ElasticSearch Java API 操作

1.idea创建Maven项目

2.添加依赖

修改 pom.xml 文件

<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>

3.客户端对象

创建 ES_test 类：

public class ES_test {

    public static void main(String[] args) throws IOException {
        // 创建客户端对象
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost", 9200, "http"))
        );
        // 关闭客户端连接
        client.close();
    }
}

localhost为 es服务器主机名（windows下部署，所以用localhost就可以）

9200端口为es 通信端口

执行代码：

4.ES api 操作

4.1 索引操作

4.1.1创建索引

    /**
     * 创建索引
     * @param client  客户端对象
     * @param indexName  索引名称
     * @throws IOException
     */
    public static void CreateIndex(RestHighLevelClient client,String indexName) throws IOException {
        // 创建索引 - 请求对象
        CreateIndexRequest request = new CreateIndexRequest(indexName);
        // 发送请求，获取响应
        CreateIndexResponse response = client.indices().create(request,
                RequestOptions.DEFAULT);
        boolean acknowledged = response.isAcknowledged();
        // 响应状态
        System.out.println("操作状态 = " + acknowledged);
    }

4.1.2 查看索引

    /**
     *
     * @param client 客户端对象
     * @param indexName 索引名称
     * @throws IOException
     */
    public static void GetIndex(RestHighLevelClient client,String indexName) throws IOException {
        // 查询索引 - 请求对象
        GetIndexRequest request = new GetIndexRequest(indexName);
        // 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());
    }

4.1.3 删除索引

    /**
     *
     * @param client 客户端对象
     * @param indexName 索引名称
     * @throws IOException
     */
    public static void DeleteIndex(RestHighLevelClient client,String indexName) throws IOException {
        // 删除索引 - 请求对象
        DeleteIndexRequest request = new DeleteIndexRequest(indexName);
        // 发送请求，获取响应
        AcknowledgedResponse response = client.indices().delete(request,RequestOptions.DEFAULT);
        // 操作结果
        System.out.println("操作结果 ： " + response.isAcknowledged());
    }

4.2 文档操作

创建User 类

/**
 * @author MR.Liu
 * @version 1.0
 * @data 2023-07-19 15:28
 */
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;
    }

    public User(String name, Integer age, String sex) {
        this.name = name;
        this.age = age;
        this.sex = sex;
    }

    public User() {

    }
}

4.2.1 新增文档

    public static void InsertDoc(RestHighLevelClient client,String indexName,User user,String id) 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(indexName).id(id);
        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);
        3.打印结果信息
        System.out.println("_index:" + response.getIndex());
        System.out.println("_id:" + response.getId());
        System.out.println("_result:" + response.getResult());
    }

4.2.2 修改文档

    public static  void UpdateDoc(RestHighLevelClient client,String indexName,String id,String field,Object value) throws IOException {
        // 修改文档 - 请求对象
        UpdateRequest request = new UpdateRequest();
        // 配置修改参数
        request.index(indexName).id(id);
        // 设置请求体，对数据进行修改
        request.doc(XContentType.JSON, field, value);
        // 客户端发送请求，获取响应对象
        UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
        System.out.println("_index:" + response.getIndex());
        System.out.println("_id:" + response.getId());
        System.out.println("_result:" + response.getResult());
    }

4.2.3 删除文档

    public static void DeleteDoc(RestHighLevelClient client,String indexName,String id) throws IOException {
        //创建请求对象
        DeleteRequest request = new DeleteRequest().index(indexName).id(id);
        //客户端发送请求，获取响应对象
        DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);
        //打印信息
        System.out.println(response.toString());
    }

4.2.4 批量新增文档

public static void ListInsertDoc(RestHighLevelClient client,String indexName) throws IOException {
        //创建批量新增请求对象
        BulkRequest request = new BulkRequest();
        request.add(new IndexRequest().index(indexName).id("10001").source(XContentType.JSON, "name",
                "zhangsan"));
        request.add(new IndexRequest().index(indexName).id("10002").source(XContentType.JSON, "name",
                "lisi"));
        request.add(new IndexRequest().index(indexName).id("10003").source(XContentType.JSON, "name",
                "wangwu"));
        //客户端发送请求，获取响应对象
        BulkResponse responses = client.bulk(request, RequestOptions.DEFAULT);
        //打印结果信息
        System.out.println("took:" + responses.getTook());
        System.out.println("items:" + responses.getItems());
    }

4.2.5 批量删除文档

public static void ListDeleteDoc(RestHighLevelClient client,String indexName,String ... id) throws IOException {
        //创建批量删除请求对象
        BulkRequest request = new BulkRequest();
        for (int i=0;i<id.length;i++){
            System.out.println(id[i]);
            request.add(new DeleteRequest().index(indexName).id(id[i]));
        }
        //客户端发送请求，获取响应对象
        BulkResponse responses = client.bulk(request, RequestOptions.DEFAULT);
        //打印结果信息
        System.out.println("took:" + responses.getTook());
        System.out.println("items:" + responses.getItems());
    }

