简单工厂模式

面向对象的程序设计就是通过封装、继承、多态把程序的耦合度降低。用设计模式是的程序设计更加灵活，容易修改，并且易于复用。

下面就以一个加减乘除的例子在展现简单工厂模式的应用。

操作类 operation：

package com.kunl.simplefactory;

public abstract class Operation {
	private double numberA = 0;
	private double numberB = 0;

	public double getNumberA() {
		return numberA;
	}

	public void setNumberA(double numberA) {
		this.numberA = numberA;
	}

	public double getNumberB() {
		return numberB;
	}

	public void setNumberB(double numberB) {
		this.numberB = numberB;
	}

	public double getResult() {
		double result = 0;
		return result;
	}
}

 

增加实例类OperationAdd：

package com.kunl.simplefactory;

public class OperationAdd extends Operation {
	@Override
	public double getResult() {
		double result = 0;
		result = getNumberA()+getNumberB();
		return result;
	}
}

 相减实例类OperationSub：

package com.kunl.simplefactory;

public class OperationSub extends Operation {
	@Override
	public double getResult() {
		double result = 0;
		result = getNumberA()-getNumberB();
		return result;
	}
}

 

相乘实例类OperationMul：

package com.kunl.simplefactory;

public class OperationMul extends Operation {
	@Override
	public double getResult() {
		double result = 0;
		result = getNumberA()*getNumberB();
		return result;
	}
}

 

相除实例类OperationDiv：

package com.kunl.simplefactory;

public class OperationDiv extends Operation {
	@Override
	public double getResult() {
		double result = 0;
		if(getNumberB()==0){
			System.out.println("除数不能为0");
			return result;
		}
		result = getNumberA()/getNumberB();
		return result;
	}
}

 

工厂类实现业务封装OperationFactory：

package com.kunl.simplefactory;

public class OperationFactory {
	public static Operation createOperate(char operate){
		Operation oper = null;
		switch(operate){
		case '+':
			oper = new OperationAdd();
			break;
		case '-':
			oper = new OperationSub();
			break;
		case '*':
			oper = new OperationMul();
			break;
		case '/':
			oper = new OperationDiv();
			break;
		}
		return oper;
	}
}

 客户端代码实现Client：

package com.kunl.simplefactory;


public class Client {
	public static void main(String[] args) {
		Operation oper = OperationFactory.createOperate('+');
		oper.setNumberA(1);
		oper.setNumberB(2);
		System.out.println(oper.getResult());
	}
}

全部代码在附件里面