1. 依赖

<dependencies>
    <!-- elasticsearch -->
    <dependency>
        <groupId>org.elasticsearch</groupId>
        <artifactId>elasticsearch</artifactId>
        <version>7.8.0</version>
    </dependency>
    <!-- elasticsearch 的客户端 -->
    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>elasticsearch-rest-high-level-client</artifactId>
        <version>7.8.0</version>
    </dependency>
    <!-- elasticsearch 依赖 2.x 的 log4j -->
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-api</artifactId>
        <version>2.8.2</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-core</artifactId>
        <version>2.8.2</version>
    </dependency>
    <!-- jackson -->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.9</version>
    </dependency>
</dependencies>

2. 客户端

早期版本的客户端对象已经不再推荐使用，且在未来版本中会被删除，所以这里采用高级 REST 客户端对象

/**
 * ES 客户端的创建
 * @author JShawn 2021/8/5 11:24
 */
public class EsClient_Test {
    /**
     * ES集群地址
     */
    private static final String ES_CLUSTER_HOST_PORT = "hadoop101:9200,hadoop102:9200,hadoop103:9200";
    /**
     * ES连接方式
     */
    private static final String ES_SCHEMA = "http";
    public static void main(String[] args) throws IOException {
        // 1. 获取ES客户端
        // 1. ES地址配置
        String[] clusters = ES_CLUSTER_HOST_PORT.split(",");
        HttpHost[] hosts = new HttpHost[clusters.length];
        for (int i = 0; i < clusters.length; i++) {
            String[] address = clusters[i].split(":");
            HttpHost httpHost = new HttpHost(address[0], Integer.parseInt(address[1]), ES_SCHEMA);
            hosts[i] = httpHost;
        }
        // 2. 创建客户端
        RestHighLevelClient restHighLevelClient = new RestHighLevelClient(RestClient.builder(hosts));
        // 3. 关闭客户端
        restHighLevelClient.close();
    }
}

3. 索引

3.1 创建—-CreateIndexRequest

/**
 * 1. 创建索引
 * @param restHighLevelClient   ES客户端
 * @throws IOException
 */
private static void createIndex(RestHighLevelClient restHighLevelClient) throws IOException {
    CreateIndexRequest indexRequest = new CreateIndexRequest("car");
    CreateIndexResponse response = restHighLevelClient.indices().create(indexRequest, RequestOptions.DEFAULT);
    LOGGER.info(response.isAcknowledged());
}

3.2 查询

3.2.1 查询单个索引—-GetIndexRequest

/**
 * 2. 查看单个索引
 *
 * @param restHighLevelClient   ES客户端
 */
private static void getIndex(RestHighLevelClient restHighLevelClient) throws IOException {
    GetIndexRequest getIndexRequest = new GetIndexRequest("car");
    GetIndexResponse response = restHighLevelClient.indices().get(getIndexRequest, RequestOptions.DEFAULT);
    LOGGER.info("别名：" + response.getAliases());
    LOGGER.info("indices：" + response.getIndices());
    LOGGER.info("映射结构：" + response.getMappings());
    LOGGER.info("settings：" + response.getSettings());
}

3.2.2 查询全部索引—-GetAliasesRequest

/**
 * 3. 查看全部索引
 *
 * @param restHighLevelClient   ES客户端
 */
private static void getAllIndex(RestHighLevelClient restHighLevelClient) throws IOException {
    GetAliasesRequest aliasesRequest = new GetAliasesRequest();
    GetAliasesResponse response = restHighLevelClient.indices().getAlias(aliasesRequest,RequestOptions.DEFAULT);
    Map<String, Set<AliasMetadata>> aliases = response.getAliases();
    Set<String> indices = aliases.keySet();
    for (String key : indices) {
        LOGGER.info("索引：" + key);
    }
}

