在 elasticSearch 中使用 RestClient 检索特定字段

Question

我在弹性搜索中存储了以下文档

{"Book_Id" : "102" ,"Book_Name" : "Alice in wonderLand", "Review_Text" :"DescentRead","Rating_Percentage" :"100" }'
{"Book_Id" : "102" ,"Book_Name" : "Alice in wonderLand", "Review_Text" :"For Kids","Rating_Percentage" :"50" }'
{"Book_Id" : "103" ,"Book_Name" : "Blah Blah", "Review_Text" :"Great","Rating_Percentage" :"100" }'

我想进行搜索并仅检索一个字段（在本例中为查看文本）作为输出。我正在使用以下代码

SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();  
searchSourceBuilder.query(QueryBuilders.matchQuery("Book_Id", "102"))
        .fields("_source.Review_Text");
Search search = new Search.Builder(searchSourceBuilder.toString())
                .addIndex("reviews")
                .addType("bookreview")
                .build();

SearchResult 结果 = client.execute(search);

但我不断收到错误 -

{"error":{"root_cause":[{"type":"parsing_exception","reason":"Deprecated field [fields] used, expected [stored_fields] instead","line":10,"col":14}],

这里缺少什么？我们如何只检索特定的文件而不是所有字段作为 Json

谢谢 沙布纳

Answer 1

不推荐直接访问fields，如错误消息中所述。请改用source filtering：

SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();  
searchSourceBuilder.query(QueryBuilders.matchQuery("Book_Id", "102"))
        .fetchSource("Review_Text", null);                    <-- change this line
Search search = new Search.Builder(searchSourceBuilder.toString())
                .addIndex("reviews")
                .addType("bookreview")
                .build();