Elasticsearch 7.x入门学习-Java API操作

Code0cean2024-07-25 14:23

1 创建项目

在idea开发工具中创建Maven项目

修改 pom 文件，增加 Maven 依赖关系

xml 复制代码 
<dependencies>
        <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>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.9</version>
        </dependency>
        <!-- junit 单元测试 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
    </dependencies>

新建ClientTest类创建客户端对象测试是否能连接

java 复制代码 
public class ClientTest {

    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        System.out.println(client);
        client.close();
    }
}

备注：9200 端口为 Elasticsearch 的 Web 通信端口，localhost 为启动 ES 服务的主机名

执行代码，查看控制台信息，没有报错证明连接成功：

2 索引操作

通过 Java API 客户端对象对 ES 索引进行操作

2.1 创建索引

java 复制代码 
public class IndexTest {
    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        System.out.println(client);
        // 创建索引 - 请求对象
        CreateIndexRequest createIndexRequest = new CreateIndexRequest("user");
        // 发送请求，获取响应
        CreateIndexResponse createIndexResponse = client.indices().create(createIndexRequest, RequestOptions.DEFAULT);
        // 获取响应状态
        boolean acknowledged = createIndexResponse.isAcknowledged();
        System.out.println("操作状态 = " + acknowledged);
        client.close();
    }
}

执行结果：

2.2 查看索引

java 复制代码 
public class IndexTest {
    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        // 查询索引 - 请求对象
        GetIndexRequest request = new GetIndexRequest("user");
        // 发送请求，获取响应
        GetIndexResponse response = client.indices().get(request, RequestOptions.DEFAULT);
        System.out.println("aliases:" + response.getAliases());
        System.out.println("mappings:" + response.getMappings());
        System.out.println("settings:" + response.getSettings());
        client.close();
    }
}

执行结果：

2.3 删除索引

java 复制代码 
public class IndexTest {
    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
       DeleteIndexRequest deleteIndexRequest = new DeleteIndexRequest("user");
       // 发送请求，获取响应
       AcknowledgedResponse deleteResponse = client.indices().delete(deleteIndexRequest, RequestOptions.DEFAULT);
       System.out.println("操作状态 = " + deleteResponse.isAcknowledged());
       client.close();
    }
}

删除索引执行完成后再次查看索引会报错

3 文档操作

3.1 新增文档

创建数据模型实体类User

java 复制代码 
public class User {

    private String name;
    private Integer age;
    private String sex;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }
}

创建连接，创建数据添加到文档上，没有索引的话会自动创建索引并添加文档

java 复制代码 
public class DocumentTest {
    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        createDocument(client);
        System.out.println(client);
        client.close();
    }

    private static void createDocument(RestHighLevelClient client) throws IOException {
        // 新增文档 - 请求对象
        IndexRequest request = new IndexRequest();
        // 设置索引及唯一性标识
        request.index("user").id("1001");
        // 创建数据对象
        User user = new User();
        user.setName("zhangsan");
        user.setAge(30);
        user.setSex("男");
        ObjectMapper objectMapper = new ObjectMapper();
        String productJson = objectMapper.writeValueAsString(user);
        // 添加文档数据，数据格式为 JSON 格式
        request.source(productJson, XContentType.JSON);
        // 客户端发送请求，获取响应对象
        IndexResponse response = client.index(request, RequestOptions.DEFAULT);
        // 打印结果信息
        System.out.println("_index:" + response.getIndex());
        System.out.println("_id:" + response.getId());
        System.out.println("_result:" + response.getResult());
    }
}

执行结果：

3.2 查询文档

根据id查询文档示例

java 复制代码 
public class DocumentTest {
    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        searchDocument(client);
        client.close();
    }

    private static void searchDocument(RestHighLevelClient client) throws IOException {
        //1.创建请求对象
        GetRequest request = new GetRequest().index("user").id("1001");
        //2.客户端发送请求，获取响应对象
        GetResponse response = client.get(request, RequestOptions.DEFAULT);
        //3.打印结果信息
        System.out.println("_index:" + response.getIndex());
        System.out.println("_type:" + response.getType());
        System.out.println("_id:" + response.getId());
        System.out.println("source:" + response.getSourceAsString());
    }
}

