java新手的问题,看到很多类似的，下面麻烦高手详细解释一下我下面的程序

Question

package cn.csdn.domain;

import java.io.Serializable;

public class User implements Serializable{
private int id;
private String username;
private String password;
private int age;
private String sex;
public User() {
super();
// TODO Auto-generated constructor stub
}
public User(String username, String password, int age, String sex) {
super();
this.username = username;
this.password = password;
this.age = age;
this.sex = sex;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
@Override
public String toString() {
return "User [id=" + id + ", username=" + username + ", password="
+ password + ", age=" + age + ", sex=" + sex + "]";
}

}
请问上面的这些程序是什么意思，有什么作用

Answer 1

定义了一个User对象并实现序列化接口。
public class User implements Serializable

自定义构造函数。
public User(String username, String password, int age, String sex) {
super();
this.username = username;
this.password = password;
this.age = age;
this.sex = sex;
}

内含以下成员变量。
private int id;
private String username;
private String password;
private int age;
private String sex;

并实现get和set方法。
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
......
该对象重写了Object类的toString()方法。
@Override
public String toString() {
return "User [id=" + id + ", username=" + username + ", password="

• password + ", age=" + age + ", sex=" + sex + "]"; } }