单例模式饿汉式

1.User类;

public class User {
//给定一个对象最终的;
public static final User user=new User();
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public static User getUser() {
return user;
}

}

2.TestUser类；

public class TestUser {
public static void main(String[] args) {
User u1=User.getUser();
User u2=User.getUser();
u1.setName("tom");
u2.setName("link");
System.out.println(u1.getName());
System.out.println(u2.getName());
}
}

3.程序运行如下:

link
link