log4j 同时按日期和文件大小分割日志

重写源代码，可以将代码作为工具类使用（扩展FileAppender类）

package com.ihangmei.datareceive.commons;

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

import org.apache.log4j.FileAppender;
import org.apache.log4j.Layout;
import org.apache.log4j.helpers.CountingQuietWriter;
import org.apache.log4j.helpers.LogLog;
import org.apache.log4j.helpers.OptionConverter;
import org.apache.log4j.spi.LoggingEvent;

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 default maximum file size is 10MB.
*/
protected long maxFileSize = 10 * 1024 * 1024;

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

/**
* meaning daily rollover.
*/
private String datePattern = "'.'yyyy-MM-dd";

/**
* "scheduledFilename" at the beginning of the next hour.
*
*/
private String scheduledFilename;

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

Date now = new Date();

SimpleDateFormat sdf;

RollingCalendar rc = new RollingCalendar();

int checkPeriod = TOP_OF_TROUBLE;

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

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

/**
* ouput destination for this appender.
*/
public MyDailyRollingFileAppender(Layout layout, String filename, String datePattern) throws IOException
{
super(layout, filename, true);
this.datePattern = datePattern;
activateOptions();
}

/**
* being rolled over to backup files.
*
* @since 1.1
*/
public long getMaximumFileSize()
{
return maxFileSize;
}

/**
* being rolled over to backup files.
*
* <p>
* JavaBeans {@link java.beans.Introspector Introspector}.
*
* @see #setMaxFileSize(String)
*/
public void setMaximumFileSize(long maxFileSize)
{
this.maxFileSize = maxFileSize;
}

/**
* being rolled over to backup files.
*
* <p>
* the value "10KB" will be interpreted as 10240.
*/
public void setMaxFileSize(String value)
{
maxFileSize = OptionConverter.toFileSize(value, maxFileSize + 1);
}

/**
* Returns the value of the <b>MaxBackupIndex</b> option.
*/
public int getMaxBackupIndex()
{
return maxBackupIndex;
}

/**
* Set the maximum number of backup files to keep around.
*
* <p>
*/
public void setMaxBackupIndex(int maxBackups)
{
this.maxBackupIndex = maxBackups;
}

/**
*/
public void setDatePattern(String pattern)
{
datePattern = pattern;
}

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

@Override
public void activateOptions()
{
super.activateOptions();
if (datePattern != null && fileName != null)
{
now.setTime(System.currentTimeMillis());
sdf = new SimpleDateFormat(datePattern);
int type = computeCheckPeriod();
printPeriodicity(type);
rc.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 + "].");
}
}

// This method computes the roll over period by looping over the
// periods, starting with the shortest, and stopping when the r0 is
// different from from r1, where r0 is the epoch formatted according
// the datePattern (supplied by the user) and r1 is the
// epoch+nextMillis(i) formatted according to datePattern. All date
// formatting is done in GMT and not local format because the test
// logic is based on comparisons relative to 1970-01-01 00:00:00
// GMT (the epoch).

int computeCheckPeriod()
{
RollingCalendar rollingCalendar = new RollingCalendar(gmtTimeZone, Locale.ENGLISH);
// set sate to 1970-01-01 00:00:00 GMT
Date epoch = new Date(0);
if (datePattern != null)
{
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);
rollingCalendar.setType(i);
Date next = new Date(rollingCalendar.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...
}

/**
* Implements the usual roll over behaviour.
*
* <p>
* If <code>MaxBackupIndex</code> is positive, then files {

*
* <p>
* If <code>MaxBackupIndex</code> is equal to zero, then the
* <code>File</code> is truncated with no backup files created.
*/
public // synchronization not necessary since doAppend is alreasy synched
void sizeRollOver()
{
File target;
File file;

LogLog.debug("rolling over count=" + ((CountingQuietWriter) qw).getCount());
LogLog.debug("maxBackupIndex=" + maxBackupIndex);

