/**
* 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;
}
private String tempFileName=null;//这是我添加一个变量，用来记忆“log4j.appender.LOGFILE.File=./logs/logfile.log” public void activateOptions() {
if (datePattern != null && fileName != null) {
tempFileName=fileName;//把“./logs/logfile.log”附给tempFileName now.setTime(System.currentTimeMillis());
sdf = new SimpleDateFormat(datePattern);
int type = computeCheckPeriod();
printPeriodicity(type);
rc.setType(type);
File file = new File(fileName);
//--------------
我改动的地方------------------------
Date d=new Date();
if(file.exists())
{
d=new Date(file.lastModified());
}
scheduledFilename = fileName
+ sdf.format(d);//格式化文件名
setFile(scheduledFilename);//把格式化好的文件名，设置为日志文件名
now.setTime(System.currentTimeMillis());//设置当前日期
nextCheck = rc.getNextCheckMillis(now);//获取下次更新文件名的日期 //----------------------------------------------------
} else {
LogLog
.error("Either File or DatePattern options are not set for appender ["
+ name + "].");
}
super.activateOptions();//这个必须放到这最后，因为它里面会调用方法“this.setFile(datedFilename, false, this.bufferedIO, this.bufferSize);” }
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...
}
/**
* 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 =tempFileName+sdf.format(now);//当前的文件名 // 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(datedFilename);
if (target.exists()) {
target.delete();
}
//------------------------不需要这段代码-----------
// 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(datedFilename, false, this.bufferedIO, this.bufferSize);
} catch (IOException e) {
errorHandler.error("setFile(" + fileName + ", false) 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) {
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 {
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();
}
}
