DailyRollingFileAppender.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.log4j;
import java.io.IOException;
import java.io.File;
import java.io.InterruptedIOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Calendar;
import java.util.TimeZone;
import java.util.Locale;
import org.apache.log4j.helpers.LogLog;
import org.apache.log4j.spi.LoggingEvent;
/**
* DailyRollingFileAppender extends {@link FileAppender} so that the underlying file is rolled over at a user chosen
* frequency.
* <p>
* DailyRollingFileAppender has been observed to exhibit synchronization issues and data loss. The log4j extras
* companion includes alternatives which should be considered for new deployments and which are discussed in the
* documentation for org.apache.log4j.rolling.RollingFileAppender.
*
* <p>
* The rolling schedule is specified by the <b>DatePattern</b> option. This pattern should follow the
* {@link SimpleDateFormat} conventions. In particular, you <em>must</em> escape literal text within a pair of single
* quotes. A formatted version of the date pattern is used as the suffix for the rolled file name.
*
* <p>
* For example, if the <b>File</b> option is set to <code>/foo/bar.log</code> and the <b>DatePattern</b> set to
* <code>'.'yyyy-MM-dd</code>, on 2001-02-16 at midnight, the logging file <code>/foo/bar.log</code> will be copied to
* <code>/foo/bar.log.2001-02-16</code> and logging for 2001-02-17 will continue
* in <code>/foo/bar.log</code> until it rolls over the next day.
*
* <p>
* Is is possible to specify monthly, weekly, half-daily, daily, hourly, or minutely rollover schedules.
*
* <p>
* <table border="1" cellpadding="2">
* <tr>
* <th>DatePattern</th>
* <th>Rollover schedule</th>
* <th>Example</th>
*
* <tr>
* <td><code>'.'yyyy-MM</code>
* <td>Rollover at the beginning of each month</td>
*
* <td>At midnight of May 31st, 2002 <code>/foo/bar.log</code> will be copied to
* <code>/foo/bar.log.2002-05</code>. Logging for the month of June will be
* output to <code>/foo/bar.log</code> until it is also rolled over the next
* month.
*
* <tr>
* <td><code>'.'yyyy-ww</code>
*
* <td>Rollover at the first day of each week. The first day of the week depends
* on the locale.</td>
*
* <td>Assuming the first day of the week is Sunday, on Saturday midnight, June
* 9th 2002, the file <i>/foo/bar.log</i> will be copied to
* <i>/foo/bar.log.2002-23</i>. Logging for the 24th week of 2002 will be output
* to <code>/foo/bar.log</code> until it is rolled over the next week.
*
* <tr>
* <td><code>'.'yyyy-MM-dd</code>
*
* <td>Rollover at midnight each day.</td>
*
* <td>At midnight, on March 8th, 2002, <code>/foo/bar.log</code> will be copied
* to <code>/foo/bar.log.2002-03-08</code>. Logging for the 9th day of March
* will be output to <code>/foo/bar.log</code> until it is rolled over the next
* day.
*
* <tr>
* <td><code>'.'yyyy-MM-dd-a</code>
*
* <td>Rollover at midnight and midday of each day.</td>
*
* <td>At noon, on March 9th, 2002, <code>/foo/bar.log</code> will be copied to
* <code>/foo/bar.log.2002-03-09-AM</code>. Logging for the afternoon of the 9th
* will be output to <code>/foo/bar.log</code> until it is rolled over at
* midnight.
*
* <tr>
* <td><code>'.'yyyy-MM-dd-HH</code>
*
* <td>Rollover at the top of every hour.</td>
*
* <td>At approximately 11:00.000 o'clock on March 9th, 2002,
* <code>/foo/bar.log</code> will be copied to
* <code>/foo/bar.log.2002-03-09-10</code>. Logging for the 11th hour of the 9th
* of March will be output to <code>/foo/bar.log</code> until it is rolled over
* at the beginning of the next hour.
*
*
* <tr>
* <td><code>'.'yyyy-MM-dd-HH-mm</code>
*
* <td>Rollover at the beginning of every minute.</td>
*
* <td>At approximately 11:23,000, on March 9th, 2001, <code>/foo/bar.log</code>
* will be copied to <code>/foo/bar.log.2001-03-09-10-22</code>. Logging for the
* minute of 11:23 (9th of March) will be output to <code>/foo/bar.log</code>
* until it is rolled over the next minute.
*
* </table>
*
* <p>
* Do not use the colon ":" character in anywhere in the <b>DatePattern</b>
* option. The text before the colon is interpeted as the protocol specificaion
* of a URL which is probably not what you want.
*
* @author Eirik Lygre
* @author Ceki Gülcü
*/
public class DailyRollingFileAppender 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 date pattern. By default, the pattern is set to "'.'yyyy-MM-dd" meaning daily rollover.
*/
private String datePattern = "'.'yyyy-MM-dd";
/**
* 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.
* <p>
* 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;
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 DailyRollingFileAppender() {
}
/**
* 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 DailyRollingFileAppender(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;
}
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.getDefault());
// 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...
}
/**
* 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);
} 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, true, this.bufferedIO, this.bufferSize);
} catch (IOException e) {
errorHandler.error("setFile(" + fileName + ", true) call failed.");
}
scheduledFilename = datedFilename;
}
/**
* 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) {
long n = System.currentTimeMillis();
if (n >= nextCheck) {
now.setTime(n);
nextCheck = rc.getNextCheckMillis(now);
try {
rollOver();
} catch (IOException ioe) {
if (ioe instanceof InterruptedIOException) {
Thread.currentThread().interrupt();
}
LogLog.error("rollOver() failed.", ioe);
}
}
super.subAppend(event);
}
}
/**
* RollingCalendar is a helper class to DailyRollingFileAppender. Given a periodicity type and the current time, it
* computes the start of the next interval.
*/
class RollingCalendar extends GregorianCalendar {
private static final long serialVersionUID = -3560331770601814177L;
int type = DailyRollingFileAppender.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 DailyRollingFileAppender.TOP_OF_MINUTE:
this.set(Calendar.SECOND, 0);
this.set(Calendar.MILLISECOND, 0);
this.add(Calendar.MINUTE, 1);
break;
case DailyRollingFileAppender.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 DailyRollingFileAppender.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 DailyRollingFileAppender.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 DailyRollingFileAppender.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 DailyRollingFileAppender.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();
}
}