code: public String mgetDocuments(String index,String indexType,Object ... ids)  throws ElasticSearchException{
  		if(ids == null || ids.length ==0)
  			return null;
  		StringBuilder path = new StringBuilder();
  		if(indexType == null || indexType.equals(""))
  			path.append(index).append("/_mget");
  		else
  			path.append(index).append("/").append(indexType).append("/_mget");
  		StringBuilder builder = new StringBuilder();
  		builder.append(" {\"ids\":");
  		Writer writer = new BBossStringWriter(builder);
  		SerialUtil.object2json(ids,writer);
  		builder.append("}");
  		String searchResult = this.client.executeHttp(path.toString(),builder.toString(),   ClientUtil.HTTP_POST);
  
  		return searchResult;
  
  	}
docs: https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-multi-get.html
  @param index _mget
  test/_mget
  test/type/_mget
  test/type/_mget?stored_fields=field1,field2
  _mget?routing=key1
  @param indexType
  @param ids
  @return
  @throws ElasticSearchException