import java.io.IOException;
import java.util.InputMismatchException;
import java.util.Scanner;

public class Test {

    /**
     * 输入限制为int数字，不是int数字重新输入
     * @throws IOException 
     */
    public static void main(String[] args) throws IOException {
        Scanner input = new Scanner(System.in);
        int num = 0;
        
        while (num == 0) {
            try {
                System.out.println("请输入一个整数：");
                num = input.nextInt();
            } catch (InputMismatchException e) {
                System.out.println("必须输入整数！请重新输入：");
                input.nextLine(); // 吃掉回车
            }
        }
        
    }
}