欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页

log4j DailyRollingFileAppender支持保留最近n天,并且可以对一天的文件根据大小切分

程序员文章站 2022-04-26 08:46:21
...

log4j DailyRollingFileAppender不支持只保留最近n天的数据,时间一久导致日志文件很多,并且一天的文件有可能比较大,所以自己写了个appender,以解决这两个问题。

    具体代码实现如下:

package com.mytools.common.log4jext;

import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.io.Writer;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Locale;
import java.util.TimeZone;

import org.apache.log4j.FileAppender;
import org.apache.log4j.Layout;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.PatternLayout;
import org.apache.log4j.helpers.CountingQuietWriter;
import org.apache.log4j.helpers.LogLog;
import org.apache.log4j.spi.LoggingEvent;

/**
 * log4j appender扩展<br>
 * (1)按天并且只保留最近n天的 <br>
 * (2)如果一天的文件过大,可以按配置的大小将一天的文件进行切分
 * 
 * @author shaoqz
 * @since 2016-6-13
 */
public class MyDailyRollingFileAppender extends FileAppender
{

	// The code assumes that the following constants are in a increasing
	// sequence.
	static final int TOP_OF_TROUBLE = -1;
	static final int TOP_OF_MINUTE = 0;
	static final int TOP_OF_HOUR = 1;
	static final int HALF_DAY = 2;
	static final int TOP_OF_DAY = 3;
	static final int TOP_OF_WEEK = 4;
	static final int TOP_OF_MONTH = 5;

	/**
	 * The gmtTimeZone is used only in computeCheckPeriod() method.
	 */
	public static final TimeZone gmtTimeZone = TimeZone.getTimeZone("GMT");

	/**
	 * The default maximum file size is 10MB. , 10K for test
	 */
	protected long maxFileSize = 10 * 1024;

	/**
	 * The date pattern. By default, the pattern is set to "'.'yyyy-MM-dd" meaning daily
	 * rollover.
	 */
	private String datePattern = "'.'yyyy-MM-dd";

	/**
	 * There is one backup file by default.
	 */
	private int maxBackupIndex = 1;

	/**
	 * The log file will be renamed to the value of the scheduledFilename variable when
	 * the next interval is entered. For example, if the rollover period is one hour, the
	 * log file will be renamed to the value of "scheduledFilename" at the beginning of
	 * the next hour. The precise time when a rollover occurs depends on logging activity.
	 */
	private String scheduledFilename;

	/**
	 * The next time we estimate a rollover should occur.
	 */
	private long nextCheck = System.currentTimeMillis() - 1;

	private Date now = new Date();

	private SimpleDateFormat sdf;

	private MyRollingCalendar rollingCalendar = new MyRollingCalendar();

	public int checkPeriod = TOP_OF_TROUBLE;

	/**
	 * The default constructor does nothing.
	 */
	public MyDailyRollingFileAppender()
	{
	}

	/**
	 * Instantiate a <code>DailyRollingFileAppender</code> and open the file designated by
	 * <code>filename</code>. The opened filename will become the ouput destination for
	 * this appender.
	 */
	public MyDailyRollingFileAppender(Layout layout, String filename, String datePattern) throws IOException
	{
		super(layout, filename, true);
		this.datePattern = datePattern;
		activateOptions();
	}

	/**
	 * The <b>DatePattern</b> takes a string in the same format as expected by
	 * {@link SimpleDateFormat}. This options determines the rollover schedule.
	 */
	public void setDatePattern(String pattern)
	{
		datePattern = pattern;
	}

	/** Returns the value of the <b>DatePattern</b> option. */
	public String getDatePattern()
	{
		return datePattern;
	}

	/**
	 * 设置日志文件最大备份数
	 * <p>
	 * The <b>MaxBackupIndex</b> option determines how many backup files are kept before
	 * the oldest is erased. This option takes a positive integer value. If set to zero,
	 * then there will be no backup files and the log file will be renamed to the value of
	 * the scheduledFilename variable when the next interval is entered.
	 */
	public void setMaxBackupIndex(int maxBackups)
	{
		this.maxBackupIndex = maxBackups;
	}

	/**
	 * 返回日志文件最大备份数
	 */
	public int getMaxBackupIndex()
	{
		return maxBackupIndex;
	}

	public void activateOptions()
	{
		super.activateOptions();

