關於log4j日志擴展—自定義PatternLayout

log4j日志擴展—PatternLayout

目前擴展log4j的日志一般使用擴展adaper的方法,這裡使用一種擴展PatternLayout方法。

log4j.rootLogger=debug, stdout, R
 
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
 
# Pattern to output the caller's file name and line number.
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] (%F:%L) - %m%n
log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=example.log
log4j.appender.R.MaxFileSize=100KB
# Keep one backup file
log4j.appender.R.MaxBackupIndex=1
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%n

這是log4j官網上的配置

請註意:

log4j.appender.stdout=org.apache.log4j.ConsoleAppender 
log4j.appender.R.layout=org.apache.log4j.PatternLayout

註意到其實這是兩個類

那麼org.apache.log4j.ConsoleAppender可以自定義,思考是否可以自定義log4j.appender.R.layout=org.apache.log4j.PatternLayout

下載官方文件發現有這樣兩個類

/*
 * 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 examples; 
import org.apache.log4j.*;
import org.apache.log4j.helpers.PatternParser;
 
/**
  Example showing how to extend PatternLayout to recognize additional
  conversion characters.  
  
  <p>In this case MyPatternLayout recognizes %# conversion pattern. It
  outputs the value of an internal counter which is also incremented
  at each call.
  <p>See <a href=doc-files/MyPatternLayout.java><b>source</b></a> code
  for more details.
  @see MyPatternParser
  @see org.apache.log4j.PatternLayout
  @author Anders Kristensen 
*/
public class MyPatternLayout extends PatternLayout {
  public
  MyPatternLayout() {
    this(DEFAULT_CONVERSION_PATTERN);
  }
 
  public
  MyPatternLayout(String pattern) {
    super(pattern);
  }
    
  public
  PatternParser createPatternParser(String pattern) {
    return new MyPatternParser(
      pattern == null ? DEFAULT_CONVERSION_PATTERN : pattern);
  }
  
  public
  static void main(String[] args) {
    Layout layout = new MyPatternLayout("[counter=%.10#] - %m%n");
    Logger logger = Logger.getLogger("some.cat");
    logger.addAppender(new ConsoleAppender(layout, ConsoleAppender.SYSTEM_OUT));
    logger.debug("Hello, log");
    logger.info("Hello again...");    
  }
}
/*
 * 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 examples; 
import org.apache.log4j.helpers.FormattingInfo;
import org.apache.log4j.helpers.PatternConverter;
import org.apache.log4j.helpers.PatternParser;
import org.apache.log4j.spi.LoggingEvent;
 
/**
  Example showing how to extend PatternParser to recognize additional
  conversion characters.  The examples shows that minimum and maximum
  width and alignment settings apply for "extension" conversion
  characters just as they do for PatternLayout recognized characters.
  
  <p>In this case MyPatternParser recognizes %# and outputs the value
  of an internal counter which is also incremented at each call.
  See <a href=doc-files/MyPatternParser.java><b>source</b></a> code
   for more details.
  
  @see org.apache.log4j.examples.MyPatternLayout
  @see org.apache.log4j.helpers.PatternParser
  @see org.apache.log4j.PatternLayout
  @author Anders Kristensen 
*/
public class MyPatternParser extends PatternParser { 
  int counter = 0; 
  public
  MyPatternParser(String pattern) {
    super(pattern);
  }
    
  public
  void finalizeConverter(char c) {
    if (c == '#') {
      addConverter(new UserDirPatternConverter(formattingInfo));
      currentLiteral.setLength(0);
    } else {
      super.finalizeConverter(c);
    }
  }
  
  private class UserDirPatternConverter extends PatternConverter {
    UserDirPatternConverter(FormattingInfo formattingInfo) {
      super(formattingInfo);
    }
 
    public
    String convert(LoggingEvent event) {
      return String.valueOf(++counter);
    }
  }  
}