3.3 删除—-DeleteIndexRequest

/**
 * 4. 删除索引
 *
 * @param restHighLevelClient   ES客户端
 */
private static void deleteIndex(RestHighLevelClient restHighLevelClient) throws IOException {
    DeleteIndexRequest deleteRequest = new DeleteIndexRequest("student1");
    AcknowledgedResponse response = restHighLevelClient.indices().delete(deleteRequest, RequestOptions.DEFAULT);
    LOGGER.info(response.isAcknowledged());
}

4. 文档

4.1 新增

4.1.1 单文档新增—-IndexRequest

/**
 * 1.新增文档
 *
 * @param restHighLevelClient   ES客户端
 */
private static void insertDoc(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建数据，再转换成json
    Car car = new Car("BMW", "blue", 300000);
    ObjectMapper objectMapper = new ObjectMapper();
    String carJson = objectMapper.writeValueAsString(car);
    // 2. 封装数据
    IndexRequest request = new IndexRequest("car");
    // 2.1 设置唯一性标识，不设置ES自动生成
    request.id("1001");
    // 2.2 将数据封装到请求体中
    request.source(carJson,XContentType.JSON);
    // 3. 发送请求，获取响应
    IndexResponse response = restHighLevelClient.index(request, RequestOptions.DEFAULT);
    LOGGER.info("index：" + response.getIndex());
    LOGGER.info("id：" + response.getId());
    LOGGER.info("result：" + response.getResult());
}

4.1.2 批量新增—-BulkRequest

/**
 * 2. 批量新增文档
 *
 * @param restHighLevelClient   ES客户端
 */
private static void batchInsertDoc(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建BulkRequest对象
    BulkRequest bulkRequest = new BulkRequest();
    // 2. 封装数据
    bulkRequest.add(new IndexRequest("car").id("1001").source(XContentType.JSON, "name", "bmw", "color", "blue", "price", 300000));
    bulkRequest.add(new IndexRequest("car").id("1002").source(XContentType.JSON, "name", "audi", "color", "write", "price", 400000));
    bulkRequest.add(new IndexRequest("car").id("1003").source(XContentType.JSON, "name", "bens", "color", "black", "price", 500000));
    bulkRequest.add(new IndexRequest("car").id("1004").source(XContentType.JSON, "name", "bmw", "color", "yellow", "price", 600000));
    bulkRequest.add(new IndexRequest("car").id("1005").source(XContentType.JSON, "name", "audi", "color", "blue", "price", 700000));
    bulkRequest.add(new IndexRequest("car").id("1006").source(XContentType.JSON, "name", "bens", "color", "blue", "price", 800000));
    // 3. 发送请求，获取响应
    BulkResponse response = restHighLevelClient.bulk(bulkRequest, RequestOptions.DEFAULT);
    LOGGER.info("用时：" + response.getTook());
    LOGGER.info("items：" + response.getItems());
}

4.2 修改—-UpdateRequest

/**
 * 3. 修改文档
 *
 * @param restHighLevelClient ES客户端
 */
private static void updateDoc(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建UpdateRequest对象
    UpdateRequest request = new UpdateRequest();
    // 2.封装数据
    request.index("car");
    request.id("1004");
    request.doc(XContentType.JSON, "color", "yellow");
    // 3. 发送请求，获取响应
    UpdateResponse response = restHighLevelClient.update(request, RequestOptions.DEFAULT);
    LOGGER.info("_index:" + response.getIndex());
    LOGGER.info("_id:" + response.getId());
    LOGGER.info("_result:" + response.getResult());
}

4.3 删除

4.3.1 主键删除—-DeleteRequest

/**
 * 5. 主键删除文档
 *
 * @param restHighLevelClient   ES客户端
 */
private static void deleteDoc(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建DeleteRequest对象
    DeleteRequest deleteRequest = new DeleteRequest("car");
    // 2.封装数据
    deleteRequest.id("1004");
    // 3. 发送请求，获取响应
    DeleteResponse response = restHighLevelClient.delete(deleteRequest, RequestOptions.DEFAULT);
    LOGGER.info(response.toString());
}

