通过键盘执行字符的输入操作

import java.io.*;
public class SystemIn
{
	public static void main(String args[])throws Exception
	{
		InputStreamReader isr=new InputStreamReader(System.in);//in 为InputStream类型的成员变量
		BufferedReader buffer=new BufferedReader(isr);
		String str=buffer.readLine();
		while(str!=null)
		{
			System.out.print(str);
			str=buffer.readLine();
		}
		buffer.close();
	}
}