大话设计模式java版本 第一章 简单工程模式

public abstract class Operation {
private double _numberA;
private double _numberB;

public Operation() {
super();
}

public Operation(double _numberA, double _numberB) {
super();
this._numberA = _numberA;
this._numberB = _numberB;
}

public double get_numberA() {
return _numberA;
}

public void set_numberA(double _numberA) {
this._numberA = _numberA;
}

public double get_numberB() {
return _numberB;
}

public void set_numberB(double _numberB) {
this._numberB = _numberB;
}

public abstract double getResult();
}

public class OperationAdd extends Operation {

@Override
public double getResult() {
double result = 0;
result=super.get_numberA()+super.get_numberB();
return result;
}

}

public class OperationSub extends Operation{

@Override
public double getResult() {
double result=0;
result=super.get_numberA()-super.get_numberB();
return result;
}

}

public class OperationFactory {
public static Operation creatOperation(String operate){
Operation opera=null;
switch(operate){
case "+":
opera=new OperationAdd();
break;

case "-":
opera=new OperationSub();
break;

}
return opera;
}
}

public class test {
public static void main(String[] args) {
Operation opera;
opera=OperationFactory.creatOperation("+");
opera.set_numberA(5);
opera.set_numberB(6);
System.out.println(opera.getResult());
}
}