实践作业：从键盘输入一系列字符串，写入到某磁盘文件中

import java.io.*;
public class Bwriter
{
public static void main(String[] args) throws Exception
{
InputStreamReader i = new InputStreamReader(System.in);
BufferedReader b = new BufferedReader(i);
FileWriter f = new FileWriter("file.txt");
BufferedWriter w = new BufferedWriter(f);
String s;
while(true)
{
System.out.print("input a string:");
System.out.flush();
s = b.readLine();
if(s.length() == 0)
break;
w.write(s);
w.newLine();
}
w.close();
}
}