直接粘過去找個類測試一下發現是可以使用的,顯示打印日志的行數

發現MyPatternLayout基本調用的是父類的方法

繼續扒

 public
  void finalizeConverter(char c) {
    if (c == '#') {
      addConverter(new UserDirPatternConverter(formattingInfo));
      currentLiteral.setLength(0);
    } else {
      super.finalizeConverter(c);
    }
  }

註意看這段代碼

發現字符為”#”的時候,創建瞭UserDirPatternConverter

推薦大傢去看PatternParser這裡面有答案

給大傢舉個例子

%#{MMMM}

使用extractOption()可以獲得MMMM

有瞭MMMM是不是就可以處理很多問題.

想一下,比如我們要在日志裡面打印公司的編號 orgId

那麼首先配置

log4j.appender.R.layout.ConversionPattern= %#{orgId}  %p %t %c - %m%n

這樣的話

if (c == '#') {
            String exs = super.extractOption();  //獲取orgId
            addConverter(new ExrPatternConverter(formattingInfo, exs));
            currentLiteral.setLength(0); 
        } else {
            super.finalizeConverter(c);
        }

考慮orgId的賦值問題

使用ThreadLocal

故完整的代碼

package com.yogapay.core; 
import java.util.HashMap;
import java.util.Map; 
import org.apache.log4j.helpers.FormattingInfo;
import org.apache.log4j.helpers.PatternConverter;
import org.apache.log4j.helpers.PatternParser;
import org.apache.log4j.spi.LoggingEvent; 
public class ExPatternParser extends PatternParser {
 
 static final ThreadLocal<Map<String, Object>> TH_LOCAL = new ThreadLocal<Map<String, Object>>(){
  @Override
        protected HashMap<String, Object> initialValue() {
            return new HashMap<String, Object>();
        } 
 };
 
 public static void setCurrentValue(String key, Object value) {
  Map<String, Object> map = TH_LOCAL.get();
  map.put(key, value);  
 }
 
 public ExPatternParser(String pattern) {
  super(pattern);
 }
 
 public void finalizeConverter(char c) {
  if (c == '#') {
   String exs = super.extractOption();
   addConverter(new ExrPatternConverter(formattingInfo, exs));
   currentLiteral.setLength(0); 
  } else {
   super.finalizeConverter(c);
  }
 }
 
 private class ExrPatternConverter extends PatternConverter { 
  private String cfg; 
  ExrPatternConverter(FormattingInfo formattingInfo, String cfg) {
   super(formattingInfo);
   this.cfg = cfg;
  }
 
  public String convert(LoggingEvent event) {
   Map<String, Object> valueMap = TH_LOCAL.get();
   if (valueMap != null) {
    Object value = valueMap.get(cfg);
    if (value != null) {
     return String.valueOf(value);
    }
   }
   return "";
  }
 }
}
package com.yogapay.core; 
import org.apache.log4j.*;
import org.apache.log4j.helpers.PatternParser; 
public class ExPatternLayout extends PatternLayout {
 public ExPatternLayout() {
  this(DEFAULT_CONVERSION_PATTERN);
 }
 
 public ExPatternLayout(String pattern) {
  super(pattern);
 } 
        @Override
 public PatternParser createPatternParser(String pattern) {
  return new ExPatternParser(pattern == null ? DEFAULT_CONVERSION_PATTERN : pattern);
 }
}
### set log levels ###
log4j.rootLogger = info,stdout
 
### 輸出到控制臺 ###
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.layout = com.yogapay.core.ExPatternLayout
log4j.appender.stdout.layout.ConversionPattern = lgcNo:%#{orgId} %d{yyyy-MM-dd HH:mm:ss} [%t] %p [%c] - %m%n

到此擴展就完成呢!

