工厂模式分析----Factory Pattern

工厂模式定义：实例化对象，用工厂方法代替new操作。
工厂模式是我们最常用的模式了，因为工厂模式就相当于创建实例对象的new，我们经常要根据类Class生成实例对象，如A a=new A() 工厂模式也是用来创建实例对象的，所以以后new时就要多个心眼，是否可以考虑使用工厂模式，虽然这样做，可能多做一些工作，但会给你系统带来更大的可扩展性和尽量少的修改量。那么具体怎么用呢？代码奉上

/**
 * 生产枪的工厂接口
 * 
 * @author Star
 * 
 */
public interface GunFactory {
	public Gun createFootGun();// 创建步枪

	public Gun createHandGun();// 创建手(***)枪

	public Gun createQuickGun();// 创建冲锋枪
}

/**
 * 生产便宜一类枪
 * 
 * @author Star
 * 
 */
public class CheapGunFactory implements GunFactory {

	public Gun createFootGun() {
		return new FootGun("小米加步枪", 50);
	}

	public Gun createHandGun() {
		return new HandGun("三八大盖", 20);
	}

	public Gun createQuickGun() {
		return new QuickGun("解放军冲锋枪", 100);
	}

}

/**
 * 贵的一类枪
 * @author Star
 *
 */
public class ExpensiveGunFactory implements GunFactory {

	public Gun createFootGun() {

		return new FootGun("德国造步枪", 150);
	}

	public Gun createHandGun() {
		return new FootGun("美国造手(***)枪", 120);

	}

	public Gun createQuickGun() {
		return new FootGun("AK47", 250);

	}

}

枪的具体类

/**
 * 枪的接口类
 * 
 * @author Star
 * 
 */
public abstract class Gun {
	protected String gunName;// 枪名
	protected int power;// 杀伤力

	// 射击
	public void shoot() {
       System.out.println(gunName+" 射击的杀伤力为： "+power);
	}

	public Gun(String gunName, int power) {
		this.gunName = gunName;
		this.power = power;
	}
}

/**
 * 步枪
 * @author Star
 *
 */
public class FootGun extends Gun{

	public FootGun(String gunName, int power) {
		super(gunName, power);
	}

	//射击
	public void shoot() {
		super.shoot();
	}

}

/**
 * 手(***)枪
 * @author Star
 *
 */
public class HandGun extends Gun {

	public HandGun(String gunName, int power) {
		super(gunName, power);
	}

	public void shoot() {
		super.shoot();
	}

}

/**
 * 冲锋枪
 * @author Star
 *
 */
public class QuickGun extends Gun {

	public QuickGun(String gunName, int power) {
		super(gunName, power);
	}

	public void shoot() {
		super.shoot();
	}
}

主函数测试类

public class FactoryMain {

	public static void main(String[] args) {
		GunFactory factory = new CheapGunFactory();
		Gun gun = factory.createHandGun();
		gun.shoot();
		gun = factory.createFootGun();
		gun.shoot();
		gun = factory.createQuickGun();
		gun.shoot();

		factory = new ExpensiveGunFactory();
		gun = factory.createHandGun();
		gun.shoot();
		gun = factory.createFootGun();
		gun.shoot();
		gun = factory.createQuickGun();
		gun.shoot();

	}

}