log4j滚动输出压缩格式的文件

本片文章接演上一篇log4j 同时按日期和文件大小分割日志

因为需求需要，将原来默认切分生成的文件输出为压缩包的格式，不要源文件的格式，这样能节省存储空间。话不多说，下面为代码

（注：下面代码只是实现了在maxBackupIndex<0的情况下同时按照日期和文件大小输出压缩包gz的格式，以后可以做成灵活扩展，比如在配置文件里面配置，然后代码里去实现相应压缩包的生成，本文只是提供一种参考）：

package com.ihangmei.datapro.commons.logger;


import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
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 java.util.zip.GZIPOutputStream;

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;

/**
 * 目前滚动在maxBackupIndex可以生成无限个的条件下是以gz包的形式分割文件的
 * 后期可以扩展成定制化的兼容各种格式的文件，需要自己实现写入各类压缩包的代码
 * @author 
 *
 */

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;
    
    
    static final int BUFFER_GZIP = 1024 * 1024 * 2;//2M
    
    static final String SUFFIX_GZIP = ".gz";

    /**
     * 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 MyDailyRollingFileAppender() {
    }

    /**
     * ouput destination for this appender.
     */
    public MyDailyRollingFileAppender(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.
     * 

     * 

     * JavaBeans {@link java.beans.Introspector Introspector}.
     *
     * @see #setMaxFileSize(String)
     */
    public void setMaximumFileSize(long maxFileSize) {
        this.maxFileSize = maxFileSize;
    }

    /**
     * being rolled over to backup files.
     * 

     * 

     * the value "10KB" will be interpreted as 10240.
     */
    public void setMaxFileSize(String value) {
        maxFileSize = OptionConverter.toFileSize(value, maxFileSize + 1);
    }

    /**
     * Returns the value of the MaxBackupIndex option.
     */
    public int getMaxBackupIndex() {
        return maxBackupIndex;
    }

    /**
     * Set the maximum number of backup files to keep around.
     * 

     * 

     */
    public void setMaxBackupIndex(int maxBackups) {
        this.maxBackupIndex = maxBackups;
    }

    /**
     */
    public void setDatePattern(String pattern) {
        datePattern = pattern;
    }

    /**
     * Returns the value of the DatePattern 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())) + SUFFIX_GZIP;

        } 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.
     * 

     * 

     * If MaxBackupIndex is positive, then files {
     * 

     * 

     * 

     * If MaxBackupIndex is equal to zero, then the
     * File 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 + SUFFIX_GZIP);
                if (!target.exists()) { // Rename fileName to datedFilename.i
                    this.closeFile();
                    writeGzip(target);
//                    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 + SUFFIX_GZIP;
    }

    @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) + SUFFIX_GZIP;
        // 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();
        }

        writeGzip(target);
        
//        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;
    }

    /**
     * 

     * 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);

    }
    
    void writeGzip(File target){
    	
    	GZIPOutputStream out = null;
        FileInputStream fis = null;
        try {
        	fis = new FileInputStream(fileName);
        	out = new GZIPOutputStream(new FileOutputStream(target));
        	
        	int count=-1;
            byte data[] = new byte[BUFFER_GZIP];
            while ((count = fis.read(data, 0, BUFFER_GZIP)) != -1) {
            	out.write(data, 0, count);
            }
		}catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				if(fis != null){
					fis.close();
				}
				if(out != null){
					out.close();
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
    }
}