BufferedReader.readLine()讀取文件

File file = new File("C:\\Users\\Administrator\\Desktop\\test.txt");
FileReader f = new FileReader(file);
BufferedReader bf = new BufferedReader(f);

String s ;
while ((s=bf.readLine())!=null) {
    System.out.println(s);
}
不用while的判斷只會輸出一行。