sunlling的专栏

<br />一个对象只想要存在一个实例。<br /> <br />实现方法：<br /> <br />方法一：<br />public class Singleton{<br /> <br />    private static Singleton instance;   // 1<br /> <br />    private Single(){}  //2<br /> <br />    public synchronized static Singleton getInstance(){ // 3<

如果猫一叫，老鼠就跑，你会用什么模式。这里可以用观察者模式。 public interface ICat {  public void addObserver(IMouse m);    public void removeObserver(IMouse m);    public void notifyObserver();    //primary method (main b

/*  * Created on 2011-4-21  *  * TODO To change the template for this generated file go to  * Window - Preferences - Java - Code Style - Code Templates  */ package com.pg.commerce.utils; import

private void compressTOGZfile(String file,String time)throws Exception{      FileInputStream fis = new FileInputStream(new File(file+"_"+time+".xml"));    FileOutputStream fos = new FileOutputStr

import java.util.ArrayList; import java.util.Iterator; import java.util.List; import java.util.Map; import org.apache.commons.httpclient.HttpClient; import org.apache.commons.httpclient.NameValue

public class LoggerHelp {      public static Logger getInstance(String name){      String path =log4jpath;   PropertyConfigurator.configure(path);   return Logger.getLogger(name);  } }   l

package com.pg.commerce.utils; import java.io.File; import java.io.IOException; import javax.xml.transform.Source; import javax.xml.transform.stream.StreamSource; import javax.xml.validation.Sche