从键盘接收一个字符串的输入 InputStreamReader

[java]代码库

import java.io.*;
public class NumberInput {
    public static void main (String args[]) {
        try {
            InputStreamReader ir;
            BufferedReader in;
            ir = new InputStreamReader (System.in);
            //ir = new InputStreamReader(System.in, "8859_1");
            //从键盘接收了一个字符串的输入，并创建了一个字符输入流的对象
            in = new BufferedReader (ir);
            String s = in.readLine();
            //从输入流in中读入一行，并将读取的值赋值给字符串变量s
            System.out.println ("Input value is: " + s);
            int i = Integer.parseInt (s); //转换成int型
            i *= 2;
            System.out.println ("Input value changed after doubled: " + i);
        } catch (IOException e) {
            System.out.println (e);
        }
    }
}