简单工厂模式的UML图

 

源码：Operation类

 

package Operation;

public abstract class Operation {
    double numberA=0;
    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 abstract double operate();
}

 加类：

 

package Operation;

public class Add extends Operation {

    @Override
    public double operate() {
        return numberA+numberB;
    }
}

 减类：

 

package Operation;

public class Sub extends Operation {

    @Override
    public double operate() {
        return numberA-numberB;
    }
}

 乘类：

 

package Operation;

public class Mul extends Operation {

    @Override
    public double operate() {
        return numberA*numberB;
    }
}

 除类：

 

package Operation;

import java.io.IOError;

public class Div extends Operation {

    @Override
    public double operate() {
        try {
            return numberA/numberB;
        } catch (IOError e) {
            System.out.println("除数不能为空！");
            return 0;
        }
    }
}

 

工厂类:

 

import Operation.Add;
import Operation.Div;
import Operation.Mul;
import Operation.Operation;
import Operation.Sub;

public class OperationFactory {
    public static Operation createOperation(char operate){
        Operation operation=null;
        switch (operate) {
        case '+':
            operation=new Add();
            break;
        case '-':
            operation=new Sub();
            break;
        case '*':
            operation=new Mul();
            break;
        case '/':
            operation=new Div();
            break;
        }
        return operation;
    }
}

 客户端：

 

import Operation.Operation;
public class Client {

    public static void main(String[] args) {
        Operation operation = OperationFactory.createOperation('*');
        operation.setNumberA(12);
        operation.setNumberB(6);
        System.out.println(operation.operate());
    }
}

-------------------转自http://hlzhou.iteye.com/blog/551492-------------------------------------------------