由键盘输入数据

import java.util.*;
public class Input {

    public static void main(String[] args) {
         Scanner reader=new Scanner(System.in);
         System.out.println("请输入一个正整数.");
         int i=reader.nextInt();
         System.out.println(i);
         System.out.println("请输入一段字符串.");
         String s=reader.next();
         System.out.println(s);
         }
}

import java.io.*;
public class Input {

    public static void main(String[] args) throws IOException
    {
        String str;
        BufferedReader buf=new BufferedReader(new InputStreamReader(System.in));
        System.out.println("请输入一个正整数");
        str=buf.readLine();
        int i=Integer.parseInt(str);
        System.out.println("输入的数字为"+i);
    }
}