[Java知识库]一篇实现springboot集成elasticsearch的增删改查

准备工作

springboot版本

	<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.5.RELEASE</version>
    </parent>

elasticsearch版本7.6.1,是我本机安装的es版本

<!--elasticsearch-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>7.6.1</version>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-client</artifactId>
            <version>7.6.1</version>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>7.6.1</version>
        </dependency>

增

GetIndexRequest request = new GetIndexRequest("isgsg_index");
        boolean exists = client.indices().exists(request, RequestOptions.DEFAULT);//判断索引是否存在
        if (exists == false) {
            CreateIndexRequest createIndexRequest = new CreateIndexRequest("isgsg_index");//创建索引
            client.indices().create(createIndexRequest, RequestOptions.DEFAULT);
            System.out.println("********************** isgsg_index创建成功 *****************");
        }
        System.out.println("********************** isgsg_index已存在 *****************");
        User user = new User("isgsg", 21);
        IndexRequest indexRequest = new IndexRequest("isgsg_index");
        indexRequest.id("50");//设置每个文档的id，这里可以使用user的id来设置
        indexRequest.timeout(TimeValue.timeValueSeconds(2));
        indexRequest.source(JSON.toJSONString(user), XContentType.JSON);//用json格式传输实体类
        IndexResponse response = client.index(indexRequest, RequestOptions.DEFAULT);
        System.out.println("添加是否成功："  + response.status());

删

//根据文档id删除，这里的id可以是任何一个实体类的id，也可以传一个形参，但必须是string类型
        DeleteRequest deleteRequest = new DeleteRequest("isgsg_index", "1");
        deleteRequest.timeout(TimeValue.timeValueSeconds(6));
        DeleteResponse deleteResponse = client.delete(deleteRequest, RequestOptions.DEFAULT);
        System.out.println("删除是否成功：" + deleteResponse.status());

改

User user = new User("1001", "gsg",20);
        //根据userId来更改内容, 这里需要特别说明一下，这里的id如果文档中已经存在，
        // 则会覆盖原来的内容，以达到实现修改的目的，但是如果不存在此id，则es会帮我们新建一个文档
        UpdateRequest updateRequest = new UpdateRequest("isgsg_index",user.getUserId());
        updateRequest.timeout("6s");
        updateRequest.doc(JSON.toJSONString(user), XContentType.JSON);
        UpdateResponse updateResponse = client.update(updateRequest, RequestOptions.DEFAULT);
        System.out.println("更改是否成功：" + updateResponse.status());

查

• 查询所有

SearchRequest searchRequest = new SearchRequest("isgsg_index");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();//构建搜索条件
        MatchAllQueryBuilder matchAllQueryBuilder = QueryBuilders.matchAllQuery();//查询所有isgsg_index索引下的所有文档
        SearchSourceBuilder query = sourceBuilder.query(matchAllQueryBuilder);
        searchRequest.source(query);//执行搜索
        SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);//提交
        List<Map<String,Object>> user= new ArrayList<>();//储存map对象
        for (SearchHit hit : searchResponse.getHits().getHits()) {
            user.add(hit.getSourceAsMap());//封装成一个map对象，并储存到list中
        }

• 根据id查询

//查询id为3的用户
        GetRequest getRequest = new GetRequest("isgsg_index", "3");
        GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);
        Map<String, Object> map = getResponse.getSourceAsMap();//封装到map对象中

• 复合查询 （相当于 mysql 的 where 和 and 查询）这里重点说一下：复合查询的条件有：must ，filter ，mustNot ，should 等。可以根据自己的需要添加查询条件，也可以同时多个must或者其它条件。

SearchRequest searchRequest = new SearchRequest("isgsg_index");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();//构建搜索条件
        BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
        boolQueryBuilder.must(QueryBuilders.termQuery("name","黎明"))//必须是name为黎明的用户
                .must(QueryBuilders.termQuery("age",20))//且年龄必须是20岁
                .filter(QueryBuilders.termQuery("sex","male"))//过滤男性
                .mustNot(QueryBuilders.termQuery("hight","178"));//且身高必须不能是178
        sourceBuilder.query(boolQueryBuilder);
        sourceBuilder.timeout(new TimeValue(60,TimeUnit.SECONDS));
        searchRequest.source(sourceBuilder);
        SearchResponse search = client.search(searchRequest, DEFAULT);
        List<Map<String,Object>> user = new ArrayList<>();
        for (SearchHit hit : search.getHits().getHits()) {
            user.add(hit.getSourceAsMap());
        }