4.3 高级查询

4.3.1 请求体查询

4.3.1.1 查询索引中所有文档

    public static void SelectIndexAllDoc(RestHighLevelClient client,String indexName) throws IOException {
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices(indexName);
        // 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 response = client.search(request, RequestOptions.DEFAULT);
        // 查询匹配
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.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());
        }
        System.out.println("<<========");
    }

4.3.1.2 term查询关键字

    public static void TramSelectByKeyWords(RestHighLevelClient client,String indexName) 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.query(QueryBuilders.termQuery("age", "30"));
        request.source(sourceBuilder);
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 查询匹配
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.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());
        }
        System.out.println("<<========");
    }

4.3.1.3分页查询

 public static void Paging(RestHighLevelClient client,String indexName) 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.query(QueryBuilders.matchAllQuery());
        // 分页查询
        // 当前页其实索引(第一条数据的顺序号)，from
        sourceBuilder.from(0);
        // 每页显示多少条 size
        sourceBuilder.size(2);
        request.source(sourceBuilder);
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 查询匹配
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.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());
        }
        System.out.println("<<========");
    }

4.3.1.4排序查询

public static void SortOrderAll(RestHighLevelClient client,String indexName) 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.query(QueryBuilders.matchAllQuery());
        // 排序
        sourceBuilder.sort("age", SortOrder.ASC);
        request.source(sourceBuilder);
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 查询匹配
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.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());
        }
        System.out.println("<<========");
    }

4.3.1.5 过滤字段

public static void FilterByColumn(RestHighLevelClient client,String indexName) 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.query(QueryBuilders.matchAllQuery());
        //查询字段过滤
        String[] excludes = {};
        String[] includes = {"name", "age"};
        sourceBuilder.fetchSource(includes, excludes);
        request.source(sourceBuilder);
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 查询匹配
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.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());
        }
        System.out.println("<<========");
    }

4.3.1.6 Bool查询

public static void boolSelect(RestHighLevelClient client,String indexName) 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();
        BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
        // 必须包含
        boolQueryBuilder.must(QueryBuilders.matchQuery("age", "30"));
        // 一定不含
        boolQueryBuilder.mustNot(QueryBuilders.matchQuery("name", "zhangsan"));
        // 可能包含
        boolQueryBuilder.should(QueryBuilders.matchQuery("sex", "男"));
        sourceBuilder.query(boolQueryBuilder);
        request.source(sourceBuilder);
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 查询匹配
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.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());
        }
        System.out.println("<<========");
    }

4.3.1.7 范围查询

public static void RangeSelect(RestHighLevelClient client,String indexName) 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 response = client.search(request, RequestOptions.DEFAULT);
        // 查询匹配
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.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());
        }
        System.out.println("<<========");
    }

4.3.1.8 模糊查询

public static void VagueSelect(RestHighLevelClient client,String indexName) 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.query(QueryBuilders.fuzzyQuery("name","zhangsan").fuzziness(Fuzziness.ONE));
        request.source(sourceBuilder);
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 查询匹配
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.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());
        }
        System.out.println("<<========");
    }

4.3.2 高亮查询

public static void HighlightSelect(RestHighLevelClient client,String indexName) throws IOException {
        // 高亮查询
        SearchRequest request = new SearchRequest().indices("student");
        //2.创建查询请求体构建器
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        //构建查询方式：高亮查询
        TermsQueryBuilder termsQueryBuilder = QueryBuilders.termsQuery("name","zhangsan");
        //设置查询方式
        sourceBuilder.query(termsQueryBuilder);
        //构建高亮字段
        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);
        //3.客户端发送请求，获取响应对象
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        //4.打印响应结果
        SearchHits hits = response.getHits();
        System.out.println("took::"+response.getTook());
        System.out.println("time_out::"+response.isTimedOut());
        System.out.println("total::"+hits.getTotalHits());
        System.out.println("max_score::"+hits.getMaxScore());
        System.out.println("hits::::>>");
        for (SearchHit hit : hits) {
            String sourceAsString = hit.getSourceAsString();
            System.out.println(sourceAsString);
        //打印高亮结果
            Map<String, HighlightField> highlightFields = hit.getHighlightFields();
            System.out.println(highlightFields);
        }
        System.out.println("<<::::");
    }

4.3.3 聚合函数

4.3.3.1 最大值查询

public static void MaxSelect(RestHighLevelClient client,String indexName) throws IOException {
        // 高亮查询
        SearchRequest request = new SearchRequest().indices("student");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.aggregation(AggregationBuilders.max("maxAge").field("age"));
        //设置请求体
        request.source(sourceBuilder);
        //3.客户端发送请求，获取响应对象
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        //4.打印响应结果
        SearchHits hits = response.getHits();
        System.out.println(response);
    }

4.3.3.2 分组查询

public static void GroupSelect(RestHighLevelClient client,String indexName) throws IOException {
        // 高亮查询
        SearchRequest request = new SearchRequest().indices("student");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.aggregation(AggregationBuilders.terms("age_groupby").field("age"));
        //设置请求体
                request.source(sourceBuilder);
        //3.客户端发送请求，获取响应对象
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        //4.打印响应结果
        SearchHits hits = response.getHits();
        System.out.println(response);
    }