执行结果：

3.3 修改文档

根据id将sex更新为"女"代码示例：

java 复制代码 
public class DocumentTest {
    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        updateDocument(client);
        client.close();
    }

    private static void searchDocument(RestHighLevelClient client) throws IOException {
        //1.创建请求对象
        GetRequest request = new GetRequest().index("user").id("1001");
        //2.客户端发送请求，获取响应对象
        GetResponse response = client.get(request, RequestOptions.DEFAULT);
        //3.打印结果信息
        System.out.println("_index:" + response.getIndex());
        System.out.println("_type:" + response.getType());
        System.out.println("_id:" + response.getId());
        System.out.println("source:" + response.getSourceAsString());
    }

    private static void updateDocument(RestHighLevelClient client) throws IOException {
        searchDocument(client);
        UpdateRequest updateRequest = new UpdateRequest();
        updateRequest.index("user").id("1001");
        updateRequest.doc(XContentType.JSON, "sex", "女");
        UpdateResponse response = client.update(updateRequest, RequestOptions.DEFAULT);
        System.out.println("_index:" + response.getIndex());
        System.out.println("_id:" + response.getId());
        System.out.println("_result:" + response.getResult());
        searchDocument(client);
    }
}

执行结果：

3.4 删除文档

根据id删除文档

java 复制代码 
public class DocumentTest {
    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        deleteDocument(client);
        client.close();
    }

    private static void deleteDocument(RestHighLevelClient client) throws IOException {
        //查看文档
        searchDocument(client);
        //删除文档
        DeleteRequest deleteRequest = new DeleteRequest().index("user").id("1001");
        DeleteResponse deleteResponse = client.delete(deleteRequest, RequestOptions.DEFAULT);
        System.out.println(deleteResponse.toString());
        //查看文档
        searchDocument(client);

    }

    private static void searchDocument(RestHighLevelClient client) throws IOException {
        //1.创建请求对象
        GetRequest request = new GetRequest().index("user").id("1001");
        //2.客户端发送请求，获取响应对象
        GetResponse response = client.get(request, RequestOptions.DEFAULT);
        //3.打印结果信息
        System.out.println("_index:" + response.getIndex());
        System.out.println("_type:" + response.getType());
        System.out.println("_id:" + response.getId());
        System.out.println("source:" + response.getSourceAsString());
    }
}

执行结果：

3.5 批量操作

java 复制代码 
public class BatchTest {
    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        //创建批量新增请求对象
        BulkRequest request = new BulkRequest();
        request.add(new IndexRequest().index("user").id("1001").source(XContentType.JSON, "name", "张三"));
        request.add(new IndexRequest().index("user").id("1002").source(XContentType.JSON, "name", "李四"));
        request.add(new IndexRequest().index("user").id("1003").source(XContentType.JSON, "name", "王五"));
        BulkResponse bulkResponse = client.bulk(request, RequestOptions.DEFAULT);
        //打印结果信息
        //打印结果信息
        System.out.println("took:" + bulkResponse.getTook());
        System.out.println("items:" + bulkResponse.getItems());
        client.close();
    }
}

执行结果：

批量删除操作

批量插入文档后再批量删除文档

java 复制代码 
public class BatchTest {
    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        //创建批量新增请求对象
        BulkRequest request = new BulkRequest();
        request.add(new IndexRequest().index("user").id("1001").source(XContentType.JSON, "name", "张三"));
        request.add(new IndexRequest().index("user").id("1002").source(XContentType.JSON, "name", "李四"));
        request.add(new IndexRequest().index("user").id("1003").source(XContentType.JSON, "name", "王五"));
        BulkResponse bulkResponse = client.bulk(request, RequestOptions.DEFAULT);
        //打印结果信息
        System.out.println("took:" + bulkResponse.getTook());
        System.out.println("items:" + bulkResponse.getItems());

        searchDocument(client);
        BulkRequest deleteRequest = new BulkRequest();
        deleteRequest.add(new DeleteRequest().index("user").id("1001"));
        deleteRequest.add(new DeleteRequest().index("user").id("1002"));
        BulkResponse deleteResponse = client.bulk(deleteRequest, RequestOptions.DEFAULT);
        //打印结果信息
        System.out.println("took:" + deleteResponse.getTook());
        System.out.println("items:" + deleteResponse.getItems());

        searchDocument(client);
        client.close();
    }

    private static void searchDocument(RestHighLevelClient client) throws IOException {
        //1.创建请求对象
        GetRequest getRequest = new GetRequest().index("user").id("1001");
        //2.客户端发送请求，获取响应对象
        GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);
        //3.打印结果信息
        System.out.println("_index:" + getResponse.getIndex());
        System.out.println("_type:" + getResponse.getType());
        System.out.println("_id:" + getResponse.getId());
        System.out.println("source:" + getResponse.getSourceAsString());
        GetRequest getRequest2 = new GetRequest().index("user").id("1002");
        //2.客户端发送请求，获取响应对象
        GetResponse getResponse2 = client.get(getRequest2, RequestOptions.DEFAULT);
        //3.打印结果信息
        System.out.println("_index:" + getResponse2.getIndex());
        System.out.println("_type:" + getResponse2.getType());
        System.out.println("_id:" + getResponse2.getId());
        System.out.println("source:" + getResponse2.getSourceAsString());
    }
}

