学步园

public class Operation<br /> {<br /> private double _numberA = 0;<br /> private double _numberB = 0;<br /> public double getnumberA()<br /> {<br /> return _numberA;<br /> }<br /> public double getnumberB()<br /> {<br /> return _numberB;<br /> }<br /> public void setnumberA(double numberA)<br /> {<br /> this._numberA = numberA;<br /> }<br /> public void setnumberB(double numberB)<br /> {<br /> this._numberB = numberB;<br /> }<br /> public double GetResult()<br /> {<br /> double result = 0;<br /> return result;<br /> }<br /> }<br /> class OperationAdd extends Operation<br /> {<br /> public double GetResult()<br /> {<br /> double result = 0;<br /> result = getnumberA() + getnumberB();<br /> return result;<br /> }<br /> }<br /> class OperationSub extends Operation<br /> {<br /> public double GetResult()<br /> {<br /> double result = 0;<br /> result = getnumberA() - getnumberB();<br /> return result;<br /> }<br /> }<br /> class OperationMul extends Operation<br /> {<br /> public double GetResult()<br /> {<br /> double result = 0;<br /> result = getnumberA() * getnumberB();<br /> return result;<br /> }<br /> }<br /> class OperationDiv extends Operation<br /> {<br /> public double GetResult()<br /> {<br /> double result = 0;<br /> if(getnumberB()==0)<br /> System.out.println("除数不能为0");<br /> else<br /> result = getnumberA() / getnumberB();<br /> return result;<br /> }<br /> }<br />
 

class OperationFactory<br /> {<br /> public static Operation createOperate(String operate)<br /> {<br /> Operation oper = null;<br /> if(operate == "+")<br /> {<br /> oper = new OperationAdd();<br /> }else if(operate == "-")<br /> {<br /> oper = new OperationSub();<br /> }else if(operate == "*")<br /> {<br /> oper = new OperationMul();<br /> }else if(operate == "/")<br /> {<br /> oper = new OperationDiv();<br /> }<br /> return oper;<br /> }<br /> }<br /> public class OperationFactoryTest1<br /> {<br /> public static void main(String[] args)<br /> {<br /> Operation oper;<br /> oper = OperationFactory.createOperate("+");<br /> oper.setnumberA(2.3);<br /> oper.setnumberB(2.4);<br /> double result = oper.GetResult();<br /> System.out.println(result);<br /> }<br /> }<br />