java中两个数交换

public class Exchange {
    public static void main(String[] args) {
        int num1=8;
        int num2=9;
        System.out.println("交换前：");
        System.out.println("num1:"+num1);
        System.out.println("num2:"+num2);
        //两个数交换
        int num3=num1;
        num1=num2;
        num2=num3;

        System.out.println("交换后：");
        System.out.println("num1:"+num1);
        System.out.println("num2:"+num2);

    }
}