RestHighLevelClient复杂查询 resthighlevelclient操作集合

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bigrobin 2024-06-16 10:07:04

文章标签 elasticsearch java 大数据客户端 json 文章分类 云原生云计算

Java调用ES客户端 [支持ES6.x]

Java高级别REST客户端（The Java High Level REST Client）以后简称高级客户端，内部仍然是基于低级客户端。它提供了更多的API，接受请求对象作为参数并返回响应对象，由客户端自己处理编码和解码。

每个API都可以同步或异步调用。同步方法返回一个响应对象，而异步方法的名称以async后缀结尾，需要一个监听器参数，一旦收到响应或错误，就会被通知（由低级客户端管理的线程池）。

高级客户端依赖于Elasticsearch core项目。它接受与TransportClient相同的请求参数并返回相同的响应对象。

下面是代码：

Pom依赖：使用的是6.4.3版本

<dependency>
      <groupId>org.elasticsearch.client</groupId>
      <artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>6.4.3</version>
</dependency>

Java 工具类(最简单的获取客户端方式，其他花哨的东西就不写了)

/**
获取客户端
**/
 public static RestHighLevelClient getClient() {
    return new RestHighLevelClient(
        RestClient.builder(new HttpHost("localhost", 9200, "http")));
  }

下面的client都为上面的getClient()

1elasticsearchCRUD操作

/**
     * 根据QueryBuilder来查询全部的条数
     *
     * @param indexName 索引
     * @param typeName  类型
     * @param id   id
     * @return 条数
     * @throws IOException 异常
     */
    public SearchResponse idQuery(String[] indexName, String typeName, String id) throws IOException {
        SearchRequest searchRequest = new SearchRequest(filterIndexName(indexName));
        searchRequest.types(typeName);
        searchRequest.source().query(QueryBuilders.idsQuery().addIds(id));
        return client.search(searchRequest);
    }

    /**
     * 根据QueryBuilder来查询全部的条数
     *
     * @param indexNameArray 索引
     * @param typeName  类型
     * @param builder   查询构建器
     * @return 条数
     * @throws IOException 异常
     */
    public Long getTotalRecords(String[] indexNameArray, String typeName, QueryBuilder builder) throws IOException {
        String[] indexArr = filterIndexName(indexNameArray);
        if(indexArr.length == 0)
            return 0L;
        SearchRequest searchRequest = new SearchRequest(indexArr);
        searchRequest.types(typeName);
        searchRequest.source().query(builder);
        SearchResponse response = client.search(searchRequest);
        return response.getHits().getTotalHits();
    }

    /**
     * 查询全部
     *
     * @param indexName 索引
     * @param typeName  类型
     * @param builder   查询构建器
     * @return SearchResponse
     * @throws IOException 异常
     */
    public SearchResponse findAll(String indexName, String typeName, QueryBuilder builder) throws IOException {
        SearchRequest request = new SearchRequest(indexName);
        request.types(typeName);
        request.source().query(builder);
        return client.search(request);
    }


    /**
     * 分页
     *
     * @param indexNameArray    索引
     * @param typeName     类型
     * @param queryBuilder 参数
     * @param from         从第几条
     * @param size         页面条数
     * @param sortBuilder  排序
     * @return response
     * @throws IOException 异常
     */
    public SearchResponse page(String[] indexNameArray, String typeName, QueryBuilder queryBuilder, int from, int size, SortBuilder sortBuilder)
            throws IOException {
        String[] indexArr = filterIndexName(indexNameArray);
        if(indexArr.length == 0){
            logger.error("选择的时间区间中没有数据");
            return null;
        }
        SearchRequest request = new SearchRequest(indexArr).types(typeName);
        //构建搜寻器
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        //参数
        sourceBuilder.query(queryBuilder);
        //排序
        sourceBuilder.sort(sortBuilder);
        //分页
        sourceBuilder.from(from);
        sourceBuilder.size(size);

        request.source(sourceBuilder);
        return client.search(request);
    }


    /**
     * 批量插入数据
     *
     * @param indexName 索引
     * @param typeName  类型
     * @param valueMap  map
     * @return BulkResponse
     * @throws IOException 异常
     */
    public BulkResponse insert(String indexName, String typeName, Map<String, String> valueMap) throws IOException {
        BulkRequest bulkRequest = new BulkRequest();
        Set<String> keySet = valueMap.keySet();
        for (String id : keySet) {
            IndexRequest request = new IndexRequest(indexName);
            request.type(typeName);
            request.index(indexName).id(id).source(valueMap.get(id), XContentType.JSON);
            bulkRequest.add(request);
        }
        return client.bulk(bulkRequest);
    }

    /**
     * 更新- 根据id进行更新(插入时根据id进行覆盖)
     */
    public void update(String indexName, String typeName,String id,String jsonStr)throws IOException{
        insert(indexName,typeName,id,jsonStr);
    }

    /**
     * 批量更新
     */
    public void update(String indexName, String typeName, Map<String, String> valueMap)throws IOException{
        insert(indexName,typeName,valueMap);
    }

    /**
     * 根据id进行删除
     *
     * @param indexName 索引
     * @param typeName  类型
     * @param id        id
     * @throws IOException 异常
     */
    public void delete(String indexName, String typeName, String id) throws IOException {
        DeleteRequest deleteRequest = new DeleteRequest(indexName, typeName, id);
        client.delete(deleteRequest);
    }

    public SearchResponse selectAll(String[] indexName, String typeName) throws IOException {
        SearchRequest searchRequest = new SearchRequest(filterIndexName(indexName));
        searchRequest.types(typeName);
        searchRequest.source().query(QueryBuilders.boolQuery());
        return client.search(searchRequest);
    }

    /**
     * Es文档数据插入(插入前会自动生成index)
     *
     * @param indexName 索引名称
     * @param typeName  类型名称
     * @param id        id
     * @param jsonStr   json数据
     * @return IndexResponse
     * @throws IOException 异常
     */
    public IndexResponse insert(String indexName, String typeName, String id, String jsonStr) throws IOException {
        IndexRequest indexRequest = new IndexRequest(indexName, typeName, id);
        indexRequest.source(jsonStr, XContentType.JSON);
        return client.index(indexRequest);
    }

    /**
     * 过滤不存在的indexName
     *
     * @param indexNameArray 索引数组
     * @return 索引数组
     * @throws IOException 异常
     */
    private String[] filterIndexName(String[] indexNameArray) throws IOException {
        List<String> resultList = new ArrayList<>();
        for (String indexName : indexNameArray) {
            GetIndexRequest request = new GetIndexRequest().indices(indexName);
            boolean exists = client.indices().exists(request);
            if (exists) resultList.add(indexName);
        }
        int size = resultList.size();
        return resultList.toArray(new String[size]);
    }

2对取到的Es返回值做解析

//这边涉及到业务代码，就不放全了了，简单放几个解析的方法
SearchResponse response = getClient().page(...);
      if (null != response) {
      	//取到hits
        SearchHit[] hits = response.getHits().getHits();
        if (null != hits) {
          for (SearchHit hit : hits) {
            //这就是取到的数据的Json格式数据
            String source = hit.getSourceAsString();
            //使用Gson转换成Bean放进结果list中
            T obj = GsonUtils.read(source, clazz);
            resultList.add(obj);
          }
        }
      }


所以:
//就是获取所取到列表的全部数据
SearchHit[] hits = response.getHits().getHits(); 
//然后每一个hit的sourse字符串当然就是取到对象的Json字符串了
String source = hit.getSourceAsString();

RestHighLevelClient复杂查询 resthighlevelclient操作集合_json