增強型Log4j使用方法 設置最大文件數、文件最大內存

可實現：每天生成新文件、可設置最大文件數、文件的最大內存等等.

項目中構建如下類，類名爲MyDailyRollingFileAppender  

import org.apache.log4j.FileAppender;
import org.apache.log4j.Layout;
import org.apache.log4j.helpers.LogLog;
import org.apache.log4j.spi.LoggingEvent;
 
import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;

public class MyDailyRollingFileAppender extends FileAppender {
 
    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;
 
    /**
     * 默認設置："'.'yyyy-MM-dd"
     * 設置說明：按天循環打印日誌
     */
    private String datePattern = "'.'yyyy-MM-dd-HH-mm";
 
    private int maxBackupIndex = 3;
 
    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;
 
    /**
     * 獲取當前環境所處的時區
     * 僅供computeCheckPeriod方法使用
     */
    static final TimeZone gmtTimeZone = TimeZone.getTimeZone("GMT");
 
    public MyDailyRollingFileAppender() {}
 
    public MyDailyRollingFileAppender(Layout layout, String filename, String datePattern)
        throws IOException {
        super(layout, filename, true);
 
        this.datePattern = datePattern;
        activateOptions();
    }
 
    public void setDatePattern(String pattern) {
        this.datePattern = pattern;
    }
 
    public String getDatePattern() {
        return datePattern;
    }
 
    public int getMaxBackupIndex() {
        return maxBackupIndex;
    }
 
    public void setMaxBackupIndex(int maxBackupIndex) {
        this.maxBackupIndex = maxBackupIndex;
    }
 
    /**
     * activateOptions譯名爲激活操作
     * 意思是按照配置的參數進行初始化
     * scheduledFilename爲log的最後一次修改時間
     */
    @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 + "].");
        }
    }
 
    /**
     * 根據type打印做出日誌打印
     * @param type
     */
    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() {
        RollingCalendar rollingCalendar = new RollingCalendar(gmtTimeZone, Locale.getDefault());
        // 設置初始時間爲格林尼治時間：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++ ) {
                // 將所示的時間格式化爲當前時區
                SimpleDateFormat simpleDateFormat = new SimpleDateFormat(datePattern);
                simpleDateFormat.setTimeZone(gmtTimeZone);
 
                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...
    }
 
    /**
     * 按照週期將當前日誌文件轉存爲日期文件
     *
     * @throws IOException
     */
    void rollOver()
        throws IOException {
 
        if (datePattern == null) {
            errorHandler.error("Missing DatePattern option in rollOver().");
            return;
        }
 
        String datedFilename = fileName + sdf.format(now);
 
        // 如果最後一次的修改時間爲當前時間 ，則不做任何任何操作
        if (scheduledFilename.equals(datedFilename)) {
            return;
        }
 
        // 關閉當前文件，重命名爲日期文件
        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 + "].");
        }
 
        // 獲取日誌文件列表，控制數量，實現清理策略
        if (file.getParentFile().exists()) {
            File[] files = file.getParentFile().listFiles((FileFilter)new LogFileFilter(file.getName()));
            Long[] dateArray = new Long[files.length];
            for (int i = 0; i < files.length; i++ ) {
                File fileItem = files[i];
                String fileDateStr = fileItem.getName().replace(file.getName(), "");
                Date filedate = null;
                try {
                    filedate = sdf.parse(fileDateStr);
                    long fileDateLong = filedate.getTime();
                    dateArray[i] = fileDateLong;
                }
                catch (ParseException e) {
                    LogLog.error("Parse File Date Throw Exception : " + e.getMessage());
                }
            }
            Arrays.sort(dateArray);
            if (dateArray.length > maxBackupIndex) {
                for (int i = 0; i < dateArray.length - maxBackupIndex; i++ ) {
                    String dateFileName = file.getPath() + sdf.format(dateArray[i]);
                    File dateFile = new File(dateFileName);
                    if (dateFile.exists()) {
                        dateFile.delete();
                    }
                }
            }
        }
 
        try {
            // This will also close the file. This is OK since multiple close operations are safe.
            this.setFile(fileName, true, this.bufferedIO, this.bufferSize);
        }
        catch (IOException e) {
            errorHandler.error("setFile(" + fileName + ", true) call failed.");
        }
        scheduledFilename = datedFilename;
    }
 
