Java 写入文本文件无法正常工作

Question

我支持的 Java 应用程序正在将一些详细信息记录在平面文件中。我有时面临的问题是，与前一天相比，入场人数非常低。此条目至关重要，因为我们的报告是根据该文件生成的。我编写代码时找不到任何问题。正在写入的方法是sync方法。

有什么建议吗？我还可以为您提供代码，您可能需要吗？

 public synchronized void log (String connID, String hotline, String callerType,
        String cli, String lastMenu, String lastInput,
        String status, String reason)
   {
    //String absoluteFP = LOG_LOC + ls + this.getFilename();

    //PrintWriter pw = this.getPrintWriter(absoluteFP, true, true);

    try
    {
        pw.print (this.getDateTime ()+ ","+connID +","+hotline+","+callerType+","+ cli+"," +   lastMenu + "," + lastInput + "," + status + "," + reason);               


        //end 1006
        pw.print (ls);
        pw.flush ();
        //pw.close();
    }
    catch (Exception e)
    {
        e.printStackTrace ();
        return;
    }
}

private synchronized PrintWriter getPrintWriter (String absoluteFileName,
        boolean append, boolean autoFlush)
{
    try
    {
        //set absolute filepath
        File folder = new File (absoluteFileName).getParentFile ();//2009-01-23

        File f = new File (absoluteFileName);

        if (!folder.exists ())//2009-01-23
        {
            //System.out.println ("Call Detailed Record folder NOT FOUND! Creating a new);     
            folder.mkdirs ();

            //System.out.println ("Configure log folder");
            this.setHiddenFile (LOG_LOC);//set tmp directory to hidden folder

            if (!f.exists ())
            {
                //System.out.println ("Creating a new Call Detailed Record...");//2009-01-23

                f.createNewFile ();//2009-01-23

                               }
        }
        else
        {
            if (!f.exists ())
            {
                //System.out.println ("Creating a new Call Detailed Record...");//2009-01-23

                f.createNewFile ();//2009-01-23


            }
        }

        FileOutputStream tempFOS = new FileOutputStream (absoluteFileName, append);
        if (tempFOS != null)
        {
            return new PrintWriter (tempFOS, autoFlush);
        }
        else
        {
            return null;
        }
    }
    catch (Exception ex)
    {
        ex.printStackTrace ();
        return null;
    }
}

          /**
             * Set the given absolute file path as a hidden file.
        * @param absoluteFile String
      */
     private void setHiddenFile (String absoluteFile)
       {
    //set hidden file
    //2009-01-22, KC
    Runtime rt = Runtime.getRuntime ();
    absoluteFile = absoluteFile.substring (0, absoluteFile.length () - 1);//2009-01-23
    try
    {
      System.out.println (rt.exec ("attrib +H " + "\"" + absoluteFile +        "\"").getInputStream ().toString ());
    }
    catch (IOException e)
    {
        e.printStackTrace ();
    }
}

private String getDateTime ()
{
    //2011-076-09, KC-format up to milliseconds to prevent duplicate PK in CDR table.
    //return DateUtils.now ("yyyy/MM/dd HH:mm:ss");
    return DateUtils.now ("yyyy/MM/dd HH:mm:ss:SSS");
    //end 0609
}

private String getFilename ()
{
    ///return "CDR_" + port + ".dat";//2010-10-01
    return port + ".dat";//2010-10-01
}

public void closePW ()
{
    if (pw != null)
    {
        pw.close ();
    }
}

Answer 1

您已经创建了 FileOutputStream ，但不会关闭该流。关闭该流并重试。这可能是导致问题的原因。

有时会记录消息，因为垃圾收集器会在某些时间间隔启动并关闭 FileOutStream 。这样就可以再次记录消息。由于您有 return，因此您收到了无法访问的错误。 if 中的声明& else block 。您必须调用 PrintWriter和FileOutStreamWriter出getPrintWriter将其放在您通常称为 getPrintWriter() 的位置。然后您将能够正确关闭流。 getPrintWriter应该只确保文件存在，因此将其重命名为 ensureFileExistance