if 就可以了.
String s1="";等他输入;
String s2="";等他输入;
if (s1=="石头"&s2=="剪刀")
syste.out.print("s2输了");if (s1=="石头"&s2=="布")
syste.out.print("s2赢了");
String s1="";等他输入;
String s2="";等他输入;
if (s1=="石头"&s2=="剪刀")
syste.out.print("s2输了");if (s1=="石头"&s2=="布")
syste.out.print("s2赢了");
system.out.print("s2赢了");