执行结果：

4 高级查询

4.1 请求体查询

4.1.1 查询所有索引数据

查询所有索引数据,代码示例

java 复制代码 
public class SearchTest {

    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        searchAll(client);
        client.close();
    }


    private static void searchAll(RestHighLevelClient client) throws IOException {
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        //构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        //查询所有数据
        sourceBuilder.query(QueryBuilders.matchAllQuery());
        request.source(sourceBuilder);
        SearchResponse searchResponse = client.search(request, RequestOptions.DEFAULT);
        //查询匹配
        SearchHits hits = searchResponse.getHits();
        System.out.println("took:" + searchResponse.getTook());
        System.out.println("timeout:" + searchResponse.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
    }
}

查询结果：

4.1.2 term查询

term查询，查询条件为关键字,代码示例：

java 复制代码 
public class SearchTest {

    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        termQuery(client);
        client.close();
    }

    private static void termQuery(RestHighLevelClient client) throws IOException {
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        //构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        //查询所有数据
        sourceBuilder.query(QueryBuilders.termQuery("age", 30));
        request.source(sourceBuilder);
        SearchResponse searchResponse = client.search(request, RequestOptions.DEFAULT);
        //查询匹配
        SearchHits hits = searchResponse.getHits();
        System.out.println("took:" + searchResponse.getTook());
        System.out.println("timeout:" + searchResponse.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
    }
}

执行结果：

4.1.3 分页查询
java 复制代码 
public class SearchTest {

    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        pageQuery(client);
        client.close();
    }
    
    private static void pageQuery(RestHighLevelClient client) throws IOException {
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        //构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        //查询所有数据
        sourceBuilder.query(QueryBuilders.matchAllQuery());
        // 当前页其实索引(第一条数据的顺序号)
        sourceBuilder.from(2);
        //每页显示多少条
        sourceBuilder.size(2);
        request.source(sourceBuilder);
        SearchResponse searchResponse = client.search(request, RequestOptions.DEFAULT);
        //查询匹配
        SearchHits hits = searchResponse.getHits();
        System.out.println("took:" + searchResponse.getTook());
        System.out.println("timeout:" + searchResponse.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
    }
}

执行结果：

4.1.2 数据排序

数据排序代码示例：

java 复制代码 
public class SearchTest {

    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        sort(client);
        client.close();
    }




    private static void sort(RestHighLevelClient client) throws IOException {
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        //构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        //查询所有数据
        sourceBuilder.query(QueryBuilders.matchAllQuery());
        sourceBuilder.sort("age", SortOrder.ASC);
        request.source(sourceBuilder);
        SearchResponse searchResponse = client.search(request, RequestOptions.DEFAULT);
        //查询匹配
        SearchHits hits = searchResponse.getHits();
        System.out.println("took:" + searchResponse.getTook());
        System.out.println("timeout:" + searchResponse.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
    }

}

执行结果

4.1.2 过滤字段

代码示例：

java 复制代码 
public class SearchTest {

    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        fetchSource(client);
        client.close();
    }

    private static void fetchSource(RestHighLevelClient client) throws IOException {
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        //构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        //查询所有数据
        sourceBuilder.query(QueryBuilders.matchAllQuery());
        //查询字段过滤
        String[] excludes = {};
        String[] includes = {"name", "age"};
        sourceBuilder.fetchSource(includes, excludes);

        request.source(sourceBuilder);
        SearchResponse searchResponse = client.search(request, RequestOptions.DEFAULT);
        //查询匹配
        SearchHits hits = searchResponse.getHits();
        System.out.println("took:" + searchResponse.getTook());
        System.out.println("timeout:" + searchResponse.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
    }
}

执行结果：

4.1.2 Bool查询
java 复制代码 
public class SearchTest {

    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));![在这里插入图片描述](https://img-blog.csdnimg.cn/direct/f61e9a465dba47b69caf62250b594da0.png)

        boolQuery(client);
        client.close();
    }

    private static void boolQuery(RestHighLevelClient client) throws IOException {
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        //构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        //查询所有数据
        BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
        boolQueryBuilder.must(QueryBuilders.matchQuery("age", 30));
        boolQueryBuilder.mustNot(QueryBuilders.matchQuery("name", "zhangsan"));
        boolQueryBuilder.should(QueryBuilders.matchQuery("set", "男"));
        sourceBuilder.query(boolQueryBuilder);

        request.source(sourceBuilder);
        SearchResponse searchResponse = client.search(request, RequestOptions.DEFAULT);
        //查询匹配
        SearchHits hits = searchResponse.getHits();
        System.out.println("took:" + searchResponse.getTook());
        System.out.println("timeout:" + searchResponse.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
    }
    }

