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。
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