		LogLog.debug("Max backup file kept: " + maxBackupIndex + ".");

		if (datePattern != null && fileName != null)
		{
			now.setTime(System.currentTimeMillis());
			sdf = new SimpleDateFormat(datePattern);
			int type = computeCheckPeriod();
			printPeriodicity(type);
			rollingCalendar.setType(type);
			File file = new File(fileName);
			scheduledFilename = fileName + sdf.format(new Date(file.lastModified()));
		}
		else
		{
			LogLog.error("Either File or DatePattern options are not set for appender [" + name + "].");
		}
	}

	void printPeriodicity(int type)
	{
		switch (type)
		{
			case TOP_OF_MINUTE:
				LogLog.debug("Appender [[+name+]] to be rolled every minute.");
				break;
			case TOP_OF_HOUR:
				LogLog.debug("Appender [" + name + "] to be rolled on top of every hour.");
				break;
			case HALF_DAY:
				LogLog.debug("Appender [" + name + "] to be rolled at midday and midnight.");
				break;
			case TOP_OF_DAY:
				LogLog.debug("Appender [" + name + "] to be rolled at midnight.");
				break;
			case TOP_OF_WEEK:
				LogLog.debug("Appender [" + name + "] to be rolled at start of week.");
				break;
			case TOP_OF_MONTH:
				LogLog.debug("Appender [" + name + "] to be rolled at start of every month.");
				break;
			default:
				LogLog.warn("Unknown periodicity for appender [[+name+]].");
		}
	}

	int computeCheckPeriod()
	{
		MyRollingCalendar rollingPastCalendar = new MyRollingCalendar(gmtTimeZone, Locale.ENGLISH);
		// set sate to 1970-01-01 00:00:00 GMT
		Date epoch = new Date(0);

		if (datePattern == null)
		{
			return TOP_OF_TROUBLE;
		}

		for (int i = TOP_OF_MINUTE; i <= TOP_OF_MONTH; i++)
		{
			SimpleDateFormat simpleDateFormat = new SimpleDateFormat(datePattern);
			simpleDateFormat.setTimeZone(gmtTimeZone); // do all date formatting in
														// GMT
			String r0 = simpleDateFormat.format(epoch);
			rollingPastCalendar.setType(i);
			Date next = new Date(rollingPastCalendar.getNextCheckMillis(epoch));
			String r1 = simpleDateFormat.format(next);

			// System.out.println("Type = "+i+", r0 = "+r0+", r1 = "+r1);
			if (r0 != null && r1 != null && !r0.equals(r1))
			{
				return i;
			}
		}

		return TOP_OF_TROUBLE; // Deliberately head for trouble...
	}

	/**
	 * Rollover the current file to a new file.
	 */
	void rollOver() throws IOException
	{
		/* Compute filename, but only if datePattern is specified */
		if (datePattern == null)
		{
			errorHandler.error("Missing DatePattern option in rollOver().");
			return;
		}

		String datedFilename = fileName + sdf.format(now);
		// It is too early to roll over because we are still within the
		// bounds of the current interval. Rollover will occur once the
		// next interval is reached.
		if (scheduledFilename.equals(datedFilename))
		{
			return;
		}

		// close current file, and rename it to datedFilename
		this.closeFile();

		File target = new File(scheduledFilename);
		if (target.exists())
		{
			target.delete();
		}

		File file = new File(fileName);
		boolean result = file.renameTo(target);
		if (result)
		{
			LogLog.debug(fileName + " -> " + scheduledFilename);

			// If maxBackups <= 0, then there is no file renaming to be done.
			if (maxBackupIndex > 0)
			{
				// Delete the oldest file, to keep system happy.
				file = new File(fileName + dateBefore());

				// 删除很久以前的历史log文件
				deleteAncientFilesIfExists(file);

				if (file.exists())
				{
					file.delete();
				}
			}
		}
		else
		{
			LogLog.error("Failed to rename [[+fileName+]] to [[+scheduledFilename+]].");
		}

		try
		{
			// This will also close the file. This is OK since multiple close operations
			// are safe.
			this.setFile(fileName, false, this.bufferedIO, this.bufferSize);
		}
		catch (IOException e)
		{
			errorHandler.error("setFile(" + fileName + ", false) call failed.");
		}

		scheduledFilename = datedFilename;
	}

	/**
	 * 删除很久以前没有删除的日志文件(如果存在的话)
	 * 
	 * @param oldestFile
	 */
	private void deleteAncientFilesIfExists(final File oldestFile)
	{
		// 找出久远日志文件列表
		File[] ancientfiles = oldestFile.getParentFile().listFiles(new FileFilter()
		{

			@Override
			public boolean accept(File pathname)
			{
				if (pathname.getPath().replaceAll("\\\\", "/").startsWith(fileName.replaceAll("\\\\", "/"))
						&& pathname.getName().compareTo(oldestFile.getName()) < 0)
				{
					return true;
				}
				else
				{
					return false;
				}
			}
		});

