【ElasticSearch】之常用 JavaAPI

女爷i 2022-09-06 10:19 243阅读 0赞

# 目录： #

*  1、引入依赖
 *  2、创建索引
 *  3、查询索引
 *  4、删除索引
 *  5、添加文档数据
 *  6、修改文档数据
 *  7、查询文档数据
 *  8、删除文档数据
 *  9、批量插入数据
 *  10、批量删除数据
 *  11、匹配查询
 *  12、条件查询
 *  13、分页查询
 *  14、查询排序
 *  15、过滤字段
 *  16、组合查询
 *  17、范围查询
 *  18、模糊查询
 *  19、高亮查询
 *  20、聚合查询
 *  21、分组查询

## 1、引入依赖 ##

--------------------

<dependency>
        <groupId>org.elasticsearch</groupId>
        <artifactId>elasticsearch</artifactId>
        <version>7.8.0</version>
    </dependency>
    
    
    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>elasticsearch-rest-high-level-client</artifactId>
        <version>7.8.0</version>
    </dependency>

## 2、创建索引 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建索引
    CreateIndexRequest request = new CreateIndexRequest("user");
    CreateIndexResponse response = esClient.indices().create(request, RequestOptions.DEFAULT);
    
    // 打印创建结果
    System.out.println("索引创建结果：" + response.isAcknowledged());
    
    // 关闭客户端
    esClient.close();

## 3、查询索引 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 查询索引
    GetIndexRequest request = new GetIndexRequest("user");
    GetIndexResponse getIndexResponse = esClient.indices().get(request, RequestOptions.DEFAULT);
    
    // 打印索引信息
    System.out.println(getIndexResponse.getAliases());
    System.out.println(getIndexResponse.getMappings());
    System.out.println(getIndexResponse.getSettings());
    
    // 关闭客户端
    esClient.close();

## 4、删除索引 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 删除索引
    DeleteIndexRequest request = new DeleteIndexRequest("user");
    AcknowledgedResponse response = esClient.indices().delete(request, RequestOptions.DEFAULT);
    
    // 打印结果
    System.out.println("删除结果：" + response.isAcknowledged());
    
    // 关闭客户端
    esClient.close();

## 5、添加文档数据 ##

--------------------

文档数据对象：

@Data
    @Accessors(chain = true)
    public class User { 
        
        private String name;
        
        private String sex;
        
        private Integer age;
        
    }

添加文档数据：

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建添加文档数据请求
    // index()指定要添加数据的索引，id()指定文档ID
    IndexRequest request = new IndexRequest();
    request.index("user").id("1001");
    
    // 创建文档数据对象
    User user = new User().setName("wang").setSex("man").setAge(18);
    
    // 向ES插入数据，对象需要转换成JSON格式
    // source()指定文档数据对象
    request.source(JSON.toJSONString(user), XContentType.JSON);
    IndexResponse response = esClient.index(request, RequestOptions.DEFAULT);
    
    // 打印结果
    System.out.println("数据添加结果：" + response.getResult());
    
    // 关闭客户端
    esClient.close();

**注意：** 索引操作使用的是 `indices()` 方法，文档数据使用的 `index()` 方法，表示对具体索引的操作。

## 6、修改文档数据 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建修改文档请求
    // index()指定要添加数据的索引，id()指定文档ID，doc()指定要修改的字段
    UpdateRequest request = new UpdateRequest();
    request.index("user").id("1001");
    request.doc(XContentType.JSON, "sex", "woman");
    
    // 修改数据
    UpdateResponse response = esClient.update(request, RequestOptions.DEFAULT);
    
    // 打印结果
    System.out.println("数据修改结果：" + response.getResult());
    
    // 关闭客户端
    esClient.close();

## 7、查询文档数据 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建查询文档请求
    // index()指定要添加数据的索引，id()指定文档ID
    GetRequest request = new GetRequest();
    request.index("user").id("1001");
    
    // 向ES查询数据
    GetResponse response = esClient.get(request, RequestOptions.DEFAULT);
    
