package EasyFactoryModel;

abstract class Operation {

  public double num1=0;
  public double num2=0;
  public double getNum1() {
    return num1;
  }
  public void setNum1(double num1) {
    this.num1 = num1;
  }
  public double getNum2() {
    return num2;
  }
  public void setNum2(double num2) {
    this.num2 = num2;
  }
  
  public abstract double getResult();
}

class OpeartionAdd extends Operation {

  public double getResult(){
    double result=0;
    result=num1+num2;
    return result;
  }
}

public class OpeartionSub extends Operation {
 
  public double getResult(){
    double result=0;
    result=num1-num2;
    return result;
  }
}

public class OperationMul extends Operation {

  public double getResult(){
    double result=0;
    result=num1*num2;
    return result;
  }
}

public class OperationDiv extends Operation {
 
  public double getResult(){
    double result=0;
    result=num1/num2;
    return result;
  }
}

public class OperationFactory {
 
  public static Operation creatOpera(String operation){
     
    Operation oper=null;
    switch(operation){
     
    case "+":oper=new OpeartionAdd();break;
    case "-":oper=new OpeartionSub();break;
    case "*":oper=new OperationMul();break;
    case "/":oper=new OperationDiv();break;
     
    }
    return oper;
  }
 
}

public class Calculator {

  public static void main(String[] args) {
    
    Operation oper;
    String operation="+";
    oper=OperationFactory.creatOpera(operation);
    oper.num1=1;
    oper.num2=2;
    double result=0;
    result=oper.getResult();
    System.out.println("result="+result);
    
  }

}