java - Apache Commons IO Tailer 传送旧日志消息

Question

我的代码如下。

public static void main(String[] args) {
    // TODO code application logic here
    File pcounter_log = new File("c:\development\temp\test.log");

try {

    Tailer tailer = new Tailer(pcounter_log, new FileListener("c:\development\temp\test.log",getLogPattern()), 5000,true);

    Thread thread = new Thread(tailer);
    thread.start();
} catch (Exception e) {
    System.out.println(e);
}
}

public class FileListener extends TailerListenerAdapter {


 public void handle(String line) {
        for (String logPattern : pattern) {
            if (line.contains(logPattern)) {
                logger.info(line);

            }
        }
    }
}

此处 getLogPattern() 返回一个 ArrayList，其中包含 [info,error,abc.catch,warning] 等值。运行此代码时，我收到旧日志消息后跟新日志消息。 IE。输出是这样的:

20 May 2011 07:06:02,305  INFO FileListener:? - 20 May 2011 07:06:01,230 DEBUG   - exiting readScriptErrorStream()
20 May 2011 07:06:55,052  INFO FileListener:? - 20 May 2011 07:06:55,016 DEBUG  - readScriptErrorStream()
20 May 2011 07:06:56,056  INFO FileListener:? - 20 May 2011 07:06:55,040 DEBUG   - exiting readScriptErrorStream()
20 May 2011 07:07:01,241  INFO FileListener:? - 20 May 2011 07:07:01,219 DEBUG  - readScriptErrorStream()
20 May 2011 07:07:02,245  INFO FileListener:? -  20 May 2011 07:07:01,230 DEBUG   - exiting readScriptErrorStream()
20 May 2011 07:07:55,020  INFO FileListener:? -  20 May 2011 07:07:55,016 DEBUG  - readScriptErrorStream()
20 May 2011 07:07:56,024  INFO FileListener:? - 20  2011 07:07:55,030 DEBUG   - exiting readScriptErrorStream()
20 May 2011 07:08:01,269  INFO FileListener:? -  20 May 2011 07:08:01,227 DEBUG - readScriptErrorStream()
20 May 2011 07:08:02,273  INFO FileListener:? -  20 May 2011 07:08:01,230 DEBUG   - exiting readScriptErrorStream()
20 May 2011 07:08:21,234  INFO FileListener:? -  20 May 2011 06:40:02,461 DEBUG  - readScriptErrorStream()
20 May 2011 07:08:22,237  INFO FileListener:? -  20 May 2011 06:40:02,468 DEBUG   - exiting readScriptErrorStream()
20 May 2011 07:08:23,242  INFO FileListener:? -  20 May 2011 06:41:01,224 DEBUG - readScriptErrorStream()
20 May 2011 07:08:24,250  INFO FileListener:? -  20 May 2011 06:41:01,232 DEBUG   - exiting readScriptErrorStream()
20 May 2011 07:08:25,261  INFO FileListener:? -  20 May 2011 06:42:01,218 DEBUG  - readScriptErrorStream()
20 May 2011 07:08:26,265  INFO FileListener:? -  20 May 2011 06:42:01,230 DEBUG   - exiting readScriptErrorStream()
20 May 2011 07:08:27,272  INFO FileListener:? -  20 May 2011 06:43:01,223 DEBUG  - readScriptErrorStream()
20 May 2011 07:08:28,275  INFO FileListener:? -  20 May 2011 06:43:01,231 DEBUG   - exiting readScriptErrorStream()

如何避免像这样从日志文件中获取旧日志消息？

Answer 1

哦，天哪，我浪费了一整天的时间认为这是我狡猾的线程，但我现在看到其他人分享了我的痛苦。哦，好吧，至少我不会再浪费一天时间看它了。

但是我确实看过源代码。我确定错误发生在 Tailer.java 文件中:

boolean newer = FileUtils.isFileNewer(file, last); // IO-279, must be done first
...
...
else if (newer) {
    /*
    * This can happen if the file is truncated or overwritten with the 
    * exact same length of information. In cases like this, the file
    * position needs to be reset
    */
    position = 0;
    reader.seek(position);
...

似乎文件修改数据可能会在写入数据之前发生变化。我不是为什么会这样的专家。我正在从网络获取我的日志文件，所以可能正在进行各种缓存，这意味着您不能保证更新的文件将包含更多数据。

我已经更新了源代码并删除了这一部分。对我来说，文件被截断/重新创建的字节数完全相同的可能性很小。我引用的是 10MB 的滚动日志文件。

我看到这是一个已知问题 ( IO-279 LINK HERE )。但是，它被标记为已解决，但显然并非如此。我会联系开发人员，看看是否有什么正在筹备中。看起来他们对修复的看法与我相同。