第一天 工厂模式之简单工厂模式

首先定义一个接口

public interface Car {
	public void drive();
}

两个实现类

public class BMWCar implements Car{
	public void drive() {
		System.out.println("驾驶了一辆宝马汽车");
	}
}

public class QQCar implements Car{
	public void drive() {
		System.out.println("驾驶了一辆QQ汽车");
	}
}

一个静态工厂，因为是静态的方法，所以又简单工厂模式又称为静态工厂模式。

public class CarFactory {
	public static Car factory(String witch) throws BadCarException {
		if(witch.equalsIgnoreCase("QQCar")) {
			return new QQCar();	
		} else if(witch.equalsIgnoreCase("BMWCar")) {
			return new BMWCar();	
		} else {
			throw new BadCarException(witch);
		}
	}
}

public class BadCarException extends Exception {
	public BadCarException(String msg) {
		super(msg);
	}
}

测试类

public class Client {
	public static void main(String[] args) {
		try {
			Car bmwCar = CarFactory.factory("BMWCar");
			Car qqCar = CarFactory.factory("QQCar");
			bmwCar.drive();
			qqCar.drive();
		} catch (BadCarException e) {
			e.printStackTrace();
		}
	}
}