文件夹监视器Java代码打印报告两次
问题描述:
使用本网站的一些答案我创建了一个Java文件夹监视器应用程序。它应该检查对特定文件夹的更改并将这些更改输出到文本文件。不幸的是,每次更改都会打印报告两次。问题是我无法弄清楚报告的第一行来自哪里。请帮我理解我做错了什么。文件夹监视器Java代码打印报告两次
请找到下面的代码。我删除了代码的一部分,因为它不影响第q & A.
import java.io.File;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.apache.commons.io.monitor.FileAlterationListener;
import org.apache.commons.io.monitor.FileAlterationListenerAdaptor;
import org.apache.commons.io.monitor.FileAlterationMonitor;
import org.apache.commons.io.monitor.FileAlterationObserver;
public class FolderMonitor {
public FolderMonitor() {}
//path to a folder you are monitoring
public static final String FOLDER = "D:\\WatchedDir";
public static void main(String[] args) throws Exception
{
System.out.println("monitoring started");
// The monitor will perform polling on the folder every 5 seconds
final long pollingInterval = 6 * 1000;
// Let's get a directory as a File object and sort all its files.
File folderToMonitor = new File(FOLDER);
File outputFile = new File("H:\\Dir_changes.txt");
if (!folderToMonitor.exists())
{
// Test to see if monitored folder exists
throw new RuntimeException("Directory not found: " + FOLDER);
}
FileAlterationObserver observer = new FileAlterationObserver(folderToMonitor);
FileAlterationMonitor monitor = new FileAlterationMonitor(pollingInterval);
FileAlterationListener listener = new FileAlterationListenerAdaptor()
{
// Is triggered when a file in the monitored folder is modified from
@Override
public void onFileChange(File file)
{
// "file" is the reference to the newly created file
try {writeToFile(outputFile, convertLongToDate(outputFile.lastModified()), ("File modified: "+ file.getCanonicalPath()));}
catch (IOException e) {e.printStackTrace();}
}
};
observer.addListener(listener);
monitor.addObserver(observer);
monitor.start();
}
private static void writeToFile(File filePath, String timeStamp, String caughtChange) throws IOException
{
FileWriter fileWriter = new FileWriter(filePath,true);
BufferedWriter bufferFileWriter = new BufferedWriter(fileWriter);
fileWriter.append("\r" + timeStamp + " - " + caughtChange + "\r");
bufferFileWriter.close();
}
private static String convertLongToDate(long input)
{
Date date = new Date(input);
Calendar cal = new GregorianCalendar();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MMM/dd hh:mm:ss z");
sdf.setCalendar(cal);
cal.setTime(date);
return sdf.format(date);
}
}
输出看起来是这样的:
1454622374878文件修改:d:\ WatchedDir \秒\ inside3.txt 2016 /月/ 04 4点46分25秒EST - 文件修改:d:\ WatchedDir \秒\ inside3.txt
我想不通的地方突出显示(黑体)一部分来自于如何得到 摆脱它。请帮忙!
答
我运行了与您发布的代码相同的代码,并且在.txt文件中看不到额外的输出。您可以请尝试通过将输出导向到一个新文件,看看它是否有任何区别
答
由于某些原因,Eclipse正在执行代码,我已经从类中删除并保存更改。
当我重新启动Eclipse并再次执行代码后,一切都运行正常(惊喜)。
我曾考虑过删除这篇文章,但我决定留下它以防万一有人在寻找这样一段代码。我将留给主持人决定是否应该删除这个问题。
谢谢您花时间检查! – indigo