fastjson序列化定制過濾器

fastjson在序列化時支持傳入自定義的序列號過濾器，來定制序列化的結果

fastjson支持6種SerializeFilter，用於不同場景的定制序列化。

PropertyPreFilter 根據PropertyName判斷是否序列化
PropertyFilter 根據PropertyName和PropertyValue來判斷是否序列化
NameFilter 修改Key，如果需要修改Key,process返回值則可
ValueFilter 修改Value
BeforeFilter 序列化時在最前添加內容
AfterFilter 序列化時在最后添加內容

舉個例子

public class Test  {
    public static void main(String[] args) {

        HashMap<String, Object> map = new HashMap<>();
        map.put("bizmonth","2020-12");
        map.put("cust_total_num","0");
        map.put("ventilation_total_num_1m","11");
        HashMap<String, Object> map1 = new HashMap<>();
        map1.put("bizmonth","2020-12");
        map1.put("cust_total_num","0");
        map1.put("ventilation_total_num_1m","11");
        ArrayList<HashMap<String, Object>> mapList = Lists.newArrayList(map1, map);
        System.out.println(map);
        System.out.println("---------------");
        String s = JSON.toJSONString(mapList, new ValueFilter() {
            @Override
            public Object process(Object o, String name, Object value) {
                if (name.equals("bizmonth")) {
                    return "*****";
                }
                return value;
            }
        });
        
        System.out.println(s);
    }
}

輸出

[{"bizmonth":"*****","ventilation_total_num_1m":"11","cust_total_num":"0"},{"bizmonth":"*****","ventilation_total_num_1m":"11","cust_total_num":"0"}]

 應用：對json中的日期進行格式化轉換

public class DateTransform {
    public static String transform(String srcData, String srcFormat, String dstFormat) {
        DateFormatEnum from = DateFormatEnum.valueOf(srcFormat);
        DateFormatEnum to = DateFormatEnum.valueOf(dstFormat);
        TemporalAccessor parse = from.parse(srcData);
        return to.format(parse);
    }

    public static void main(String[] args) {

        HashMap<String, Object> map = new HashMap<>();
        map.put("bizmonth", "2020-12");
        map.put("cust_total_num", "0");
        map.put("ventilation_total_num_1m", "11");
        HashMap<String, Object> map1 = new HashMap<>();
        map1.put("bizmonth", "2020-12");
        map1.put("cust_total_num", "0");
        map1.put("ventilation_total_num_1m", "11");
        ArrayList<HashMap<String, Object>> mapList = Lists.newArrayList(map1, map);
        System.out.println(map);
        System.out.println("---------------");
        String s = JSON.toJSONString(mapList, new ValueFilter() {
            @Override
            public Object process(Object o, String name, Object value) {
                if (name.equals("bizmonth")) {
                    return transform((String) value, "YM", "YM2");
                }
                return value;
            }
        });

        System.out.println(s);
    }
}