    /**
     * 寫入日誌之前判斷是否需要新起一個日誌來記錄
     */
    @Override
    protected void subAppend(LoggingEvent event) {
        long n = System.currentTimeMillis();
        if (n >= nextCheck) {
            now.setTime(n);
            nextCheck = rc.getNextCheckMillis(now);
            try {
                rollOver();
            }
            catch (IOException ioe) {
                if (ioe instanceof InterruptedIOException) {
                    Thread.currentThread().interrupt();
                }
                LogLog.error("rollOver() failed.", ioe);
            }
        }
        super.subAppend(event);
    }
}
 
 
/**
 * 文件過濾器
 *
 * @author Mike.Peng
 * @time Jan 12, 2016  5:28:31 PM
 */
class LogFileFilter implements FileFilter {
    private String logName;
 
    public LogFileFilter(String logName) {
        this.logName = logName;
    }
 
    @Override
    public boolean accept(File file) {
        if (logName == null || file.isDirectory()) {
            return false;
        }
        else {
            LogLog.debug(file.getName());
            return file.getName().startsWith(logName);
        }
    }
}
 
 
/**
 * MyDailyRollingFileAppender的內部類
 * 提供週期類型和當前時間 ，計算並返回下一個週期的開始時間
 *
 * @author Mike.Peng
 * @time Jan 12, 2016  5:28:48 PM
 */
class RollingCalendar extends GregorianCalendar {
    private static final long serialVersionUID = -3560331770601814177L;
 
    int type = MyDailyRollingFileAppender.TOP_OF_TROUBLE;
 
    /**
     * RollingCalendar默認構造器
     */
    RollingCalendar() {
        super();
    }
 
    /**
     * RollingCalendar構造器
     * 根據地點時區 ，獲取對應的日曆Calendar
     * @param tz
     * @param locale
     */
    RollingCalendar(TimeZone tz, Locale locale) {
        super(tz, locale);
    }
 
    void setType(int type) {
        this.type = type;
    }
 
    public long getNextCheckMillis(Date now) {
        return getNextCheckDate(now).getTime();
    }
 
    /**
     * 根據所傳入的時間以及時間類型獲取下一個時間
     * @param now
     * @return
     */
    public Date getNextCheckDate(Date now) {
        this.setTime(now);
 
        switch (type) {
            case MyDailyRollingFileAppender.TOP_OF_MINUTE:
                this.set(Calendar.SECOND, 0);
                this.set(Calendar.MILLISECOND, 0);
                this.add(Calendar.MINUTE, 1);
                break;
            case MyDailyRollingFileAppender.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 MyDailyRollingFileAppender.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 MyDailyRollingFileAppender.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 MyDailyRollingFileAppender.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 MyDailyRollingFileAppender.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log4j配置文件中 加入如下引用

log4j.appender.R=com.config.MyDailyRollingFileAppender

 

 

整體配置文件內容爲

log4j.rootCategory=INFO , R 
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss}  [%p]  %m%n
#log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R=com.config.MyDailyRollingFileAppender
log4j.appender.R.File=D://log//log1/log_
log4j.appender.R.DatePattern =yyyy-MM-dd'.log'
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss}  [%p]  %m%n
log4j.appender.R.MaxBackupIndex= 30
 
log4j.logger.com.opensymphony.oscache=WARN
log4j.logger.net.sf.navigator=WARN
log4j.logger.org.apache.commons=WARN
log4j.logger.org.apache.struts=WARN
log4j.logger.org.displaytag=WARN
log4j.logger.org.springframework=WARN
log4j.logger.org.apache.velocity=FATAL
 

 

至此  可實現最大文件數的設置。