		// 删除久远日志文件列表
		for (File ancientfile : ancientfiles)
		{
			// 如果文件比配置的最老日期还老的话,删掉
			ancientfile.delete();
		}
	}

	private String dateBefore()
	{
		String dataAnte = "";

		if (datePattern != null)
		{
			SimpleDateFormat simpleDateFormat = new SimpleDateFormat(datePattern);

			dataAnte = simpleDateFormat
					.format(new Date(rollingCalendar.getPastCheckMillis(new Date(), maxBackupIndex)));
		}

		return dataAnte;
	}

	/**
	 * This method differentiates DailyRollingFileAppender from its super class.
	 * <p>
	 * Before actually logging, this method will check whether it is time to do a
	 * rollover. If it is, it will schedule the next rollover time and then rollover.
	 */
	protected void subAppend(LoggingEvent event)
	{
		// 根据文件大小roll over
		rollOverBySize();

		// 根据时间roll over
		rollOverByTime();

		super.subAppend(event);
	}

	/**
	 * 根据文件大小roll over
	 */
	private void rollOverBySize()
	{
		long currentTimeMillis = System.currentTimeMillis();
		now.setTime(currentTimeMillis);

		if (fileName != null && qw != null)
		{
			long size = ((CountingQuietWriter) qw).getCount();
			if (size >= maxFileSize)
			{
				// close current file, and rename it
				this.closeFile();

				String rollingFileName = fileName + sdf.format(now) + '.' + currentTimeMillis;
				new File(fileName).renameTo(new File(rollingFileName));

				try
				{
					// This will also close the file. This is OK since multiple close
					// operations
					// are safe.
					this.setFile(fileName, false, this.bufferedIO, this.bufferSize);
				}
				catch (IOException e)
				{
					errorHandler.error("setFile(" + fileName + ", false) call failed.");
				}
			}
		}
	}

	/**
	 * 根据时间roll over
	 */
	private void rollOverByTime()
	{
		long currentTime = System.currentTimeMillis();

		if (currentTime < nextCheck)
		{
			return;
		}

		now.setTime(currentTime);
		nextCheck = rollingCalendar.getNextCheckMillis(now);

		try
		{
			rollOver();
		}
		catch (IOException ioe)
		{
			LogLog.error("rollOver() failed.", ioe);
		}
	}

	@Override
	public synchronized void setFile(String fileName, boolean append, boolean bufferedIO, int bufferSize)
			throws IOException
	{
		super.setFile(fileName, append, this.bufferedIO, this.bufferSize);
		if (append)
		{
			File f = new File(fileName);
			((CountingQuietWriter) qw).setCount(f.length());
		}
	}

	@Override
	protected void setQWForFiles(Writer writer)
	{
		this.qw = new CountingQuietWriter(writer, errorHandler);
	}

	/**
	 * 测试方法
	 */
	public static void main(String args[])
	{
		String className = MyDailyRollingFileAppender.class.getName();

		MyDailyRollingFileAppender myAppender = new MyDailyRollingFileAppender();

		myAppender.setDatePattern("'.'yyyy-MM-dd-HH");
		myAppender.setFile("E:/test/mylogApender/test.log");
		myAppender.setMaxBackupIndex(3);

		PatternLayout patternLayout = new PatternLayout("%d [%-5p]-[%t]-[%c{1}] (%F:%L) %m%n");
		myAppender.setLayout(patternLayout);

		System.out.println("getMaxBackupIndex():" + myAppender.getMaxBackupIndex());

		myAppender.activateOptions();

		for (int i = 0; i < 50000; i++)
		{
			myAppender.subAppend(new LoggingEvent(className, Logger.getLogger(className), Level.INFO,
					"test,hello " + i, null));

			try
			{
				Thread.sleep(100);
			}
			catch (InterruptedException ex)
			{
				ex.printStackTrace();
			}

			System.out.println("Fine attesa");
		}
	}
}

/**
 * MyRollingCalendar is a helper class to DailyMaxRollingFileAppender. Given a periodicity
 * type and the current time, it computes the past maxBackupIndex date.
 */
class MyRollingCalendar extends GregorianCalendar
{

	private static final long serialVersionUID = 1L;

	public static final int TOP_OF_TROUBLE = -1;
	public static final int TOP_OF_MINUTE = 0;
	public static final int TOP_OF_HOUR = 1;
	public static final int HALF_DAY = 2;
	public static final int TOP_OF_DAY = 3;
	public static final int TOP_OF_WEEK = 4;
	public static final int TOP_OF_MONTH = 5;

	int type = TOP_OF_TROUBLE;

