fastjson null 值转换为空字符串 key值统一大小写

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fastjson 可以设置 null值 转为

SerializerFeature.WriteNullStringAsEmpty 但是这个属性只针对实体,对 map这种结构不起效

此时需要如下所示,会将全部的null值转换为空字符串

但是特别注意,null值的时候丢失了原数据类型,所以不管数字,日期,或者其他的都变成了""

所以如果有可能还是不要偷懒,尽量用实体

/* map值过滤为"",以下的配置只针对实体起效 SerializerFeature.WriteMapNullValue,SerializerFeature.WriteNullStringAsEmpty*/ public void valuefilter(){ Map<String,Object> map=new HashMap<>(); map.put("name",null); map.put("sex","男"); map.put("age",12); map.put("ECUCATION",12); map.put("people","汉"); map.put("ti",null); ValueFilter filter = new ValueFilter() { @Override public Object process(Object obj, String s, Object v) { if(v==null) return ""; return v; } }; System.out.println(JSONObject.toJSONString(map,filter ,SerializerFeature.WriteMapNullValue,SerializerFeature.WriteNullStringAsEmpty)); }

/*
    map的key值统一为小写,以下的配置只针对实体起效
    SerializerFeature.WriteMapNullValue,SerializerFeature.WriteNullStringAsEmpty*/
public void namefilter(){
    Map<String,Object> map=new HashMap<>();
    map.put("name",null);
    map.put("sex","男");
    map.put("age",12);
    map.put("ECUCATION",12);
    map.put("people","汉");
    map.put("ti",null);
    NameFilter filter = new NameFilter() {
        @Override
        public String process(Object obj, String s, Object v) {
            return s.toLowerCase();
        }
    };
    System.out.println(JSONObject.toJSONString(map,filter
            ,SerializerFeature.WriteMapNullValue,SerializerFeature.WriteNullStringAsEmpty));
}

public static void main(String[] args) {
    FastJsonTest fastJsonTest=new FastJsonTest();
    //fastJsonTest.valuefilter();
    fastJsonTest.namefilter();
}