华波(Wiess)的博客

摘要： 1.意图提供一个创建一系列相关或相互依赖对象的接口，而无需指定它们具体的类。Code in Java:static class Expression { protected String str; public Expression(String s) { str = s; } public Expression cloan() { return null; } public String toString() { ... 阅读全文

摘要： Java code：public class Singleton { private static Singleton single = null; private Singleton() { System.out.println("create a singleton class."); } public synchronized static Singleton getInstance() { if(null == single) { single = new Singleton(); ... 阅读全文