判断是否输入int类型不是重新输入
//Scanner sc = new Scanner(System.in);为什么这行方外边死循环方循环里边正常?
for (;;) {
Scanner sc = new Scanner(System.in);
if (sc.hasNextInt()) {
int i = sc.nextInt();
System.out.println(i);
break;
}else {
System.out.println("shurucuowuchongxinshuru");