爲什麼寫入文件時，我的文件寫入器會留下不必要的行？

Question

我有一個filewriter（顯然）正在用於將用戶信息寫入文件;它寫得很好，程序運行良好，但是作者不會以所需的方式寫入文件。我注意到在寫入文件時，它會留下空白的行，有時我不想要這些行，我看不出爲什麼。以下是與文件寫入相關的代碼（它是文件中使用filewriter的唯一位置）。所有變量等都已被定義並正常工作。

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(); 

所需的輸出到文件裏沒有空行的文件中留下的任何地方，實際輸出到文件中寫入了幾次後，如下所示：

Answer 1

這段代碼是錯誤的：

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

CurrentData（順便說一句，變量應該以小寫開始）常是s（空字符串）""，所以你不寫任何東西，然後換行符。

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

應該工作