4.3.2 批量删除—-BulkRequest

/**
 * 6. 批量删除文档
 * @param restHighLevelClient   ES客户端
 */
private static void batchDeleteDoc(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建BulkRequest对象
    BulkRequest request = new BulkRequest();
    // 2. 封装数据
    request.add(new DeleteRequest("car").id("1001"));
    request.add(new DeleteRequest("car").id("1002"));
    request.add(new DeleteRequest("car").id("1003"));
    request.add(new DeleteRequest("car").id("1004"));
    request.add(new DeleteRequest("car").id("1005"));
    request.add(new DeleteRequest("car").id("1006"));
    // 3. 发送请求，获取响应
    BulkResponse response = restHighLevelClient.bulk(request, RequestOptions.DEFAULT);
    LOGGER.info("took:" + response.getTook());
    LOGGER.info("items:" + response.getItems());
}

4.4 查询

4.3.1 主键查询—-GetRequest

/**
 * 4. 查询文档
 *
 * @param restHighLevelClient   ES客户端
 */
private static void getDoc(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建GetRequest对象
    GetRequest request = new GetRequest("car");
    // 2.封装数据
    request.id("1001");
    // 3. 发送请求，获取响应
    GetResponse response = restHighLevelClient.get(request, RequestOptions.DEFAULT);
    LOGGER.info("_index:" + response.getIndex());
    LOGGER.info("_type:" + response.getType());
    LOGGER.info("source" + response.getSourceAsString());
}

4.3.2 高级查询—-SearchRequest

4.3.2.1 全量查询—-matchAllQuery()

/**
 * 2. 全量查询 --- matchAllQuery()
 *
 * @param restHighLevelClient   ES客户端
 */
private static void getAllDoc(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建搜索请求对象
    SearchRequest request = new SearchRequest();
    request.indices("car");
    // 2. 构建查询请求体
    SearchSourceBuilder builder = new SearchSourceBuilder();
    builder.query(QueryBuilders.matchAllQuery());
    request.source(builder);
    // 3. 发送请求，接收响应
    SearchResponse response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
    SearchHits hits = response.getHits();
    LOGGER.info("耗时：" + response.getTook());
    LOGGER.info("是否超时：" + response.isTimedOut());
    LOGGER.info("总数：" + hits.getTotalHits());
    LOGGER.info("maxScore：" + hits.getMaxScore());
    LOGGER.info("hits =======================>>");
    for (SearchHit hit : hits) {
        // 4. 输出数据
        LOGGER.info(hit.getSourceAsString());
    }
    LOGGER.info("<<========================");
}

4.3.2.2 条件查询—-termQuery(“字段”, “值”)

注意：term条件不分词，keyword不分词，text分词

/**
 * 3. 条件查询---termQuery("字段", "值")
 *
 * @param restHighLevelClient   ES客户端
 */
private static void getDocByTermQuery(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建搜索请求对象
    SearchRequest request = new SearchRequest("car");
    // 2. ******构建查询请求体******
    SearchSourceBuilder builder = new SearchSourceBuilder();
    builder.query(QueryBuilders.termQuery("name", "bmw"));
    request.source(builder);
    // 3. 发送请求，接收响应
    SearchResponse response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
    SearchHits hits = response.getHits();
    LOGGER.info("耗时：" + response.getTook());
    LOGGER.info("是否超时：" + response.isTimedOut());
    LOGGER.info("总数：" + hits.getTotalHits());
    LOGGER.info("maxScore：" + hits.getMaxScore());
    LOGGER.info("hits =======================>>");
    for (SearchHit hit : hits) {
        // 4. 输出数据
        LOGGER.info(hit.getSourceAsString());
    }
    LOGGER.info("<<========================");
}

4.3.2.3 通配符查询—-wildcardQuery(“字段”, “值“)

