我们使用elasticsearch常使用它的分词查询，但是因为业务需要也需要使用多id查询，elasticsearch提供了MultiGetRequest实现多ids,多索引查询：

/*** 根据多个索引查询*/public <T> List<T> findByIds(List<String> keys, Class<T> clazz) {RestHighLevelClient client=this.restHighLevelClient();try {if(null == keys || keys.size() == 0){return  null;}// 通过MultiGetRequest.Item对象设置查询参数MultiGetRequest request = new MultiGetRequest();String[] ids = new String[keys.size()];for(int i = 0;i< keys.size();i++){ids[i] = keys.get(i);request.add( "索引名", keys.get(i));}List<T>  productList = Lists.newArrayList();MultiGetResponse response = client.mget(request, RequestOptions.DEFAULT);log.info("ES-findById:id[{}],result:{}", JSON.toJSONString(keys),response.getResponses());if(!response.isFragment()){for(MultiGetItemResponse multiGetItemResponse :response.getResponses()){GetResponse firstGet = multiGetItemResponse.getResponse();if (firstGet.isExists()) {String value =firstGet.getSourceAsString();productList.add(JSONObject.parseObject(value,clazz)) ;}}}return productList;} catch (Exception e) {throw new BizException(" findByIndexIds 搜索引擎异常:"+e.getMessage());}finally {try {client.close();} catch (IOException e) {e.printStackTrace();}}}