擴展log4j—自定義日志文件創建

之前使用過logstash,發現它的文件寫入功能比log4j更加完善

logstash允許動態創建文件夾,我隻使用瞭按照日期創建日志文件

如果配置日志路徑如下

/home/log/log/%{yyyy}/%{MM}/%{dd}-log.log

那麼就會創建路徑為/home/log/log/2018/06/12-log.log的文件

log4j有個DailyRollingFileAppender,支持按一定時間規則寫入日志,但是創建規則是在原有的日志文件之後加上時間後綴,這樣所有日志文件都在一個文件夾,非常不友好

因此,我自定義瞭appender,允許創建文件夾的方式存儲日志文件,每天凌晨寫入新的日志文件

內容如下

import org.apache.log4j.spi.LoggingEvent; 
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
/**
 * @author 墨盒
 */
public class EveryDayRollingFileAppender extends FileAppender { 
    private SimpleDateFormat format;
    private String fileName; 
    private Level level; 
    private static final String SEPERTOR = "-";
    private String regex = "\\{([^\\{\\}]+)\\}";// 
    private long next; 
    private Date now; 
    public Level getLevel() {
        return level;
    }
 
    public void setLevel(Level level) {
        this.level = level;
    }
 
    public EveryDayRollingFileAppender() {
        now = new Date();
        level = Level.WARN;
    }
 
 
    public String getFileName() {
        return fileName;
    }
 
    public void setFileName(String fileName) {
        this.fileName = fileName;
    }
 
    //TODO 18-6-16 該方法被調用瞭兩次
    @Override
    public void activateOptions() {
        Pattern pattern = Pattern.compile(regex);  
        Matcher matcher = pattern.matcher(fileName);
        StringBuilder builder = new StringBuilder();
        while (matcher.find()) {
            String temp = matcher.group(1); 
            builder.append(temp).append(SEPERTOR);
 
        }
        if (builder.length() != 0) {
            format = new SimpleDateFormat(builder.deleteCharAt(builder.length() - 1).toString());
            changeFile();
            setNextTime();日志采集小工具
        } else {
            format = null;
            try {
                setFile(fileName, getAppend(), getBufferedIO(), getBufferSize());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }  
    }
 
    private void changeFile() {
        if (format != null) {
            try {
                setFile(createFile(), getAppend(), getBufferedIO(), getBufferSize());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
 
    protected void setNextTime() {
        Calendar c = Calendar.getInstance();
        c.setTime(now);
        c.add(Calendar.DAY_OF_YEAR, 1);
        c.set(Calendar.MINUTE, 0);
        c.set(Calendar.HOUR, 0);
        c.set(Calendar.SECOND, 0);
        c.set(Calendar.MILLISECOND, 0);
        next = c.getTimeInMillis(); 
        System.out.println(new Date(next));
    } 
 
    @Override
    protected void subAppend(LoggingEvent event) {
        if (event.getLevel().syslogEquivalent <= level.syslogEquivalent) {
            long n = System.currentTimeMillis();
            if (n >= next) {
                now.setTime(n); 
                changeFile(); 
                setNextTime();  
            }
            super.subAppend(event);
        }
    }
 
    public String createFile() {
        String file = format.format(now); 
        String s[] = file.split(SEPERTOR); 
        String temp = fileName;
        for (int i = 0; i < s.length; i++) {
            temp = temp.replaceFirst(regex, s[i]);
        } 
 
        File f = new File(temp);
        if (!f.getParentFile().exists())
            f.getParentFile().mkdirs();
        else if (f.exists())
            f.delete(); 
        return f.getAbsolutePath(); 
    }
}

log4j配置如下

log4j.appender.logfile=org.apache.log4j.EveryDayRollingFileAppender
# 需要寫入的日志級別
log4j.appender.logfile.level=INFO
# 日志路徑
log4j.appender.logfile.fileName=/home/inkbox/log/log/{yyyy}/{MM}/{dd}_logSocket.log
log4j.appender.logfile.layout=org.apache.log4j.PatternLayout
log4j.appender.logfile.layout.ConversionPattern=%m%n

以上為個人經驗,希望能給大傢一個參考,也希望大傢多多支持WalkonNet。

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