PluginLogAppender.java

/*******************************************************************************
 * Copyright (c) 2008 Pierre-Antoine Grégoire.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Pierre-Antoine Grégoire - initial API and implementation
 *******************************************************************************/
package org.org.eclipse.core.utils.platform.tools.logging;

import org.eclipse.core.runtime.ILog;
import org.eclipse.core.runtime.Status;
import org.apache.log4j.Level;
import org.apache.log4j.AppenderSkeleton;
import org.apache.log4j.spi.ErrorCode;
import org.apache.log4j.spi.LoggingEvent;
import org.apache.log4j.spi.ThrowableInformation;

/**
 * PluginLogAppender This class is a custom Log4J appender that sends Log4J events to the Eclipse plug-in log.
 * 
 * @author Manoel Marques
 */
public class PluginLogAppender extends AppenderSkeleton {

    private static ILog pluginLog;

    /**
     * Sets the Eclipse log instance
     * 
     * @param log plug-in log
     */
    public static void setLog(ILog pluginLog) {
        if (PluginLogAppender.pluginLog == null) {
            PluginLogAppender.pluginLog = pluginLog;
        }
    }

    /**
     * Log event happened. Translates level to status instance codes: level > Level.ERROR - Status.ERROR level > Level.WARN - Status.WARNING level > Level.DEBUG - Status.INFO default - Status.OK
     * 
     * @param event LoggingEvent instance
     */
    public void append(LoggingEvent event) {

        if (this.layout == null) {
            this.errorHandler.error("Missing layout for appender " + this.name, null, ErrorCode.MISSING_LAYOUT);
            return;
        }

        String text = this.layout.format(event);

        Throwable thrown = null;
        if (this.layout.ignoresThrowable()) {
            ThrowableInformation info = event.getThrowableInformation();
            if (info != null)
                thrown = info.getThrowable();
        }

        Level level = event.getLevel();
        int severity = Status.OK;

        if (level.toInt() >= Level.ERROR_INT)
            severity = Status.ERROR;
        else if (level.toInt() >= Level.WARN_INT)
            severity = Status.WARNING;
        else if (level.toInt() >= Level.DEBUG_INT)
            severity = Status.INFO;

        pluginLog.log(new Status(severity, pluginLog.getBundle().getSymbolicName(), level.toInt(), text, thrown));
    }

    /**
     * Closes this appender
     */
    public void close() {
        this.closed = true;
    }

    /**
     * Checks if this appender requires layout
     * 
     * @return true if layout is required.
     */
    public boolean requiresLayout() {
        return true;
    }
}