注意：wildcard条件不分词，keyword不分词，text分词

/**
 * 4. 通配符查询 --- wildcardQuery("字段", "*值*")
 *
 * @param restHighLevelClient   ES客户端
 * @throws IOException
 */
private static void getDocByWildcard(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建搜索请求对象
    SearchRequest request = new SearchRequest("car");
    // 2.******构建查询请求体******
    SearchSourceBuilder builder = new SearchSourceBuilder();
    WildcardQueryBuilder wildcardQueryBuilder = QueryBuilders.wildcardQuery("name", "*m*");
    builder.query(wildcardQueryBuilder);
    request.source(builder);
    // 3. 发送请求，接收响应
    SearchResponse response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
    SearchHits hits = response.getHits();
    LOGGER.info("耗时：" + response.getTook());
    LOGGER.info("是否超时：" + response.isTimedOut());
    LOGGER.info("总数：" + hits.getTotalHits());
    LOGGER.info("maxScore：" + hits.getMaxScore());
    LOGGER.info("hits =======================>>");
    for (SearchHit hit : hits) {
        // 4. 输出数据
        LOGGER.info(hit.getSourceAsString());
    }
    LOGGER.info("<<========================");
}

4.3.2.4 分页查询—-builder.from(起始值)+builder.size(页量)

/**
 * 5. 分页查询
 *
 * builder.from(起始值);   from = (pageNo-1) * size
 * builder.size(页量);
 *
 * @param restHighLevelClient   ES客户端
 */
private static void getDocByPage(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建搜索请求对象
    SearchRequest request = new SearchRequest("car");
    // 2.******构建查询请求体******
    SearchSourceBuilder builder = new SearchSourceBuilder();
    builder.query(QueryBuilders.matchAllQuery());
    builder.from(3);    // from = (pageNo-1) * pageSize
    builder.size(2);
    request.source(builder);
    // 3. 发送请求，接收响应
    SearchResponse response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
    SearchHits hits = response.getHits();
    LOGGER.info("耗时：" + response.getTook());
    LOGGER.info("是否超时：" + response.isTimedOut());
    LOGGER.info("总数：" + hits.getTotalHits());
    LOGGER.info("maxScore：" + hits.getMaxScore());
    LOGGER.info("hits =======================>>");
    for (SearchHit hit : hits) {
        // 4. 输出数据
        LOGGER.info(hit.getSourceAsString());
    }
    LOGGER.info("<<========================");
}

4.3.2.5 排序查询—-builder.sort(“字段”, SortOrder.DESC/ASC)

text字段不支持聚合和排序

/**
 * 6. 排序查询
 * 
 * builder.sort("字段", SortOrder.DESC/ASC);
 * 
 * @param restHighLevelClient   ES客户端
 */
private static void getDocBySort(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建搜索请求对象
    SearchRequest request = new SearchRequest("car");
    // 2.******构建查询请求体******
    SearchSourceBuilder builder = new SearchSourceBuilder();
    builder.query(QueryBuilders.matchAllQuery());
    builder.sort("price", SortOrder.DESC);
    request.source(builder);
    // 3. 发送请求，接收响应
    SearchResponse response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
    SearchHits hits = response.getHits();
    LOGGER.info("耗时：" + response.getTook());
    LOGGER.info("是否超时：" + response.isTimedOut());
    LOGGER.info("总数：" + hits.getTotalHits());
    LOGGER.info("maxScore：" + hits.getMaxScore());
    LOGGER.info("hits =======================>>");
    for (SearchHit hit : hits) {
        // 4. 输出数据
        LOGGER.info(hit.getSourceAsString());
    }
    LOGGER.info("<<========================");
}

4.3.2.6 过滤字段查询—-builder.fetchSource(includes,excludes)

/**
 * 7. 过滤字段查询 --- builder.fetchSource(includes,excludes);
 *
 * @param restHighLevelClient   ES客户端
 */
private static void getDocByIncludeAndExclude(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建搜索请求对象
    SearchRequest request = new SearchRequest("car");
    // 2.******构建查询请求体******
    SearchSourceBuilder builder = new SearchSourceBuilder();
    String[] includes = {"name"};
    //String[] excludes = {"price"};
    builder.fetchSource(includes,new String[]{});
    request.source(builder);
    // 3. 发送请求，接收响应
    SearchResponse response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
    SearchHits hits = response.getHits();
    LOGGER.info("耗时：" + response.getTook());
    LOGGER.info("是否超时：" + response.isTimedOut());
    LOGGER.info("总数：" + hits.getTotalHits());
    LOGGER.info("maxScore：" + hits.getMaxScore());
    LOGGER.info("hits =======================>>");
    for (SearchHit hit : hits) {
        // 4. 输出数据
        LOGGER.info(hit.getSourceAsString());
    }
    LOGGER.info("<<========================");
}

