怎么用get和set方法（以JAVA为例）

当类声明了私有成员时，如果需要 获取（get） 或 设置（set） 这个私有成员的值，可以为这个私有成员编写get或set 方法 

package cn.itcast.domain;

import java.util.Date;

public class User {

 private String username;
 private String password;
 private String gender;
 private Date birthday;
 private String email;
 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 String getGender() {
  return gender;
 }
 public void setGender(String gender) {
  this.gender = gender;
 }
 public Date getBirthday() {
  return birthday;
 }
 public void setBirthday(Date birthday) {
  this.birthday = birthday;
 }
 public String getEmail() {
  return email;
 }
 public void setEmail(String email) {
  this.email = email;
 }
 
}

User u = new User();
u.setXXX();
u.getXXX();
你想给他赋值就用u.setXXX();    取这个类的对象的某个值 就get