rotatingfiletarget.java

基于Jabber协议的即时消息服务器

/*
 * Copyright (C) The Apache Software Foundation. All rights reserved.
 *
 * This software is published under the terms of the Apache Software License
 * version 1.1, a copy of which has been included with this distribution in
 * the LICENSE file.
 */
package org.jivesoftware.util.log.output.io.rotate;

import org.jivesoftware.util.log.format.Formatter;
import org.jivesoftware.util.log.output.io.FileTarget;
import java.io.File;
import java.io.IOException;

/**
 * This is a basic Output log target that writes to rotating files.
 *
 * @author <a href="mailto:[e-mail]">Peter Donald</a>
 * @author <a href="mailto:[e-mail]">Stephen McConnell</a>
 * @author <a href="mailto:[e-mail]">Bernhard Huber</a>
 */
public class RotatingFileTarget extends FileTarget {

    ///The rotation strategy to be used.
    private RotateStrategy m_rotateStrategy;

    ///The file strategy to be used.
    private FileStrategy m_fileStrategy;

    /**
     * Construct RotatingFileTarget object.
     *
     * @param formatter Formatter to be used
     */
    public RotatingFileTarget(final Formatter formatter,
                              final RotateStrategy rotateStrategy,
                              final FileStrategy fileStrategy)
            throws IOException {
        super(null, false, formatter);

        m_rotateStrategy = rotateStrategy;
        m_fileStrategy = fileStrategy;

        getInitialFile();
    }

    public synchronized void rotate()
            throws IOException {
        close();

        final File file = m_fileStrategy.nextFile();
        setFile(file, false);
        openFile();
    }

    /**
     * Output the log message, and check if rotation is needed.
     */
    public synchronized void write(final String data) {
        // send the log message
        super.write(data);

        // if rotation is needed, close old File, create new File
        final boolean rotate =
                m_rotateStrategy.isRotationNeeded(data, getFile());
        if (rotate) {
            try {
                rotate();
            }
            catch (final IOException ioe) {
                getErrorHandler().error("Error rotating file", ioe, null);
            }
        }
    }

    private void getInitialFile() throws IOException {
        close();

        boolean rotate = m_rotateStrategy.isRotationNeeded("", m_fileStrategy.currentFile());

        if (rotate) {
            setFile(m_fileStrategy.nextFile(), false);
        }
        else {
            setFile(m_fileStrategy.currentFile(), true);
        }

        openFile();
    }
}