自定义log4j日志文件命名规则说明

目录

• 自定义log4j日志文件命名规则
• 根据log4j的API定义自己的FileAppender
• 对应的log4j.properties的配置文件如下
• 输出的日志文件命名如下
• log4j自定义生成文件的名称
• log4j.properties
• MyRollingFileAppender.java

自定义log4j日志文件命名规则

项目中的日志需要采用一致的命名规范和文件规范，命名规则为：项目模块标识_index_日期时间_日志级别.log，且每个级别日志文件放在单独的文件夹，且每个文件夹下日志的数量不得超过10个，当数量超过限制时，删除相对较旧的日志，保留较新的日志。

但是发现log4j并不能满足此要求，于是

根据log4j的API定义自己的FileAppender

代码如下：

package com.dear.simpler.dbrpc.util.log;
import java.io.File;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Date;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.log4j.RollingFileAppender;
import org.apache.log4j.helpers.CountingQuietWriter;
import org.apache.log4j.helpers.LogLog;
import org.apache.log4j.spi.LoggingEvent;
/**;
 *
 * @author lixiang
 * 自定义log文件的命名规则
 */
public class MyLogFileAppender extends RollingFileAppender {
    private long nextRollover = 0;
    private static AtomicInteger logIndex = new AtomicInteger(0);    //index
    public void rollOver() {
        File file = null;  

        if (qw != null) {
            long size = ((CountingQuietWriter) qw).getCount();
            LogLog.debug("rolling over count=" + size);
            // if operation fails, do not roll again until
            // maxFileSize more bytes are written
            nextRollover = size + maxFileSize;
        }
        LogLog.debug("maxBackupIndex=" + maxBackupIndex);  

        if (maxBackupIndex > 0) {
            file = new File(getRollingFileName(fileName, logIndex.incrementAndGet()));
            if (fileExisted(file)){
            	file = new File(getRollingFileName(fileName, logIndex.incrementAndGet()));
            }
            deleteOldFile(file.getParentFile(), maxBackupIndex);
            this.closeFile();
        }
        try {
            this.setFile(getRollingFileName(fileName, logIndex.get()), false, bufferedIO, bufferSize);
            nextRollover = 0;
        } catch (IOException e) {
            if (e instanceof InterruptedIOException) {
            Thread.currentThread().interrupt();
        }
          LogLog.error("setFile(" + fileName + ", false) call failed.", e);
        }
    }  

    private String getRollingFileName(String fileName, int index) {     //使用正则表达式替代index
        Pattern p = Pattern.compile("_\\d+\\_");
        Matcher m=p.matcher(fileName);
        String str = m.replaceFirst(String.format("_%d_", index));
        SimpleDateFormat format = new SimpleDateFormat("yyyyMMddHHmmss");   //日期
        String dateString = format.format(new Date(System.currentTimeMillis()));
        str = str.replaceAll("\\d{14}", dateString);
        return str;
    }
    public synchronized void setFile(String fileName, boolean append,   //修改文件名
            boolean bufferedIO, int bufferSize) throws IOException {
    	SimpleDateFormat format = new SimpleDateFormat("yyyyMMddHHmmss");   //日期
        String dateString = format.format(new Date(System.currentTimeMillis()));
        String temp = String.format(fileName , dateString);   //文件名
        super.setFile(temp, append, bufferedIO, bufferSize);  

        if(append) {
            File f = new File(temp);
            ((CountingQuietWriter)this.qw).setCount(f.length());
        }
    }

    private boolean fileExisted(File file){
    	boolean res = false;
    	String[] fts = file.getName().split("_");
    	File parentFile = file.getParentFile();
    	for(File f : parentFile.listFiles()){
    		String[] fns = f.getName().split("_");
    		if(fns[0].equals(fts[0]) && fns[1].equals(fts[1])){
    			res = true;
    			break;
    		}
    	}
    	return res;
    }

    private void deleteOldFile(File dir , int maxInt){
    	if(getFileNum(dir) >= maxBackupIndex ){
        	File[] files = orderByDate(dir);
        	for (int i = 0; i <= files.length - maxBackupIndex; i++) {
				File f = files[i];
				f.delete();
			}
    	}
    }

    private int getFileNum(File file){
        	return file.list().length;
    }

    //将文件按日期排序
    public File[] orderByDate(File dir) {
       File[] fs = dir.listFiles();
       Arrays.sort(fs,new Comparator< File>(){
    	   @Override
    	   public int compare(File f1, File f2) {
    		   long diff = f1.lastModified() - f2.lastModified();
    		   if (diff > 0)
    			   return 1;
    		   else if (diff == 0)
    			   return 0;
    		   else
    			   return -1;
    	   }
    	   @Override
    	   public boolean equals(Object obj) {
    		   return true;
    	   }
         });
       return fs;
      }  

    @Override
    protected void subAppend(LoggingEvent event) {
        super.subAppend(event);
        if (fileName != null && qw != null) {
            long size = ((CountingQuietWriter) qw).getCount();
            if (size >= maxFileSize && size >= nextRollover) {
                rollOver();
            }
        }
    }
}  

