JAVA中的log4j的使用
前段时间使用log4j 来控制项目的日志输出，今天总结一下
我项目里面使用的是log4j.properties 配置文件
按大小生成一个日志文件
log4j.appender.logfile=org.apache.log4j.RollingFileAppender
log4j.appender.logfile.File=logs/keyservice.log
log4j.appender.logfile.Append=true
log4j.appender.logfile.MaxFileSize=100KB
log4j.appender.logfile.MaxBackupIndex=5
log4j.appender.logfile.layout=org.apache.log4j.PatternLayout
log4j.appender.logfile.layout.ConversionPattern=%d %p %F:%L [%t] - %m%n
具体解释网上都有，例如上面的是每100KB 生成一个日志文件，RollingFileAppender 这个类就是识别按大小生成日志文件
按日期一天生产一个日志文件
log4j.appender.logfile=org.apache.log4j.DailyRollingFileAppender
log4j.appender.logfile.File=logs/service.log
#log4j.appender.logfile.DatePattern=_yyyy-MM-dd’.log’
log4j.appender.logfile.DatePattern=_yyyy-MM-dd-HH-mm’.log’
log4j.appender.logfile.Append=true
log4j.appender.logfile.Threshold=DEBUG
log4j.appender.logfile.layout=org.apache.log4j.PatternLayout
log4j.appender.logfile.layout.ConversionPattern=%d %p %F:%L [%t] - %m%n
这是DailyRollingFileAppender 是识别一天生产一个日志文件
DatePattern 是输出日志文件的格式
上面两种情况合并
一般一天产生只一个文件，但当文件大小超过一定大小，一天就会生产多个文件。
我们可以看一下RollingFileAppender 和 DailyRollingFileAppender 两个类 都是继承FileAppender
我们只要重写一个类继承FileAppender 在此类中重写逻辑， 在配置文件直接引用即可
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 Log4JDateAndSizeSplit 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 Log4JDateAndSizeSplit() {
}
/**
* ouput destination for this appender.
*/
public Log4JDateAndSizeSplit(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);
}
}
*/
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Locale;
import java.util.TimeZone;
/**
*/
class RollingCalendar extends GregorianCalendar {
private static final long serialVersionUID = -3560331770601814177L;
int type = Log4JDateAndSizeSplit.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 Log4JDateAndSizeSplit.TOP_OF_MINUTE:
this.set(Calendar.SECOND, 0);
this.set(Calendar.MILLISECOND, 0);
this.add(Calendar.MINUTE, 1);
break;
case Log4JDateAndSizeSplit.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 Log4JDateAndSizeSplit.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 Log4JDateAndSizeSplit.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 Log4JDateAndSizeSplit.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 Log4JDateAndSizeSplit.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();
}
}
在配置文件里面直接引用这个重写的类，即可 ，
两种情况整合我也是借鉴网上其他资源。在我本地能够使用。
不过感觉log4j 也有点不好用，可尝试其他记录日志的方法。
一个properties 产生多种日志文件
首先在对应的代码需要日志的类中添加
private static final Log log1 = LogFactory.getLog("errorTest");
private static final Log log2 = LogFactory.getLog("Test");
log4j.logger.errorTest=DEBUG, error
#设为false就不会输出到其它地方 只会在这个一个日志文件输出，不会到总的文件中 默认可以
log4j.additivity.error=false
log4j.appender.error=com.util.Log4JDateAndSizeSplit
log4j.appender.error.Threshold=INFO
log4j.appender.error.ImmediateFlush=true
log4j.appender.error.File=logs/error.log
log4j.appender.error.Append=true
log4j.appender.error.MaxFileSize=10MB
log4j.appender.error.MaxBackupIndex=-1
log4j.appender.error.layout=org.apache.log4j.PatternLayout
log4j.appender.error.layout.ConversionPattern=%d [%5p] - %c -%F(%L) -%m%n
log4j.logger.Test=DEBUG,testDemo
#设为false就不会输出到其它地方 只会在这个一个日志文件输出，不会到总的文件中 默认可以
log4j.additivity.testDemo=false
log4j.appender.testDemo=com.util.Log4JDateAndSizeSplit
log4j.appender.testDemo.Threshold=INFO
log4j.appender.testDemo.ImmediateFlush=true
log4j.appender.testDemo.File=logs/test.log
log4j.appender.testDemo.Append=true
log4j.appender.testDemo.MaxFileSize=100MB
log4j.appender.testDemo.MaxBackupIndex=-1
log4j.appender.testDemo.layout=org.apache.log4j.PatternLayout
log4j.appender.testDemo.layout.ConversionPattern=%d{
yyyy-MM-dd hh:mm:ss} [%5p] -%m%n
注意看一下
log4j.logger.errorTest
和