	MyRollingCalendar()
	{
		super();
	}

	MyRollingCalendar(TimeZone tz, Locale locale)
	{
		super(tz, locale);
	}

	public long getPastCheckMillis(Date now, int maxBackupIndex)
	{
		return getPastDate(now, maxBackupIndex).getTime();
	}

	public Date getPastDate(Date now, int maxBackupIndex)
	{
		this.setTime(now);

		switch (type)
		{
			case TOP_OF_MINUTE:
				this.set(Calendar.MINUTE, this.get(Calendar.MINUTE) - maxBackupIndex);
				break;

			case TOP_OF_HOUR:
				this.set(Calendar.HOUR_OF_DAY, this.get(Calendar.HOUR_OF_DAY) - maxBackupIndex);
				break;

			case HALF_DAY:
				int hour = get(Calendar.HOUR_OF_DAY);
				if (hour < 12)
				{
					this.set(Calendar.HOUR_OF_DAY, 12);
				}
				else
				{
					this.set(Calendar.HOUR_OF_DAY, 0);
				}
				this.set(Calendar.DAY_OF_MONTH, this.get(Calendar.DAY_OF_MONTH) - maxBackupIndex);
				break;

			case TOP_OF_DAY:
				this.set(Calendar.DATE, this.get(Calendar.DATE) - maxBackupIndex);
				break;

			case TOP_OF_WEEK:
				this.set(Calendar.DAY_OF_WEEK, getFirstDayOfWeek());
				this.set(Calendar.WEEK_OF_YEAR, this.get(Calendar.WEEK_OF_YEAR) - maxBackupIndex);
				break;

			case TOP_OF_MONTH:
				this.set(Calendar.MONTH, this.get(Calendar.MONTH) - maxBackupIndex);
				break;

			default:
				throw new IllegalStateException("Unknown periodicity type.");
		}

		return this.getTime();
	}

	public long getNextCheckMillis(Date now)
	{
		return getNextCheckDate(now).getTime();
	}

	public Date getNextCheckDate(Date now)
	{
		this.setTime(now);

		switch (type)
		{
			case TOP_OF_MINUTE:
				this.set(Calendar.SECOND, 0);
				this.set(Calendar.MILLISECOND, 0);
				this.add(Calendar.MINUTE, 1);
				break;
			case TOP_OF_HOUR:
				this.set(Calendar.MINUTE, 0);
				this.set(Calendar.SECOND, 0);
				this.set(Calendar.MILLISECOND, 0);
				this.add(Calendar.HOUR_OF_DAY, 1);
				break;
			case HALF_DAY:
				this.set(Calendar.MINUTE, 0);
				this.set(Calendar.SECOND, 0);
				this.set(Calendar.MILLISECOND, 0);
				int hour = get(Calendar.HOUR_OF_DAY);
				if (hour < 12)
				{
					this.set(Calendar.HOUR_OF_DAY, 12);
				}
				else
				{
					this.set(Calendar.HOUR_OF_DAY, 0);
					this.add(Calendar.DAY_OF_MONTH, 1);
				}
				break;
			case TOP_OF_DAY:
				this.set(Calendar.HOUR_OF_DAY, 0);
				this.set(Calendar.MINUTE, 0);
				this.set(Calendar.SECOND, 0);
				this.set(Calendar.MILLISECOND, 0);
				this.add(Calendar.DATE, 1);
				break;
			case TOP_OF_WEEK:
				this.set(Calendar.DAY_OF_WEEK, getFirstDayOfWeek());
				this.set(Calendar.HOUR_OF_DAY, 0);
				this.set(Calendar.MINUTE, 0);
				this.set(Calendar.SECOND, 0);
				this.set(Calendar.MILLISECOND, 0);
				this.add(Calendar.WEEK_OF_YEAR, 1);
				break;
			case TOP_OF_MONTH:
				this.set(Calendar.DATE, 1);
				this.set(Calendar.HOUR_OF_DAY, 0);
				this.set(Calendar.MINUTE, 0);
				this.set(Calendar.SECOND, 0);
				this.set(Calendar.MILLISECOND, 0);
				this.add(Calendar.MONTH, 1);
				break;
			default:
				throw new IllegalStateException("Unknown periodicity type.");
		}
		return getTime();
	}

	void setType(int type)
	{
		this.type = type;
	}
}

 

使用时在appender配置的地方增加MaxBackupIndex配置即可。



 

相关标签: log4j java