对应的log4j.properties的配置文件如下

### set log levels ###
log4j.rootLogger = out,E,I
#log4j.logger.com.dear.simpler.dbrpc.util.log.TestUtil=out,D
log4j.appender.D = com.dear.simpler.dbrpc.util.log.MyLogFileAppender
log4j.appender.D.File = ../../logs/db_logs/debug/DB_0_%s_debug.log
log4j.appender.D.Append = true
log4j.appender.D.MaxFileSize=1024MB
log4j.appender.D.MaxBackupIndex=10
log4j.appender.D.Threshold = DEBUG
log4j.appender.D.layout = com.dear.simpler.dbrpc.util.log.ExPatternLayout
log4j.appender.D.layout.ConversionPattern = [%d{yyyy/MM/dd HH:mm:ss,SSS}][%T:%t][%p][%F:%L:%M][%m]%n
log4j.appender.E = com.dear.simpler.dbrpc.util.log.MyLogFileAppender
log4j.appender.E.File = ../../logs/db_logs/error/DB_0_%s_error.log
log4j.appender.E.Append = true
log4j.appender.E.MaxFileSize=10MB
log4j.appender.E.MaxBackupIndex=10
log4j.appender.E.Threshold = ERROR
log4j.appender.E.layout = com.dear.simpler.dbrpc.util.log.ExPatternLayout
log4j.appender.E.layout.ConversionPattern = [%d{yyyy/MM/dd HH:mm:ss,SSS}][%T:%t][%p][%F:%L:%M][%m]%n
log4j.appender.I = com.dear.simpler.dbrpc.util.log.MyLogFileAppender
log4j.appender.I.File = ../../logs/db_logs/info/DB_0_%s_info.log
log4j.appender.I.Append = true
log4j.appender.I.MaxFileSize=10MB
log4j.appender.I.MaxBackupIndex=10
log4j.appender.I.Threshold = INFO
log4j.appender.I.layout = com.dear.simpler.dbrpc.util.log.ExPatternLayout
log4j.appender.I.layout.ConversionPattern = [%d{yyyy/MM/dd HH:mm:ss,SSS}][%T:%t][%p][%F:%L:%M][%m]%n

输出的日志文件命名如下

log4j自定义生成文件的名称

我们在使用Log4j的RollingFileAppender循环生成文件的时候，生成的文件的名称有点儿恶心，例如，文件名称为app.log，那么生成的文件名依次为app.log.1,app.log.2,....

那么如何去改变生成文件的名称的规则呢？下面是一个简单示例：

log4j.properties

log4j.logger.major= INFO, majorMsg
log4j.additivity.logError = false
log4j.appender.majorMsg=com.zws.log.MyRollingFileAppender
log4j.appender.majorMsg.File=${catalina.home}/logs/itc/majorMsg.log
log4j.appender.majorMsg.layout=org.apache.log4j.PatternLayout
log4j.appender.majorMsg.layout.ConversionPattern=%d{yyyy-MM-dd HH\:mm\:ss}|%p|%C|%M|%L|%m%n
log4j.appender.majorMsg.MaxFileSize=1KB
log4j.appender.majorMsg.MaxBackupIndex=10

MyRollingFileAppender.java

package com.zws.log;
import java.io.File;
import java.io.IOException;
import java.io.InterruptedIOException;
import org.apache.log4j.Priority;
import org.apache.log4j.RollingFileAppender;
import org.apache.log4j.helpers.CountingQuietWriter;
import org.apache.log4j.helpers.LogLog;
import org.apache.log4j.spi.LoggingEvent;
/**
 *
 * @author wensh.zhu
 *
 */
public class MyRollingFileAppender extends RollingFileAppender {
 private long nextRollover = 0;
 public void rollOver() {
  File target;
  File file;
  if (qw != null) {
   long size = ((CountingQuietWriter) qw).getCount();
   nextRollover = size + maxFileSize;
  }
  LogLog.debug("maxBackupIndex=" + maxBackupIndex);
  boolean renameSucceeded = true;
  if (maxBackupIndex > 0) {
   //删除序号最大（最早的文件）的文件
   file = new File(genFileName(fileName, maxBackupIndex));
   if (file.exists())
    renameSucceeded = file.delete();
   //所有文件名序号加1
   for (int i = maxBackupIndex - 1; i >= 1 && renameSucceeded; i--) {
    file = new File(genFileName(fileName, i));
    if (file.exists()) {
     target = new File(genFileName(fileName, i + 1));
     renameSucceeded = file.renameTo(target);
    }
   }
   if (renameSucceeded) {
    target = new File(genFileName(fileName, 1));
    this.closeFile();
    file = new File(fileName);
    renameSucceeded = file.renameTo(target);
    if (!renameSucceeded) {
     try {
      this.setFile(fileName, true, bufferedIO, bufferSize);
     } catch (IOException e) {
      if (e instanceof InterruptedIOException) {
       Thread.currentThread().interrupt();
      }
      LogLog.error("setFile(" + fileName + ", true) call failed.", e);
     }
    }
   }
  }
  if (renameSucceeded) {
   try {
    this.setFile(fileName, false, bufferedIO, bufferSize);
    nextRollover = 0;
   } catch (IOException e) {
    if (e instanceof InterruptedIOException) {
     Thread.currentThread().interrupt();
    }
    LogLog.error("setFile(" + fileName + ", false) call failed.", e);
   }
  }
 }
 private String genFileName(String name, int index) {
  String fileName = "";
  if (index > 0) {
   String num = index < 10 ? "0" + index : String.valueOf(index);
   fileName = name.replace(".log", "") + "_" + num + ".log";
  } else {
   fileName = name;
  }
  return fileName;
 }

 protected void subAppend(LoggingEvent event) {
  super.subAppend(event);
  if (fileName != null && qw != null) {
   long size = ((CountingQuietWriter) qw).getCount();
   if (size >= maxFileSize && size >= nextRollover) {
    rollOver();
   }
  }
 }
}

以上示例将文件名的生成规则为：如果文件名为app.log，那么后续的文件为app_01.log,app_02.log.

仅为个人经验，希望能给大家一个参考，也希望大家多多支持我们