执行结果：

4.1.2 范围查询
java 复制代码 
public class SearchTest {

    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        rangeQuery(client);
        client.close();
    }

    private static void rangeQuery(RestHighLevelClient client) throws IOException {
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        //构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        RangeQueryBuilder rangeQuery = QueryBuilders.rangeQuery("age");
        //大于等于
        rangeQuery.gte(30);
        //小于等于
        rangeQuery.lte(40);
        sourceBuilder.query(rangeQuery);

        request.source(sourceBuilder);
        SearchResponse searchResponse = client.search(request, RequestOptions.DEFAULT);
        //查询匹配
        SearchHits hits = searchResponse.getHits();
        System.out.println("took:" + searchResponse.getTook());
        System.out.println("timeout:" + searchResponse.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }

    }
}

执行结果：

4.1.2 模糊查询

代码示例：

java 复制代码 
public class SearchTest {

    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        fuzzyQuery(client);
        client.close();
    }

    private static void fuzzyQuery(RestHighLevelClient client) throws IOException {
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        //构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        FuzzyQueryBuilder builder = QueryBuilders.fuzzyQuery("name", "zhangsan").fuzziness(Fuzziness.ONE);
        sourceBuilder.query(builder);

        request.source(sourceBuilder);
        SearchResponse searchResponse = client.search(request, RequestOptions.DEFAULT);
        //查询匹配
        SearchHits hits = searchResponse.getHits();
        System.out.println("took:" + searchResponse.getTook());
        System.out.println("timeout:" + searchResponse.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }

    }
    }

执行结果：

4.2 高亮查询

代码示例

java 复制代码 
public class SearchTest {

    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
        highLightQuery(client);
        client.close();
    }

    private static void highLightQuery(RestHighLevelClient client) throws IOException  {
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        //构建查询的请求体
        TermsQueryBuilder termsQueryBuilder = QueryBuilders.termsQuery("name", "zhangsan");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.query(termsQueryBuilder);
        //设置高亮字段
        HighlightBuilder highlightBuilder = new HighlightBuilder();
        highlightBuilder.preTags("<font color='red'>");//设置标签前缀
        highlightBuilder.postTags("</font>");//设置标签后缀
        highlightBuilder.field("name");//设置高亮字段
        //设置高亮构建对象
        sourceBuilder.highlighter(highlightBuilder);
        //设置请求体
        request.source(sourceBuilder);
        SearchResponse searchResponse = client.search(request, RequestOptions.DEFAULT);
        //查询匹配
        SearchHits hits = searchResponse.getHits();
        System.out.println("took:" + searchResponse.getTook());
        System.out.println("timeout:" + searchResponse.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
            //打印高亮结果
            Map<String, HighlightField> highlightFields = hit.getHighlightFields();
            System.out.println(highlightFields);
        }

    }
    }

执行结果

4.3 聚合查询

4.3.1函数使用

代码示例

java 复制代码 
public class SearchTest {

    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));

        maxQuery(client);
        client.close();
    }

    private static void maxQuery(RestHighLevelClient client) throws IOException {
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        //构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.aggregation(AggregationBuilders.max("maxAge").field("age"));
        request.source(sourceBuilder);
        SearchResponse searchResponse = client.search(request, RequestOptions.DEFAULT);
        System.out.println(searchResponse);
        //查询匹配
        SearchHits hits = searchResponse.getHits();
        System.out.println("took:" + searchResponse.getTook());
        System.out.println("timeout:" + searchResponse.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
    }
    }

执行结果：

分组统计

java 复制代码 
public class SearchTest {

    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
//        searchAll(client);
//        termQuery(client);
//        pageQuery(client);
//        sort(client);
//        fetchSource(client);
//        boolQuery(client);
//        rangeQuery(client);
//        fuzzyQuery(client);
//        highLightQuery(client);
//        maxQuery(client);
        groupByQuery(client);
        client.close();
    }


    private static void groupByQuery(RestHighLevelClient client) throws IOException {
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        //构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.aggregation(AggregationBuilders.terms("age_groupby").field("age"));
        request.source(sourceBuilder);
        SearchResponse searchResponse = client.search(request, RequestOptions.DEFAULT);
        System.out.println(searchResponse.getAggregations().get("age_groupby").getType());
        //查询匹配
        SearchHits hits = searchResponse.getHits();
        System.out.println("took:" + searchResponse.getTook());
        System.out.println("timeout:" + searchResponse.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
    }
    }

官方Java API 文档地址：

https://www.elastic.co/guide/en/elasticsearch/client/java-api-client/current/getting-started-java.html

代码地址：https://github.com/JustCoding-Hai/es-demo

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