com.nary.util.LogFileObject.java Source code

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Here is the source code for com.nary.util.LogFileObject.java

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/* 
 *  Copyright (C) 2000 - 2010 TagServlet Ltd
 *
 *  This file is part of Open BlueDragon (OpenBD) CFML Server Engine.
 *  
 *  OpenBD is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  Free Software Foundation,version 3.
 *  
 *  OpenBD is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *  
 *  You should have received a copy of the GNU General Public License
 *  along with OpenBD.  If not, see http://www.gnu.org/licenses/
 *  
 *  Additional permission under GNU GPL version 3 section 7
 *  
 *  If you modify this Program, or any covered work, by linking or combining 
 *  it with any of the JARS listed in the README.txt (or a modified version of 
 *  (that library), containing parts covered by the terms of that JAR, the 
 *  licensors of this Program grant you additional permission to convey the 
 *  resulting work. 
 *  README.txt @ http://www.openbluedragon.org/license/README.txt
 *  
 *  http://www.openbluedragon.org/
 */

package com.nary.util;

import java.io.IOException;
import java.util.Enumeration;
import java.util.Hashtable;

import org.apache.commons.vfs.FileObject;
import org.apache.commons.vfs.RandomAccessContent;
import org.apache.commons.vfs.util.RandomAccessMode;

import com.naryx.tagfusion.cfm.engine.cfEngine;

/**
 * This class provides an easy way for an application to maintain a log file
 * that is unique to it.
 * 
 * The logfile has an auto-rotation facility, initially set at 25MB
 */

public class LogFileObject extends Object {
    private static final String LOG_DATE_FORMAT = "dd/MM/yy HH:mm.ss: ";

    private RandomAccessContent outFileRandomAccess;
    private long logFileSize = 0;
    private FileObject filename;

    private static long maxLogFileSize = 25000000; // - default to 25MB
    private static Hashtable logfiles = new Hashtable();

    private LogFileObject(FileObject logPath) throws Exception {
        filename = logPath;

        if (!logPath.exists())
            logPath.createFile();

        outFileRandomAccess = logPath.getContent().getRandomAccessContent(RandomAccessMode.READWRITE);
        logFileSize = outFileRandomAccess.length();
        outFileRandomAccess.seek(logFileSize);
    }

    private void println(String _line) {
        try {
            writeData(com.nary.util.Date.formatNow(LOG_DATE_FORMAT) + _line + "\r\n");
        } catch (Exception e) {
            // DateFormat.format() has been observed to throw NullPointerExceptions
            cfEngine.log("Error " + e + " formatting date in LogFile.println( String _line )");
        }
    }

    private void close() {
        try {
            outFileRandomAccess.close();
        } catch (Exception E) {
        }
    }

    private synchronized void writeData(String _line) {
        try {
            outFileRandomAccess.writeBytes(_line);
            logFileSize += _line.length();
        } catch (IOException EE) {
        }

        if (logFileSize > maxLogFileSize)
            rotateLogFile();
    }

    private void rotateLogFile() {
        try {
            outFileRandomAccess.close();

            // rename the old file to a new one
            int x = 1;
            String sfname = filename.getName().getBaseName();
            FileObject newFile = filename.getParent().resolveFile(sfname + "." + x);

            while (newFile.exists()) {
                newFile = filename.getParent().resolveFile(sfname + "." + (x++));
            }

            filename.moveTo(newFile);

            //Delete the old one
            filename.delete();
            filename.createFile();

            outFileRandomAccess = filename.getContent().getRandomAccessContent(RandomAccessMode.READWRITE);
            ;
            logFileSize = 0;

        } catch (IOException ignoreException) {
            // - the rotation failed; so lets just reset the current file
        }
    }

    // -------------------------------------------------------

    public static void println(FileObject outFile, String _Line) {
        String key = outFile.toString();

        if (!logfiles.containsKey(key)) {
            try {
                logfiles.put(key, new LogFileObject(outFile));
            } catch (Exception E) {
                return;
            }
        }

        ((LogFileObject) (logfiles.get(key))).println(_Line);
    }

    public static void closeAll() {
        Enumeration E = logfiles.elements();
        while (E.hasMoreElements())
            ((LogFileObject) E.nextElement()).close();
    }
}