4.3.2.7 组合查询—-boolQuery()

/**
 * 8. 组合查询 --- boolQuery()
 *
 * @param restHighLevelClient   ES客户端
 */
private static void getDocByBool(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建搜索请求对象
    SearchRequest request = new SearchRequest("car");
    // 2.******构建查询请求体******
    SearchSourceBuilder builder = new SearchSourceBuilder();
    BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
    boolQueryBuilder.must(QueryBuilders.matchQuery("name", "bmw"));
    boolQueryBuilder.must(QueryBuilders.matchQuery("price", 300000));
    //boolQueryBuilder.mustNot(QueryBuilders.matchQuery("price", 300000));
    //boolQueryBuilder.should(QueryBuilders.matchQuery("price", 300000));
    builder.query(boolQueryBuilder);
    request.source(builder);
    // 3. 发送请求，接收响应
    SearchResponse response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
    SearchHits hits = response.getHits();
    LOGGER.info("耗时：" + response.getTook());
    LOGGER.info("是否超时：" + response.isTimedOut());
    LOGGER.info("总数：" + hits.getTotalHits());
    LOGGER.info("maxScore：" + hits.getMaxScore());
    LOGGER.info("hits =======================>>");
    for (SearchHit hit : hits) {
        // 4. 输出数据
        LOGGER.info(hit.getSourceAsString());
    }
    LOGGER.info("<<========================");
}

4.3.2.8 范围查询—-rangeQuery(“字段”)

/**
 * 9. 范围查询 --- rangeQuery("字段")
 *
 * @param restHighLevelClient   ES客户端
 */
private static void getDocByRange(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建搜索请求对象
    SearchRequest request = new SearchRequest("car");
    // 2.******构建查询请求体******
    SearchSourceBuilder builder = new SearchSourceBuilder();
    RangeQueryBuilder rangeQueryBuilder = QueryBuilders.rangeQuery("price");
    rangeQueryBuilder.gte(300000);
    rangeQueryBuilder.lte(500000);
    builder.query(rangeQueryBuilder);
    request.source(builder);
    // 3. 发送请求，接收响应
    SearchResponse response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
    SearchHits hits = response.getHits();
    LOGGER.info("耗时：" + response.getTook());
    LOGGER.info("是否超时：" + response.isTimedOut());
    LOGGER.info("总数：" + hits.getTotalHits());
    LOGGER.info("maxScore：" + hits.getMaxScore());
    LOGGER.info("hits =======================>>");
    for (SearchHit hit : hits) {
        // 4. 输出数据
        LOGGER.info(hit.getSourceAsString());
    }
    LOGGER.info("<<========================");
}

4.3.2.9 纠错查询—-fuzzyQuery(“字段”, “值”).fuzziness(Fuzziness.ONE/TOW/AUTO)

/**
 * 10. 纠错查询 --- fuzzyQuery("字段", "值").fuzziness(Fuzziness.ONE/TOW/AUTO);   //fuzziness()设置容忍错几个字符
 *
 * @param restHighLevelClient   ES客户端
 */
private static void getDocByFuzzy(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建搜索请求对象
    SearchRequest request = new SearchRequest("car");
    // 2.******构建查询请求体******
    SearchSourceBuilder builder = new SearchSourceBuilder();
    FuzzyQueryBuilder fuzzyQueryBuilder = QueryBuilders.fuzzyQuery("name", "bba").fuzziness(Fuzziness.TWO);   //fuzziness()设置容忍错几个字符
    builder.query(fuzzyQueryBuilder);
    request.source(builder);
    // 3. 发送请求，接收响应
    SearchResponse response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
    SearchHits hits = response.getHits();
    LOGGER.info("耗时：" + response.getTook());
    LOGGER.info("是否超时：" + response.isTimedOut());
    LOGGER.info("总数：" + hits.getTotalHits());
    LOGGER.info("maxScore：" + hits.getMaxScore());
    LOGGER.info("hits =======================>>");
    for (SearchHit hit : hits) {
        // 4. 输出数据
        LOGGER.info(hit.getSourceAsString());
    }
    LOGGER.info("<<========================");
}

