import java.lang.reflect.Field;

/**
 * @description: 利用反射在方法中交换两个 Integer 的值
 * @author: 枫子翰
 * @date: 2017/12/5 19:52
 * @version: V1.0
 */
public class TestChange {

    public static void main(String[] args)throws Exception {
        Integer x = 100;
        Integer y = 8;
        System.out.println("交换前：x="+x+";y="+y);
        changeRight(x,y);
        //changeWrong1(x,y);
        //changeWrong2(x,y);
        System.out.println("交换后：x="+x+";y="+y);
        Integer p = 100;
        System.out.println("Integer p = 100;  p="+p);
    }


    public static void changeRight(Integer i1,Integer i2) throws Exception {
        Field fun=Integer.class.getDeclaredField("value");
        fun.setAccessible(true);
        Integer swap=new Integer(i1.intValue());
        fun.set(i1,i2);
        fun.set(i2,swap);
    }

    public static void changeWrong1(Integer i1,Integer i2) throws Exception{
        Field fun = Integer.class.getDeclaredField("value");
        fun.setAccessible(true);
        Integer swap = i1;
        fun.set(i1,i2);
        fun.set(i2,swap);
    }

    private static void changeWrong2(Integer x, Integer y) throws Exception{
        Field fun = Integer.class.getDeclaredField("value");
        fun.setAccessible(true);
        int swap = x;
        fun.set(x,y);
        fun.set(y,swap);
    }

}