[java design pattern] interpreter pattern

Step 1: Create an interpreter interface (in which an auxiliary parameter is passed in, so we first create an auxiliary class Context, which is optional)

public class Context {
    private int num1;;
    private int num2;
	public int getNum1() {
		return num1;
	}
	public void setNum1(int num1) {
		this.num1 = num1;
	}
	public int getNum2() {
		return num2;
	}
	public void setNum2(int num2) {
		this.num2 = num2;
	}
	public Context(int num1, int num2) {
		super();
		this.num1 = num1;
		this.num2 = num2;
	}
}

public interface Expression {
     public int interpret(Context context);
	}

Step 2: Create the concrete implementation class of the interpreter

public class Minus implements Expression{

	public int interpret(Context context) {
		return context.getNum1()-context.getNum2();
	}

}

Step 3: Test

public class Test {
    public static void main(String[] args) {
		int result= new Minus().interpret(new Context(5, 5));
		System.out.println("5-5="+result);
	}
}