PluginFileAppender.java

/*
 * JBoss, Home of Professional Open Source
 * Copyright 2005, JBoss Inc., and individual contributors as indicated
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.hibernate.eclipse.logging;

import java.io.IOException;

import org.apache.log4j.Layout;
import org.apache.log4j.RollingFileAppender;
import org.apache.log4j.spi.LoggingEvent;
import org.eclipse.core.runtime.IPath;
import org.hibernate.console.ConsoleMessages;

/**
 * PluginFileAppender
 * This class is a custom Log4J appender that sends Log4J events to
 * the Eclipse plug-in state location. It extends the RollingFileAppender class.
 * @author Manoel Marques
 */
public class PluginFileAppender extends RollingFileAppender {

	private IPath stateLocation;
	private boolean activateOptionsPending;
	private boolean translatePath = true;

	/**
	 * Creates a new PluginFileAppender.
	 */
	public PluginFileAppender() {
		super();
	}

	/**
	 * Creates a new PluginFileAppender.
	 * @param layout layout instance.
	 * @param stateLocation IPath containing the plug-in state location
	 */
	public PluginFileAppender(Layout layout,IPath stateLocation) {
		super();
		setLayout(layout);
		setStateLocation(stateLocation);
	}

	/**
	 * Creates a new PluginFileAppender.
	 * @param layout layout instance.
	 * @param stateLocation IPath containing the plug-in state location
	 * @param file file name
	 * @param append true if file is to be appended
	 */
	public PluginFileAppender(Layout layout,IPath stateLocation, String file, boolean append)
			throws IOException {
		super();
		setLayout(layout);
		setStateLocation(stateLocation);
		setFile(file);
		setAppend(append);
		activateOptions();
	}

	/**
	 * Creates a new PluginFileAppender.
	 * @param layout layout instance.
	 * @param stateLocation IPath containing the plug-in state location
	 * @param file file name
	 */
	public PluginFileAppender(Layout layout,IPath stateLocation, String file) throws IOException {
		super();
		setLayout(layout);
		setStateLocation(stateLocation);
		setFile(file);
		activateOptions();
	}

	/**
	 * Sets the state location. If activateOptions call is pending, translate the file name
	 * and call activateOptions
	 * @param stateLocation IPath containing the plug-in state location
	 */
	void setStateLocation(IPath stateLocation) {
		this.stateLocation = stateLocation;
		if (this.stateLocation != null && this.activateOptionsPending) {
			this.activateOptionsPending = false;
			setFile(getFile());
			activateOptions();
		}
	}

	/**
	 * Sets the file name.Translate it before setting.
	 * @param file file name
	 */
	public void setFile(String file) {
		super.setFile(getTranslatedFileName(file));
	}

	/**
	 * Set file options and opens it, leaving ready to write.
	 * @param file file name
	 * @param append true if file is to be appended
	 * @param bufferedIO true if file is to buffered
	 * @param bufferSize buffer size
	 * @throws IOException - IO Error happend or the state location was not set
	 */
	public void setFile(String fileName,boolean append,boolean bufferedIO,int bufferSize) throws IOException {
		if (this.stateLocation == null)
			throw new IOException(ConsoleMessages.PluginFileAppender_missing_plugin_state_location);

		fileName = (this.translatePath) ?  getTranslatedFileName(fileName) : fileName;
		super.setFile(fileName,append,bufferedIO,bufferSize);
	}

	/**
	 * Finishes instance initialization. If state location was not set, set activate as
	 * pending and does nothing.
	 */
	public void activateOptions() {
		if (this.stateLocation == null) {
			this.activateOptionsPending = true;
			return;
		}

		// base class will call setFile, don't translate the name
		// because it was already translated
		this.translatePath = false;
		super.activateOptions();
		this.translatePath = true;
	}

	/**
	 * Any path part of a file is removed and the state location is added to the name
	 * to form a new path. If there is not state location, returns the name unmodified.
	 * @param file file name
	 * @return translated file name
	 */
	private String getTranslatedFileName(String file) {

		if (this.stateLocation == null || file == null)
			return file;

		file = file.trim();
		if (file.length() == 0)
			return file;

		int index = file.lastIndexOf('/');
		if (index == -1)
			index = file.lastIndexOf('\\');

		if (index != -1)
			file = file.substring(index + 1);

		IPath newPath = this.stateLocation.append(file);
		return newPath.toString();
	}

	public void append(LoggingEvent event) {
		super.append( event );
	}
}