4.3.2.10 高亮查询—-HighlightBuilder

/**
 * 11. 高亮查询（前提是有搜索关键词，即条件查询）
 * 
 * HighlightBuilder.filed("字段")
 * HighlightBuilder.pretTags("前缀")
 * HighlightBuilder.posttTags("后缀")
 * @param restHighLevelClient   ES客户端
 */
private static void getDocByHighlight(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建搜索请求对象
    SearchRequest request = new SearchRequest("car");
    // 2.******构建查询请求体******
    SearchSourceBuilder builder = new SearchSourceBuilder();
    // 2.1 首先条件查询
    QueryBuilder queryBuilder = QueryBuilders.termQuery("name","bmw");
    // 2.2 构建高亮字段及前后缀
    HighlightBuilder highlightBuilder = new HighlightBuilder();
    highlightBuilder.field("name");
    highlightBuilder.preTags("<font color='red'>");
    highlightBuilder.postTags("</font>");
    // 2.3 设置查询方式、高亮对象
    builder.query(queryBuilder);
    builder.highlighter(highlightBuilder);
    // 2.4 交给request
    request.source(builder);
    // 3. 发送请求，接收响应
    SearchResponse response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
    SearchHits hits = response.getHits();
    LOGGER.info("耗时：" + response.getTook());
    LOGGER.info("是否超时：" + response.isTimedOut());
    LOGGER.info("总数：" + hits.getTotalHits());
    LOGGER.info("maxScore：" + hits.getMaxScore());
    LOGGER.info("hits =======================>>");
    for (SearchHit hit : hits) {
        // 4. 输出数据
        LOGGER.info(hit.getSourceAsString());
        // 4.1 获取高亮字段
        LOGGER.info(hit.getHighlightFields());
    }
    LOGGER.info("<<========================");
}

4.3.2.11 聚合统计查询—-AggregationBuilders.max(“聚合名称”)|min()|count()|avg()|…|.field(“聚合字段”)

text字段不支持聚合和排序

/**
 * 12. 聚合统计查询------AggregationBuilders.max("聚合名称")|min()|count()|avg()|...|.field("price")
 *
 * @param restHighLevelClient   ES客户端
 */
private static void getDocByAgg(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建搜索请求对象
    SearchRequest request = new SearchRequest("car");
    // 2.******构建查询请求体******
    SearchSourceBuilder builder = new SearchSourceBuilder();
    MaxAggregationBuilder maxAggregationBuilder = AggregationBuilders.max("maxPrice").field("price");
    builder.aggregation(maxAggregationBuilder);
    request.source(builder);
    // 3. 发送请求，接收响应
    SearchResponse response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
    SearchHits hits = response.getHits();
    // 4. ******解析聚合统计结果******
    Aggregations aggregations = response.getAggregations();
    ParsedMax parsedMax = aggregations.get("maxPrice");
    LOGGER.info("耗时：" + response.getTook());
    LOGGER.info("是否超时：" + response.isTimedOut());
    LOGGER.info("总数：" + hits.getTotalHits());
    LOGGER.info("maxScore：" + hits.getMaxScore());
    LOGGER.info("统计结果：" + parsedMax.getValueAsString());
    LOGGER.info("hits =======================>>");
    for (SearchHit hit : hits) {
        // 4. 输出数据
        LOGGER.info(hit.getSourceAsString());
    }
    LOGGER.info("<<========================");
}