String datedFilename = fileName + sdf.format(now);

if (maxBackupIndex > 0)
{
// Delete the oldest file, to keep Windows happy.
file = new File(datedFilename + '.' + maxBackupIndex);
if (file.exists())
file.delete();

// Map {(maxBackupIndex - 1), ..., 2, 1} to {maxBackupIndex, ..., 3,
// 2}
for (int i = maxBackupIndex - 1; i >= 1; i--)
{
file = new File(datedFilename + "." + i);
if (file.exists())
{
target = new File(datedFilename + '.' + (i + 1));
LogLog.debug("Renaming file " + file + " to " + target);
file.renameTo(target);
}
}

// Rename fileName to datedFilename.1
target = new File(datedFilename + "." + 1);

this.closeFile(); // keep windows happy.

file = new File(fileName);
LogLog.debug("Renaming file " + file + " to " + target);
file.renameTo(target);
}
else if (maxBackupIndex < 0)
{ // infinite number of files
// find the max backup index
for (int i = 1; i < Integer.MAX_VALUE; i++)
{
target = new File(datedFilename + "." + i);
if (!target.exists())
{ // Rename fileName to datedFilename.i
this.closeFile();
file = new File(fileName);
file.renameTo(target);
LogLog.debug("Renaming file " + file + " to " + target);
break;
}
}
}

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

@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);
}

/**
* Rollover the current file to a new file.
*/
void timeRollOver() 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);
}
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.
super.setFile(fileName, false, this.bufferedIO, this.bufferSize);
}
catch (IOException e)
{
errorHandler.error("setFile(" + fileName + ", false) call failed.");
}
scheduledFilename = datedFilename;
}

/**
*
* <p>
* rollover.
* */
@Override
protected void subAppend(LoggingEvent event)
{
long n = System.currentTimeMillis();

if (n >= nextCheck)
{
now.setTime(n);
nextCheck = rc.getNextCheckMillis(now);
try
{
timeRollOver();
}
catch (IOException ioe)
{
LogLog.error("rollOver() failed.", ioe);
}
}
else if ((fileName != null) && ((CountingQuietWriter) qw).getCount() >= maxFileSize)
{
sizeRollOver();
}
super.subAppend(event);

}
}

package com.ihangmei.datareceive.commons;

import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Locale;
import java.util.TimeZone;

/**
* ClassName:RollingCalendar <br/>
* Date: 2016年3月31日 上午11:41:34 <br/>
* @author lujie
* @version
* @see
*/
class RollingCalendar extends GregorianCalendar
{
private static final long serialVersionUID = -3560331770601814177L;

int type = MyDailyRollingFileAppender.TOP_OF_TROUBLE;

RollingCalendar()
{
super();
}

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

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

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

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

switch (type)
{
case MyDailyRollingFileAppender.TOP_OF_MINUTE:
this.set(Calendar.SECOND, 0);
this.set(Calendar.MILLISECOND, 0);
this.add(Calendar.MINUTE, 1);
break;
case MyDailyRollingFileAppender.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 MyDailyRollingFileAppender.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 MyDailyRollingFileAppender.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 MyDailyRollingFileAppender.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 MyDailyRollingFileAppender.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();
}
}

log4j.properties配置：

log4j.rootLogger=INFO,R

log4j.appender.R=com.ihangmei.datareceive.commons.MyDailyRollingFileAppender
log4j.appender.R.Threshold=INFO
log4j.appender.R.ImmediateFlush=true
log4j.appender.R.File=C:\\logs\\debug-logs\\test
log4j.appender.R.DatePattern='_'yyyy-MM-dd-HH-mm'.log'
log4j.appender.R.Append=true
log4j.appender.R.MaxFileSize=50KB
#MaxBackupIndex=-1(not limit about file number)
log4j.appender.R.MaxBackupIndex=-1
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%m%n

本文转载自：博客园文章：log4j 同时按日期和文件大小分割日志
还有另一篇文章参考：http://blog.csdn.net/szwangdf/article/details/37563307