map<String, Object> jsonMap = new HashMap<>();
			jsonMap.put("username", "张三");
			jsonMap.put("password", "123456" + i);
			list.add(jsonMap);
		}
		/**
		 * 批量从插入数据
		 */
		BulkRequest request = new BulkRequest();
		for (int j = 0; j < list.size(); j++) {
			Map<String, Object> item = list.get(j);
			request.add(new IndexRequest("user").source(item));
		}
		BulkResponse response = client.bulk(request, RequestOptions.DEFAULT);
		log.info("批量添加索引的结果是：{}", JSON.toJSONString(response));
	}

五、查询

1）查询全部

        @Test
	public void queryAll() throws Exception {
		SearchRequest request = new SearchRequest();
		SearchResponse response = client.search(request, RequestOptions.DEFAULT);
		log.info("查询全部获取的结果是：{}", JSON.toJSONString(response));
	}

2）根据id进行查询

        @Test
	public void getById() throws Exception {

		GetRequest request = new GetRequest("user", "z2aNzYEBa29IIbHz8EaE");
		GetResponse response = client.get(request, RequestOptions.DEFAULT);
		log.info("getById获取的结果是：{}", JSON.toJSONString(response));
	}

3）根据关键词查询

        @Test
	public void queryByKeyWord() throws Exception {
		SearchRequest request = new SearchRequest("user");
		SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
		TermQueryBuilder termQuery = QueryBuilders.termQuery("password", "12345628");
		searchSourceBuilder.query(termQuery);
		request.source(searchSourceBuilder);
		SearchResponse response = client.search(request, RequestOptions.DEFAULT);
		log.info("查询全部获取的结果是：{}", JSON.toJSONString(response));
	}

根据关键词进行搜索的情况，主要是编写querybuilder即可，所以其他的querybuilder就暂时不在这列举了。

六、更新

    @Test
	public void updateDocumentById() throws Exception {
		Map<String, Object> jsonMap = new HashMap<>();
		jsonMap.put("username", "李四");
		jsonMap.put("password", "111");
		
		UpdateRequest request = new UpdateRequest("user","z2aNzYEBa29IIbHz8EaE").doc(jsonMap);
		UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
		log.info("updateDocumentById获取的结果是：{}", JSON.toJSONString(response));
	}

七、删除

1）根据id删除

        @Test
	public void deleteById() throws Exception {
		DeleteRequest request = new DeleteRequest("user","z2aNzYEBa29IIbHz8EaE");
		DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);
		log.info("deleteById获取的结果是：{}", JSON.toJSONString(response));
	}

2）根据条件删除

        @Test
	public void deleteByQuery() throws Exception {

		DeleteByQueryRequest request = new DeleteByQueryRequest("user");
		request.setQuery(new TermQueryBuilder("password", "12345613"));
		// 更新最大文档数
        request.setSize(10);
        // 批次大小
        request.setBatchSize(1000);
        // 并行
        request.setSlices(2);
        // 使用滚动参数来控制“搜索上下文”存活的时间
        request.setScroll(TimeValue.timeValueMinutes(10));
        // 超时
        request.setTimeout(TimeValue.timeValueMinutes(2));
        // 刷新索引
        request.setRefresh(true);
        BulkByScrollResponse  response = client.deleteByQuery(request, RequestOptions.DEFAULT);
		log.info("deleteById获取的结果是：{}", JSON.toJSONString(response));
	}