java使用fastjson进行数据的封装

fastjson是阿里巴巴推出的json工具。号称是最快的。阿里的产品还是比较靠谱的，fastjson使用起来也是非常的容易。首先导入一个fastjsonjar包可以去官网下载，也可以使用maven直接引入

测试代码如下：
建一个bean类

public class User {    private String userId;    private String name;    private int age;    public User(String userId, String name, int age) {        this.userId = userId;        this.name = name;        this.age = age;    }    public User() {    }    public String getUserId() {        return userId;    }    public void setUserId(String userId) {        this.userId = userId;    }    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{" +                "userId='" + userId + '\'' +                ", name='" + name + '\'' +                ", age=" + age +                '}';    }}

使用fastjson进行转化

        User user = new User("0001","zhangsan",120);        User user2 = new User("0002","lisi",100);        List<User>users = new ArrayList<>();        users.add(user);        users.add(user2);        String jsonUsers = JSON.toJSONString(users);        System.out.println(jsonUsers);        List<User>users2 = JSON.parseArray(jsonUsers,User.class);        for(User u : users2){            System.out.println(u);        }        System.out.println(JSON.toJSONString(user));        Map<String,Object> map = new HashMap<>();        map.put("code",0);        map.put("msg","访问成功");        map.put("result",users);        PrintWriter out = response.getWriter();        String res = JSON.toJSONString(map);        out.write(res);        out.flush();        out.close();    }

输出结果和页面打印的结果分别为：

[{"age":120,"name":"zhangsan","userId":"0001"},{"age":100,"name":"lisi","userId":"0002"}]User{userId='0001', name='zhangsan', age=120}User{userId='0002', name='lisi', age=100}{"age":120,"name":"zhangsan","userId":"0001"}

{"msg":"访问成功","result":[{"age":120,"name":"zhangsan","userId":"0001"},{"age":100,"name":"lisi","userId":"0002"}],"code":0}