4.3.2.12 分组统计查询—-AggregationBuilders.terms(“分组名称”).field(“分组字段”)

text字段不支持聚合和排序

/**
 * 13. 分组统计查询（注意：text字段不能做分组）--- AggregationBuilders.terms("分组名称").field("分组字段")
 *
 * @param restHighLevelClient   ES客户端
 */
private static void getDocByAgg2(RestHighLevelClient restHighLevelClient) throws IOException {
    // 1. 创建搜索请求对象
    SearchRequest request = new SearchRequest("car");
    // 2.******构建查询请求体******
    SearchSourceBuilder builder = new SearchSourceBuilder();
    TermsAggregationBuilder termsAggregationBuilder = AggregationBuilders.terms("name_groupby").field("name");
    builder.aggregation(termsAggregationBuilder);
    request.source(builder);
    // 3. 发送请求，接收响应
    SearchResponse response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
    SearchHits hits = response.getHits();
    // 4. 解析分组统计结果
    //搜索结果状态信息
    List<Map> result=new ArrayList<>();
    Aggregations aggregations = response.getAggregations();
    Terms terms =  aggregations.get("name_groupby");
    for(Terms.Bucket buck : terms.getBuckets()) {
        Map map=new HashMap();
        String[] arr= buck.getKeyAsString().split("#");
        map.put("module",arr[0].replace("[","").replace("]",""));
        map.put("user_id",arr[1].replace("[","").replace("]",""));
        //取子聚合
        ParsedValueCount averageBalance = buck.getAggregations().get("count");
        map.put("count",averageBalance.getValue());
        result.add(map);
    }
    LOGGER.info("耗时：" + response.getTook());
    LOGGER.info("是否超时：" + response.isTimedOut());
    LOGGER.info("总数：" + hits.getTotalHits());
    LOGGER.info("maxScore：" + hits.getMaxScore());
    LOGGER.info("分组统计结果：" + result.toString());
    LOGGER.info("hits =======================>>");
    for (SearchHit hit : hits) {
        // 4. 输出数据
        LOGGER.info(hit.getSourceAsString());
    }
    LOGGER.info("<<========================");
}

ElasticSearch

七、ES的 Java API

1. 依赖

2. 客户端

3. 索引

3.1 创建—-CreateIndexRequest

3.2 查询

3.2.1 查询单个索引—-GetIndexRequest

3.2.2 查询全部索引—-GetAliasesRequest

3.3 删除—-DeleteIndexRequest

4. 文档

4.1 新增

4.1.1 单文档新增—-IndexRequest

4.1.2 批量新增—-BulkRequest

4.2 修改—-UpdateRequest

4.3 删除

4.3.1 主键删除—-DeleteRequest

4.3.2 批量删除—-BulkRequest

4.4 查询

4.3.1 主键查询—-GetRequest

4.3.2 高级查询—-SearchRequest

4.3.2.1 全量查询—-matchAllQuery()

4.3.2.2 条件查询—-termQuery(“字段”, “值”)

4.3.2.3 通配符查询—-wildcardQuery(“字段”, “值“)

4.3.2.4 分页查询—-builder.from(起始值)+builder.size(页量)

4.3.2.5 排序查询—-builder.sort(“字段”, SortOrder.DESC/ASC)

4.3.2.6 过滤字段查询—-builder.fetchSource(includes,excludes)

4.3.2.7 组合查询—-boolQuery()

4.3.2.8 范围查询—-rangeQuery(“字段”)

4.3.2.9 纠错查询—-fuzzyQuery(“字段”, “值”).fuzziness(Fuzziness.ONE/TOW/AUTO)

4.3.2.10 高亮查询—-HighlightBuilder

4.3.2.11 聚合统计查询—-AggregationBuilders.max(“聚合名称”)|min()|count()|avg()|…|.field(“聚合字段”)

4.3.2.12 分组统计查询—-AggregationBuilders.terms(“分组名称”).field(“分组字段”)