java中将数组、对象、Map、List转换成JSON数据

1、将数组转换为JSON： String[] arr = {"asd","dfgd","asd","234"};JSONArray jsonarray = JSONArray.fromObject(arr);System.out.println(jsonarray);

2、对象转换成JSON：UserInfo user = new UserInfo(1001,"张三");JSONArray jsonArray = JSONArray.fromObject(user); System.out.println( jsonArray );

3、把Map转换成json， 要使用jsonObject对象： Map<String, Object> map = new HashMap<String, Object>(); map.put("userId", 1001); map.put("userName", "张三"); map.put("userSex", "男"); JSONObject jsonObject = JSONObject.fromObject(map); System.out.println(jsonObject);

4、把List转换成JSON数据： List<UserInfo> list = new ArrayList<UserInfo>(); UserInfo user = new UserInfo(1001, "张三"); list.add(user); list.add(user); list.add(user); JSONArray jsonArray = JSONArray.fromObject(list); System.out.println(jsonArray);