singleton

package singleton;

public class Wife {
private static Wife wife;
private static String name;
private int age;

public void setAge(int age){
this.age = age;
}

private Wife(){}

public static Wife getWife(String n)
{
if(null == wife)
{

wife = new Wife();
}
name = n;
return wife;
}

public String toString()
{
if(age >= 0)
{
return "my wife's name: "+name+"  age is "+age;
}else
return "my wife's name: "+name;
}
}





package singleton;

public class Main {


public static void main(String[] args) {
Wife w = Wife.getWife("qingqing");
w.setAge(100);
System.out.println(w);
Wife wi = Wife.getWife("baibai");
System.out.println(wi);
System.out.println(w.hashCode());
System.out.println(wi.hashCode());

}

}
/**
* 单例，有什么懒汉式，饿汉式，线程安全。其实现在我的观点是。单例就是只要产生一个实例就行
* 在资源分配上就考虑下线程安全。
*/