json
概念：javascript object notation js標示對象的一種方式
作用： 1、標示數(shù)據(jù)拜效，鍵值對形式 2草雕、保存數(shù)據(jù) 3、json可以作為數(shù)據(jù)交換的格式
特點：輕量級崇众，原生js
json對象 本質(zhì)就是js代碼 var aa={"name":"lisu"}
json數(shù)據(jù) 字符串
eval();
json數(shù)據(jù)
Map形式
- key/value
{"name":"zhangsan","age":"30"};
- object
{"stu":{"name":"lisi","age":"21"}}
- array
{"tea":[
{"name":"lisi","age":"21"},
{"name":"zhangsan","age":"22"}
]
}
- 復雜嵌套
{
"stu2":[
{"sex":0,"username":"lisi"},{"sex":0,"username":"zhaoliu"},
{"password":"123","sex":0,"username":"zhangsan"}
],
"stu1":{"password":"123","sex":1,"username":"zhangsan"}
}
- List形式
[
{"name":"lisi","age":"21"},
{"name":"zhangsan","age":"22"}
]
[
[
{"name":"lisi","age":"21"},
{"name":"zhangsan","age":"22"}
],
[
{"name":"lisi","age":"21"},
{"name":"zhangsan","age":"22"}
]
]
json工具類
訪問官網(wǎng)http://www.json.org/
找到java平臺的json工具類，例如json-java
到github下載源碼
導入到eclipse缓艳，導出jar
json-java的使用
User user=new User("zhaoliu", "123");
JSONObject json=new JSONObject(user);//將user對象轉(zhuǎn)成json對象
- list對象轉(zhuǎn)成json對象
User user1=new User("lisi","123");
User user2=new User("zhaoliu","123");
User user3=new User("zhangsan","123");
List<User> list=new ArrayList<User>();
list.add(user1);
list.add(user2);
list.add(user3);
JSONArray json=new JSONArray(list);//將list<User>轉(zhuǎn)成json對象