    // 打印结果：结果存储在 source 中
    System.out.println("文档数据内容：" + response.getSourceAsString());
    
    // 关闭客户端
    esClient.close();

## 8、删除文档数据 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建删除文档请求
    // index()指定要添加数据的索引，id()指定文档ID
    DeleteRequest request = new DeleteRequest();
    request.index("user").id("1001");
    
    // 删除数据
    DeleteResponse response = esClient.delete(request, RequestOptions.DEFAULT);
    
    // 打印结果
    System.out.println("数据删除结果：" + response.toString());
    
    // 关闭客户端
    esClient.close();

## 9、批量插入数据 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建批量添加请求
    BulkRequest bulkRequest = new BulkRequest();
    bulkRequest.add(new IndexRequest().index("user").id("1001")
            .source(XContentType.JSON, "name", "wang", "sex", "man", "age", 18));
    bulkRequest.add(new IndexRequest().index("user").id("1002")
            .source(XContentType.JSON, "name", "andy", "sex", "man", "age", 19));
    bulkRequest.add(new IndexRequest().index("user").id("1003")
            .source(XContentType.JSON, "name", "lucy", "sex", "woman", "age", 20));
    
    // 批量添加数据
    BulkResponse response = esClient.bulk(bulkRequest, RequestOptions.DEFAULT);
    
    // 打印结果：took表示花费的时间，items表示数据项
    System.out.println(response.getTook());
    System.out.println(Arrays.toString(response.getItems()));
    
    // 关闭客户端
    esClient.close();

## 10、批量删除数据 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建删除请求
    BulkRequest bulkRequest = new BulkRequest();
    bulkRequest.add(new DeleteRequest().index("user").id("1001"));
    bulkRequest.add(new DeleteRequest().index("user").id("1002"));
    bulkRequest.add(new DeleteRequest().index("user").id("1003"));
    
    // 批量删除数据
    BulkResponse response = esClient.bulk(bulkRequest, RequestOptions.DEFAULT);
    
    // 关闭客户端
    esClient.close();

## 11、匹配查询 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建检索请求
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("user");
    
    // 创建匹配条件，使用 matchAllQuery()匹配所有数据
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    sourceBuilder.query(QueryBuilders.QueryBuilders.matchQuery("age", "18"));
    
    // 发送检索请求
    searchRequest.source(sourceBuilder);
    SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
    
    // 遍历查询结果
    SearchHits hits = response.getHits();
    for (SearchHit hit : hits) { 
        System.out.println(hit.getSourceAsString());
    }
    
    // 关闭客户端
    esClient.close();

## 12、条件查询 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建检索请求
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("user");
    
    // 创建检索请求
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("user");
    
    // 创建检索条件
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    sourceBuilder.query(QueryBuilders.termQuery("age", "18"));
    
    // 发送检索请求
    searchRequest.source(sourceBuilder);
    SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
    
    // 遍历查询结果
    SearchHits hits = response.getHits();
    for (SearchHit hit : hits) { 
        System.out.println(hit.getSourceAsString());
    }
    
    // 关闭客户端
    esClient.close();

## 13、分页查询 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建检索请求
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("user");
    
    // 创建检索条件
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    sourceBuilder.query(QueryBuilders.matchAllQuery());
    sourceBuilder.from(1);
    sourceBuilder.size(2);
    
    // 发送检索请求
    searchRequest.source(sourceBuilder);
    SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
    
    // 遍历查询结果
    SearchHits hits = response.getHits();
    for (SearchHit hit : hits) { 
        System.out.println(hit.getSourceAsString());
    }
    
    // 关闭客户端
    esClient.close();

## 14、查询排序 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建检索请求
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("user");
    
    // 创建检索条件
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    sourceBuilder.query(QueryBuilders.matchAllQuery());
    sourceBuilder.sort("age", SortOrder.DESC);
    
    // 发送检索请求
    searchRequest.source(sourceBuilder);
    SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
    
    // 遍历查询结果
    SearchHits hits = response.getHits();
    for (SearchHit hit : hits) { 
        System.out.println(hit.getSourceAsString());
    }
    
