<dependency>

        <groupId>org.elasticsearch.client</groupId>

        <artifactId>elasticsearch-rest-high-level-client</artifactId>

        <version>7.2.0</version>

</dependency>

RestHighLevelClient client = new RestHighLevelClient(

                RestClient.builder(new HttpHost("10.8.3.55", 9200, "http")));

// 1. 检测索引是否存在(所有和索引有关的操作全部推荐用org.elasticsearch.client.indices包下的类)

        GetIndexRequest request = new GetIndexRequest("twitter");

        boolean exists = client.indices().exists(request, RequestOptions.DEFAULT);

        System.out.println(exists);

// 2. 创建索引

        CreateIndexRequest request = new CreateIndexRequest("twitter");

        request.settings(Settings.builder()

                .put("index.number_of_shards", 1)

                .put("index.number_of_replicas", 1)

        );

        // 第一种

        request.mapping("{\"properties\":{\"msg\":{\"type\":\"text\"}}}", XContentType.JSON);

        // 第二种

        Map<String, Object> properties = new HashMap<>();// properties

        Map<String, Object> message = new HashMap<>();

        message.put("type", "text");

        properties.put("message", message);// 添加映射

        Map<String, Object> username = new HashMap<>();

        username.put("type", "keyword");

        properties.put("username", username);// 添加映射

        Map<String, Object> mapping = new HashMap<>();

        mapping.put("properties", properties);

        request.mapping(mapping);

        CreateIndexResponse createIndexResponse = client.indices().create(request, RequestOptions.DEFAULT);

        System.out.println(createIndexResponse.index());

// 3. 增加文档(如果类注释推荐使用org.elasticsearch.client.Requests来创建类,最好用他推荐的方式)

        IndexRequest request = Requests.indexRequest("twitter");

        request.id("1");// 指定ID

        request.source("message", "消息内容...abc",

                "username", "jack 杰克");// 支持多种方式

        IndexResponse indexResponse = client.index(request, RequestOptions.DEFAULT);

        System.out.println(indexResponse);

// 4. 修改文档

        UpdateRequest request = new UpdateRequest("twitter", "1");

        request.doc("message", "修改之后的消息内容...abc",

                "username", "修改之后的jack 杰克");// 支持多种方式

        UpdateResponse response = client.update(request, RequestOptions.DEFAULT);

        System.out.println(response);

// 5. Bulk

        BulkRequest request = new BulkRequest();

        request.add(new DeleteRequest("twitter", "1"));

        request.add(new UpdateRequest("twitter", "2")

                .doc(XContentType.JSON,"username", "jack==="));

        request.add(new IndexRequest("twitter").id("3")

                .source(XContentType.JSON,"username", "jack222"));

        BulkResponse response = client.bulk(request, RequestOptions.DEFAULT);

        System.out.println(response.hasFailures());

// 6. 根据ID获取文档

        GetRequest request = Requests.getRequest("twitter").id("2");

        GetResponse response = client.get(request, RequestOptions.DEFAULT);

        System.out.println(response.getSourceAsString());

        // 7. Search

        SearchRequest request = new SearchRequest("twitter");

        SearchSourceBuilder builder = new SearchSourceBuilder();

        builder.query(QueryBuilders.matchAllQuery());
        request.source(builder);

        SearchResponse response = client.search(request, RequestOptions.DEFAULT);

        Iterator<SearchHit> hits = response.getHits().iterator();

        ObjectMapper mapper = new ObjectMapper();

        List<Person> personList = new ArrayList<>();

        while (hits.hasNext()) {

            personList.add(mapper.readValue(hits.next().getSourceAsString(), Person.class));

        }

        System.out.println(personList);

//   样例 伪代码:

//        SearchSourceBuilder builder = new SearchSourceBuilder();

//        String[] include = {"timeStamp",

//                "msgBody.boxList.boxStatus.boxCurrent",

//                "msgBody.boxList.batInfo.batSN",

//                "msgBody.boxList.batStatus.batCurrent",

//                "msgBody.boxList.batStatus.batVoltage",

//                "msgBody.boxList.batStatus.batRSOC"};

//        builder.query(QueryBuilders.boolQuery()

////                .filter(QueryBuilders.termQuery("msgBody.boxList.batInfo.batSN", "BAA2118122200104"))

//                .filter(QueryBuilders.rangeQuery("timeStamp").gte(1557729000).lte(1557741600)))

//                .sort("timeStamp", SortOrder.ASC)

//                .from(0)

//                .size(100).fetchSource(include, null);

////        builder.aggregation(AggregationBuilders.terms("data_count").field("deviceInfo.deviceSN")).size(0);

Terms data = response.getAggregations().get("data_count");

        System.out.println(data.getBuckets().get(0).getKey());

        System.out.println(data.getBuckets().get(0).getDocCount());

        System.out.println(response.toString());