public class GetWrite {
    public static void main(String args[]) throws Exception {
        OutputStream os = null;
        InputStream is = null;
        try {
            os = new BufferedOutputStream(new FileOutputStream("a.txt"));
            is = new BufferedInputStream(System.in);
            int i;
            while((i = is.read()) != -1) {
                if(i == (int)'\n') { // 设置退出条件，这里为回车符
                    break;
                }
                os.write(i);
            }
        } catch (Exception e) {
            System.out.println(e);
        } finally {
            is.close();
            os.close();
        }
    }
}