list转json时保存值为空的属性

   String  param=JSONObject.toJSONString(fhlist, SerializerFeature.WriteMapNullValue);

效果

[{"channel_id":1,"channel_name":"测试通道","channel_Url":null}]

 

maven的代码

<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.35</version>
        </dependency>