1、指定序列化顺序
缺省fastjson序列化一个java bean，是根据fieldName的字母序进行序列化的，你可以通过ordinal指定字段的顺序。这个特性需要1.1.42以上版本。
1 public static class VO { 2 ????@JSONField(ordinal = 3) 3 ????private int f0; 4 ?5 ????@JSONField(ordinal = 2) 6 ????private int f1; 7 ?8 ????@JSONField(ordinal = 1) 9 ????private int f2;10 }2、fastjson 忽略字段：
1 public void test01(){ 2 ????????List<User> list = new ArrayList<>(); 3 ?4 ????????User user1 = new User("lisi", 14); 5 ????????User user2 = new User("zs", 18); 6 ?7 ????????list.add(user1); 8 ????????list.add(user2); 9 10 ????????System.out.println("未忽略字段前:"+JSONArray.toJSON(list));//未忽略前:[{"name":"lisi","age":14},{"name":"zs","age":18}]11 12 ????????SimplePropertyPreFilter filter = new SimplePropertyPreFilter();13 ????????filter.getExcludes().add("age");14 ????????System.out.println("忽略字段后:"+JSONObject.toJSONString(list, filter));//忽略后:[{"name":"lisi"},{"name":"zs"}]15 ????}3、fastjson 格式化日期：
1 ?public void test01() {2 3 ????????User lisi = new User("lisi", 13, new Date());4 ????????System.out.println(lisi);//User{name=‘lisi‘, age=13, date=Fri Mar 30 22:00:48 CST 2018}5 ????????System.out.println(JSON.toJSONStringWithDateFormat(lisi, "yyyy-MM-dd HH:mm:ss.SSS"));6 ????????//{"age":13,"date":"2018-03-30 21:59:33.204","name":"lisi"}7 8 ????}4、抽取忽略字段形成工具：
1 ????/** 2 ?????* @param list 3 ?????* @param args 排除字段 4 ?????* @return 5 ?????*/ 6 ????public static String list2Json(List list,String[] args){ 7 ????????if (args != null && args.length>0){ 8 ????????????SimplePropertyPreFilter filter = new SimplePropertyPreFilter(); 9 ????????????for (String arg : args) {10 ????????????????filter.getExcludes().add(arg);11 ????????????}12 ????????????return JSONObject.toJSONString(list, filter);13 ????????}14 ????????return JSONObject.toJSONString(list);15 ????}FastJson的忽略字段和格式日期用法
原文地址：https://www.cnblogs.com/gdwkong/p/8679207.html