java如何交换这两个变量的值方法

1.借助中间量交换 
int x = 10; 
int y = 20; 
int temp = x; 
x = y; 
y = temp; 

2.数值相加减交换 
int x = 10; 
int y = 20; 
x = x + y; 
y = x - y; 
x = x - y; 

3.位移运算交换 

int x = 10; 
int y = 20; 
x = x ^ y; 
y = x ^ y; 
x = x ^ y;