Simple Factory mode Implementation subtraction method

1. Create an interface for the operation

 Public Interface operation {    // provides a method for calculating two numbers    double getresult (double num1,  Double  num2);}

2. Create a corresponding subtraction four implementation class

 public  class  addition implements  operation {//  Addition   @Override  public  double  getresult (double  num1, double   num2)    { return  num1+NUM2; }}

 public  class  minus implements  operation {//  subtraction   @Override  public  double  getresult (double  num1, double   num2)    { return  num1-NUM2; }}

 public  class  multiplication implements  operation {//  multiplication   @Override  public  double  getresult (double  num1, double   num2) { return num1*NUM2; }}

 Public class Implements Operation {// Division     @Override    publicdouble GetResult (  Doubledouble  num2) {        return num1/num2;    }}

3. Create a factory class

 Public classoperationfactory {//factory class for computers    /** Factory mode is the model of our most commonly used instanced objects!     * Replace new! with a factory method     * Although the amount of code has not decreased but increased the scalability of the program! */     Public StaticOperation Getoperation (String o) {operation Operation=NULL;// polymorphic        Switch(o) { Case"+": Operation=Newaddition ();  Break;  Case"-": Operation=Newminus ();  Break;  Case"*": Operation=Newmultiplication ();  Break;  Case"/": Operation=NewDivision ();  Break; }        returnoperation; }}

4. Create test class Run test results

 Public classFactorytest { Public Static voidMain (string[] args) {Scanner Scanner=NewScanner (system.in); System.out.println ("Please enter the first number:"); DoubleNUM1 =Scanner.nextint (); System.out.println ("Please enter operator:"); String Operation=Scanner.next (); System.out.println ("Please enter a second number:"); Doublenum2 =Scanner.nextint (); //create an instance object of an operationOperation o =Operationfactory.getoperation (operation); //Output ResultsSystem.out.println (O.getresult (NUM1, num2)); }}

Simple Factory mode Implementation subtraction method