FastJson

FastJson的应用

一、阿里巴巴FastJson是一个Json处理工具包，包括“序列化”和“反序列化”两部分，它具备如下特征：
速度最快，测试表明，fastjson具有极快的性能，超越任其他的Java Json parser。包括自称最快的JackJson；
功能强大，完全支持Java Bean、集合、Map、日期、Enum，支持范型，支持自省；无依赖，能够直接运行在Java SE 5.0以上版本；支持Android；开源 (Apache 2.0)

将javaBean对象包装成json格式

                JSONObject jsonObject=new JSONObject();
        User user=new User("尚晓飞", "男", 25, new Date(), "bjsxt");
        jsonObject.put("user", user);
        System.out.println("Test.main()"+jsonObject.toString());

                //打印结果：Test.main(){"user":{"age":25,"birthDay":1405067572140,"name":"尚晓飞","school":"bjsxt","sex":"男"}}

将list集合包装成json

User user=new User("尚晓飞", "男", 25, new Date(), "bjsxt");
        User user2=new User("sxf", "女", 22, new Date(), "北京尚学堂");
        User user3=new User("当当", "男", 25, new Date(), "当当网");
        List<Object> userList=new ArrayList<Object>();
        
        userList.add(user);
        userList.add(user2);
        userList.add(user3);
        
        JSONObject jsonObject=new JSONObject();
        jsonObject.put("userlist", userList);
        
        
        System.out.println("Test.main()"+jsonObject);
        
//打印结果：Test.main(){"userlist":[{"age":25,"birthDay":1405069939080,"name":"尚晓飞","school":"bjsxt","sex":"男"},{"age":22,"birthDay":1405069939080,"name":"sxf","school":"北京尚学堂","sex":"女"},{"age":25,"birthDay":1405069939080,"name":"当当","school":"当当网","sex":"男"}]}

将list集合包装成json格式的数组

User user=new User("尚晓飞", "男", 25, new Date(), "bjsxt");
        User user2=new User("sxf", "女", 22, new Date(), "北京尚学堂");
        User user3=new User("当当", "男", 25, new Date(), "当当网");
        List<Object> userList=new ArrayList<Object>();
        
        userList.add(user);
        userList.add(user2);
        userList.add(user3);
        
        JSONArray jsonArray=new JSONArray(userList);
        
        
        System.out.println("Test.main()"+jsonArray);

//打印结果:Test.main()[{"age":25,"birthDay":1405069524031,"name":"尚晓飞","school":"bjsxt","sex":"男"},{"age":22,"birthDay":1405069524031,"name":"sxf","school":"北京尚学堂","sex":"女"},{"age":25,"birthDay":1405069524031,"name":"当当","school":"当当网","sex":"男"}]

将list集合包装成json格式的数组

User user=new User("尚晓飞", "男", 25, new Date(), "bjsxt");
        User user2=new User("sxf", "女", 22, new Date(), "北京尚学堂");
        User user3=new User("当当", "男", 25, new Date(), "当当网");
        List<Object> userList=new ArrayList<Object>();
        
        userList.add(user);
        userList.add(user2);
        userList.add(user3);
        JSON json=(JSON) JSON.toJSON(userList);

  在javascript中操作json对象

//如果是一个json对象var abc={"key":"value"}
//取出key对应的值
var v=abc.key
var v=abc["key"]


//如果是一个json数组的对象   var abc=[{"one":"一","name":"尚晓飞"},{"one":"二","name":"尚小帅"}]

for(var i=0;i<abc.length;i++){
     var m=abc[i].name;
     var o=abc[i].one; 
     var m=abc[i]["name"]           
}

 FastJSON的API

public static final Object parse(String text); // 把JSON文本parse为JSONObject或者JSONArray 
public static final JSONObject parseObject(String text)； // 把JSON文本parse成JSONObject    
public static final  T parseObject(String text, Class clazz); // 把JSON文本parse为JavaBean 
public static final JSONArray parseArray(String text); // 把JSON文本parse成JSONArray 
public static final  List parseArray(String text, Class clazz); //把JSON文本parse成JavaBean集合 
public static final String toJSONString(Object object); // 将JavaBean序列化为JSON文本 
public static final String toJSONString(Object object, boolean prettyFormat); // 将JavaBean序列化为带格式的JSON文本 
public static final Object toJSON(Object javaObject); 将JavaBean转换为JSONObject或者JSONArray。

测试代码

Fave fave1=new Fave("打游戏", new Date());
        Fave fave2=new Fave("下象棋", new Date());
        
        Student st1=new Student("尚晓飞", 1,new Date(),fave1);
        Student st2=new Student("尚小帅",1,new Date(),fave2);
        
        List<Student> list=new ArrayList<Student>();
        list.add(st1);
        list.add(st2);
        
        //javaBean---》json格式字符串
        String jsonString=JSONObject.toJSONString(st1);
        String listString=JSONObject.toJSONString(list);
        System.out.println("javabean--->string"+jsonString);
        //打印结果：javabean--->string{"birthday":1411713587089,"fave":{"date":1411713587088,"name":"打游戏"},"name":"尚晓飞","sex":1}
        System.out.println("list---->String"+listString);
        //打印结果：list---->String[{"birthday":1411714397844,"fave":{"date":1411714397843,"name":"打游戏"},"name":"尚晓飞","sex":1},
        //{"birthday":1411714397844,"fave":{"date":1411714397843,"name":"下象棋"},"name":"尚小帅","sex":1}]
        
        //javaBean---》json对象
        JSONObject jsonObject=(JSONObject) JSONObject.toJSON(st1);
        
        String nameString=(String) jsonObject.get("name");//根据key值获取json对象的value值
        Object object= jsonObject.get("fave");//特殊：转成的fave内容为{key:vlaue}所以说不能够转换成fave对象，只能进行二次转换，转换成javaBean
        String fav=object.toString();
        
        //将json格式的字符串转换成---》javaBean
        Fave fave=JSONObject.parseObject(fav, Fave.class);
        System.out.println("Test.main()"+nameString);//尚晓飞
        System.out.println("Test.main()"+fave.getName());//打游戏