请问2个JAVA实例·!请各位帮帮·!谢谢·! 题目1:如何保证一个类在一个应用中只能有一个实例,写代码题目2:编写一个输出"Hello World!"的程序,用两种方式实现(Application、Applet) 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 1、使用单体模式就行 public class SingleTon{private static SingleTon instance = new SingleTon();private SingleTon(){}public static SingleTon getInstance(){return instance;}}2、public class MyApplication{public static void main(String[] args){System.out.println("Hello World!");}}public class MyApplet extends Applet{public void init(){System.out.println("Hello World!");}} 一楼写的是单例模式的一种(饿汉式) , 如下是我写单例模式的另外一种(懒汉式).不过我们开发中常用的是饿汉式, 认为这种方法会比较安全!public class Singleton{ private static Singleton singleton=null; private Singleton(){} public static Singleton getInstance(){ if (singleton == null){ return new Singleton(); } }} 补充一下,上面写的有问题!public class Singleton{ private static Singleton singleton=null; private Singleton(){} public static Singleton getInstance(){ if (singleton == null){ return new Singleton(); } return singleton; } } 第一个:public class SingleInstance{ private final static SingleInstance; public SingleInstance(){ } public SingleInstance getInstance(){ if(null==SingleInstance){ return new SingleInstance(); } }} public class SingleInstance{ private final static SingleInstance; private SingleInstance(){ } public static SingleInstance getInstance(){ if(null==SingleInstance){ return new SingleInstance(); } return SingleInstance } }修改下 如何根据已知的IP来判断其ip所属地区 寻电子表格 关于String的问题 向高手求救~~~~~~~~毕业设计 在局域网中如果捕获已经发送出去的邮件 关于返回的问题.谢谢 新手问题 底层代码的“底层”应该用那个单词,在线等,十万火急。 哪里可以下载正式的jbuilder7.0(在线关注)!!! how to learn java 强制类型转换问题 请问 JAVA Enter事件 怎么写
public class SingleTon{
private static SingleTon instance = new SingleTon();private SingleTon(){}public static SingleTon getInstance(){
return instance;
}
}2、public class MyApplication{
public static void main(String[] args){
System.out.println("Hello World!");
}
}public class MyApplet extends Applet{
public void init(){
System.out.println("Hello World!");
}
}
private static Singleton singleton=null; private Singleton(){} public static Singleton getInstance(){
if (singleton == null){
return new Singleton();
}
}
}
public class Singleton{
private static Singleton singleton=null; private Singleton(){} public static Singleton getInstance(){
if (singleton == null){
return new Singleton();
}
return singleton;
}
}
public class SingleInstance{
private final static SingleInstance;
public SingleInstance(){
} public SingleInstance getInstance(){
if(null==SingleInstance){
return new SingleInstance();
}
}
}
public class SingleInstance{
private final static SingleInstance;
private SingleInstance(){
} public static SingleInstance getInstance(){
if(null==SingleInstance){
return new SingleInstance();
}
return SingleInstance
}
}
修改下