fastjson如何将对象或数组转换为JSON呢？

实现思路:
    引入fastjson库
	使用JSON.parseObject方法
	即可将一个对象转换为JSON字符串

package com.java265;  
  
import java.util.Arraylist;  
import java.util.List;  
  
import com.alibaba.fastjson.JSON;  
  
class User {  
    private String name;  
    private int age;  
  
    public String getName() {  
        return name;  
    }  
  
    public void setName(String name) {  
        this.name = name;  
    }  
  
    public int getAge() {  
        return age;  
    }  
  
    public void setAge(int age) {  
        this.age = age;  
    }  
  
    @Override  
    public String toString() {  
        return "User [name=" + name + ", age=" + age + "]";  
    }  
};  
  
class UserGroup {  
    private String name;  
    private List<User> users = new ArrayList<User>();  
  
    public String getName() {  
        return name;  
    }  
  
    public void setName(String name) {  
        this.name = name;  
    }  
  
    public List<User> getUsers() {  
        return users;  
    }  
  
    public void setUsers(List<User> users) {  
        this.users = users;  
    }  
  
    @Override  
    public String toString() {  
        return "UserGroup [name=" + name + ", users=" + users + "]";  
    }  
}  
  
class FastJsonTest {  
    public static void main(String[] args) {  
        // 构建用户geust  
        User guestUser = new User();  
        guestUser.setName("maomao");  
        guestUser.setAge(18);  
        // 构建用户root  
        User rootUser = new User();  
        rootUser.setName("gougou");  
        guestUser.setAge(16);  
        // 构建用户组对象  
        UserGroup group = new UserGroup();  
        group.setName("guest");  
        group.getUsers().add(guestUser);  
        group.getUsers().add(rootUser);  
        // 用户组对象转JSON串  
        String jsonString = JSON.toJSONString(group);  
        System.out.println("jsonString:" + jsonString);  
        // JSON串转用户组对象  
        UserGroup group2 = JSON.parseObject(jsonString, UserGroup.class);  
        System.out.println("group2:" + group2);  
  
        // 构建用户对象数组  
        User[] users = new User[2];  
        users[0] = guestUser;  
        users[1] = rootUser;  
        // 用户对象数组转JSON串  
        String jsonString2 = JSON.toJSONString(users);  
        System.out.println("jsonString2:" + jsonString2);  
        // JSON串转用户对象列表  
        List<User> users2 = JSON.parseArray(jsonString2, User.class);  
        System.out.println("users2:" + users2);  
    }  
}