    // 关闭客户端
    esClient.close();

## 15、过滤字段 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建检索请求
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("user");
    
    // 创建检索条件
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    sourceBuilder.query(QueryBuilders.matchAllQuery());
    String[] excludes = { "age"};
    String[] includes = { "name"};
    sourceBuilder.fetchSource(includes, excludes);
    
    // 发送检索请求
    searchRequest.source(sourceBuilder);
    SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
    
    // 遍历查询结果
    SearchHits hits = response.getHits();
    for (SearchHit hit : hits) { 
        System.out.println(hit.getSourceAsString());
    }
    
    // 关闭客户端
    esClient.close();

## 16、组合查询 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建检索请求
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("user");
    
    // 创建检索条件
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
    boolQuery.must(QueryBuilders.matchQuery("age", 18));
    boolQuery.mustNot(QueryBuilders.matchQuery("sex", "woman"));
    sourceBuilder.query(boolQuery);
    
    // 发送检索请求
    searchRequest.source(sourceBuilder);
    SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
    
    // 遍历查询结果
    SearchHits hits = response.getHits();
    for (SearchHit hit : hits) { 
        System.out.println(hit.getSourceAsString());
    }
    
    // 关闭客户端
    esClient.close();

## 17、范围查询 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建检索请求
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("user");
    
    // 创建检索条件
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    RangeQueryBuilder rangeQuery = QueryBuilders.rangeQuery("age");
    rangeQuery.gte(18);
    rangeQuery.lt(20);
    sourceBuilder.query(rangeQuery);
    
    // 发送检索请求
    searchRequest.source(sourceBuilder);
    SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
    
    // 遍历查询结果
    SearchHits hits = response.getHits();
    for (SearchHit hit : hits) { 
        System.out.println(hit.getSourceAsString());
    }
    
    // 关闭客户端
    esClient.close();

## 18、模糊查询 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建检索请求
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("user");
    
    // 创建检索条件
    // fuzzyQuery()创建模糊查询字段值，fuzziness()表示允许相差多少个字符
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    sourceBuilder.query(QueryBuilders.fuzzyQuery("name", "wang").fuzziness(Fuzziness.ONE));
    
    // 发送检索请求
    searchRequest.source(sourceBuilder);
    SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
    
    // 遍历查询结果
    SearchHits hits = response.getHits();
    for (SearchHit hit : hits) { 
        System.out.println(hit.getSourceAsString());
    }
    
    // 关闭客户端
    esClient.close();

## 19、高亮查询 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建检索请求
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("user");
    
    // 创建检索条件
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    sourceBuilder.query(QueryBuilders.matchQuery("name", "wang"));
    HighlightBuilder highlighter = new HighlightBuilder();
    highlighter.field("name");
    highlighter.preTags("<font color='red'>");
    highlighter.postTags("</font>");
    sourceBuilder.highlighter(highlighter);
    
    // 发送检索请求
    searchRequest.source(sourceBuilder);
    SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
    
    // 打印结果
    System.out.println(response.toString());
    
    // 关闭客户端
    esClient.close();

## 20、聚合查询 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建检索请求
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("user");
    
    // 创建聚合查询条件：maxAge为查询结果名称，随意起
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    sourceBuilder.aggregation(AggregationBuilders.max("maxAge").field("age"));
    
    // 发送检索请求
    searchRequest.source(sourceBuilder);
    SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
    
    // 打印结果
    System.out.println(response.toString());
    
    // 关闭客户端
    esClient.close();

## 21、分组查询 ##

--------------------

// 创建 ES 客户端
    RestHighLevelClient esClient = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    // 创建检索请求
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("user");
    
    // 创建分组查询条件：ageGroup为查询结果名称，可随意起；filed()指定按按个字段进行分组
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    sourceBuilder.aggregation(AggregationBuilders.terms("ageGroup").field("age"));
    
    // 发送检索请求
    searchRequest.source(sourceBuilder);
    SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
    
    // 打印结果
    System.out.println(response.toString());
    
    // 关闭客户端
    esClient.close();