为什么我的文件写入器在写入文件时会留下不必要的行？

Question

我有filewriter（显然）用于将用户信息写入文件;写得很好，程序运行正常，但是作者没有以所需的方式写入文件。我曾经注意到它写入的文件，它会留下空白行，有时我不想要它，我不明白为什么。下面是与文件编写相关的代码（它是文件中唯一使用filewriter的位置）。所有变量等都已定义并正常工作。

    Details = "Name: " + name + " CardNo: " + CardNo + " Current Balance: " + balance + " overdraft? " + OverDraft + " OverDraftLimit: " + OverDraftLimit + " pin: " + PinToWrite;
    try{
        //Create writer to write to files.
        File file = new File(DirToWriteFile);
        FileOutputStream fos = new FileOutputStream(file, true); // **note second param?**
        Writer bw = new BufferedWriter(new OutputStreamWriter(fos, "UTF8"));        
        // FileReader reads text files in the default encoding.
        FileReader fileReader = new FileReader("VirtualATM.txt");
        // Always wrap FileReader in BufferedReader.
        BufferedReader bufferedReader = new BufferedReader(fileReader);
        String CurrentData = "";
        while((bufferedReader.readLine()) != null) {
                line = CurrentData;
                bw.write(CurrentData);
                ((BufferedWriter) bw).newLine();
        }
        bw.write(Details);
        System.out.println("Account created!");

        System.out.println(name + " Your card number is: " + CardNo);
        //  close the reader.
        bufferedReader.close();
        //Close the writer.
        bw.close();

文件所需的输出是文件中任何地方都没有空白行，写入文件几次后对文件的实际输出如下所示：

Answer 1

这段代码错了：

String CurrentData = "";
while((bufferedReader.readLine()) != null) {
    line = CurrentData;
    bw.write(CurrentData);
    ((BufferedWriter) bw).newLine();
}

CurrentData（顺便说一句，变量应该以小写字母开头）总是""（空字符串），所以你什么都不写，然后是新的行字符。

while((currentData=bufferedReader.readLine()) != null) {...}

应该有效