單例模式根據實例化對象時機的不同分為兩種：一種是餓漢式單例，一種是懶漢式單例。
私有的構造方法
指向自己實例的私有靜態引用
以自己實例為返回值的靜態的公有的方法
餓漢式單例
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public class Singleton { private static Singleton singleton = new Singleton(); private Singleton(){} public static Singleton getInstance(){ return singleton; }} |
懶漢式單例
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public class Singleton { private static Singleton singleton; private Singleton(){} public static synchronized Singleton getInstance(){ if(singleton==null){ singleton = new Singleton(); } return singleton; }}<br> |
工廠方法模式代碼
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interface IProduct { public void productMethod(); } class Product implements IProduct { public void productMethod() { System.out.println("產品"); } } interface IFactory { public IProduct createProduct(); } class Factory implements IFactory { public IProduct createProduct() { return new Product(); } } public class Client { public static void main(String[] args) { IFactory factory = new Factory(); IProduct prodect = factory.createProduct(); prodect.productMethod(); } } |
抽象工廠模式代碼
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interface IProduct1 { public void show();}interface IProduct2 { public void show();}class Product1 implements IProduct1 { public void show() { System.out.println("這是1型產品"); }}class Product2 implements IProduct2 { public void show() { System.out.println("這是2型產品"); }}interface IFactory { public IProduct1 createProduct1(); public IProduct2 createProduct2();}class Factory implements IFactory{ public IProduct1 createProduct1() { return new Product1(); } public IProduct2 createProduct2() { return new Product2(); }}public class Client { public static void main(String[] args){ IFactory factory = new Factory(); factory.createProduct1().show(); factory.createProduct2().show(); }} |
希望本文對各位朋友有所幫助
原文鏈接：http://blog.csdn.net/wuxiao5570/article/details/70154159
