使用fastjson转化数据时处理Map中value为null时不返回的问题

心已赠人 2022-12-19 11:54 98阅读 0赞

先上代码  一种是返回null   一种是将返回的null改为空字符串

>     package com.chingchou.jz;
>     
>     import com.alibaba.fastjson.JSON;
>     import com.alibaba.fastjson.JSONObject;
>     import com.alibaba.fastjson.serializer.SerializerFeature;
>     import com.alibaba.fastjson.serializer.ValueFilter;
>     
>     import java.util.List;
>     import java.util.Map;
>     
>     public class T {
>         public static void main(String[] args) {
>             String test = "{\"DataType\":\"json\",\"ExceptionMessage\":\"\",\"ErrorServiceId\":null,\"DataList\":[{\"zjlx\":null,\"bdcdwh\":\"340104482009GB00046F00040006\"}]}";
>             JSONObject data1 = JSONObject.parseObject(test);
>             System.out.println("data1===>"+data1);
>     
>             String string = JSON.toJSONString(data1.get("DataList"), SerializerFeature.WriteMapNullValue);
>             List<Map> data2 = JSONObject.parseArray(string, Map.class);
>             System.out.println("data2===>"+data2.get(0));
>     
>             String data3 = JSON.toJSONString(data2.get(0), filter);
>             System.out.println("data3===>"+data3);
>     
>         }
>     
>         private static ValueFilter filter = new ValueFilter() {
>             @Override
>             public Object process(Object obj, String s, Object v) {
>                 if(v==null)
>                     return "";
>                 return v;
>             }
>         };
>     
>     }

输出结果

> data1===>\{"DataList":\[\{"bdcdwh":"340104482009GB00046F00040006"\}\],"ExceptionMessage":"","DataType":"json"\}  
> data2===>\{zjlx=null, bdcdwh=340104482009GB00046F00040006\}  
> data3===>\{"zjlx":"","bdcdwh":"340104482009GB00046F00040006"\}