当我尝试覆盖它时，文本文件变为空，当我重新启动操作系统时，其内容会恢复

Question

我正在尝试覆盖文本文件中的内容（作为编码程序的一部分），每当我运行代码时，文件都会变空，但是当我重新启动计算机时，内容会回到那里。
为什么会发生这种情况，我该如何解决这个问题？

fileScan = new Scanner(f);
fileWriter = new FileWriter(f);

while (fileScan.hasNext()) {
        //store current line
        curLine = fileScan.nextLine();
        curLineParsed = new char[curLine.length()];
        //parse into characters
        for (int i = 0; i < curLine.length(); i++)
            curLineParsed[i] = curLine.charAt(i);
        //reset new line
        newLine = "";

        //ENCODING ONE LINE
        //repeat for every code character
        for (int i = 0; i < code[0].length; i++) {
            //go through each character in the line
            for (int j = 0; j < curLineParsed.length; j++) {
                //if the character in process equals to the current character in line
                if (code[0][i] == curLineParsed[j]) {
                    //replace character
                    curLineParsed[j] = code[1][i];
                }
            }
        }

        //store it in a new string
        for (int i = 0; i < curLineParsed.length; i++)
            newLine += curLineParsed[i];
        System.out.println(newLine);

        //REPLACING ENCODED LINE WITH ORIGINAL
        fileWriter.write(newLine+"\n");
    }
    fileWriter.close();