PluginLogListener.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.ILogListener;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.eclipse.core.runtime.ILog;

/**
 * PluginLogListener This class is responsible for adding itself to the plug-in logging framework and translating plug-in log requests to Logger events.
 * 
 * @author Manoel Marques
 */
class PluginLogListener implements ILogListener {

    private ILog log;

    private Logger logger;

    /**
     * Creates a new PluginLogListener. Saves the plug-in log and logger instance. Adds itself to the plug-in log.
     * 
     * @param plugin the plug-in object
     * @param logger logger instance
     */
    PluginLogListener(ILog log, Logger logger) {
        this.log = log;
        this.logger = logger;
        log.addLogListener(this);
    }

    /**
     * Removes itself from the plug-in log, reset instance variables.
     */
    void dispose() {
        if (this.log != null) {
            this.log.removeLogListener(this);
            this.log = null;
            this.logger = null;
        }
    }

    /**
     * Log event happened. Translates status instance to Logger level and message. Status.ERROR - Level.ERROR Status.WARNING - Level.WARN Status.INFO - Level.INFO Status.CANCEL - Level.FATAL default - Level.DEBUG
     * 
     * @param status Log Status
     * @param plugin plug-in id
     */
    public void logging(IStatus status, String plugin) {
        if (null == this.logger || null == status)
            return;

        int severity = status.getSeverity();
        Level level = determineLevel(severity);

        plugin = formatText(plugin);
        String statusPlugin = formatText(status.getPlugin());
        String statusMessage = formatText(status.getMessage());
        StringBuffer message = new StringBuffer();
        if (plugin != null) {
            message.append(plugin);
            message.append(" - ");
        }
        if (statusPlugin != null && (plugin == null || !statusPlugin.equals(plugin))) {
            message.append(statusPlugin);
            message.append(" - ");
        }
        message.append(status.getCode());
        if (statusMessage != null) {
            message.append(" - ");
            message.append(statusMessage);
        }
        this.logger.log(level, message.toString(), status.getException());
    }
    private Level determineLevel(int severity){
        Level level = Level.DEBUG;
        if (severity == Status.ERROR)
            level = Level.ERROR;
        else if (severity == Status.WARNING)
            level = Level.WARN;
        else if (severity == Status.INFO)
            level = Level.INFO;
        else if (severity == Status.CANCEL)
            level = Level.FATAL;
        return level;
    }
    
    private static String formatText(String text) {
        if (text != null) {
            text = text.trim();
            if (text.length() == 0)
                return null;
        }
        return text;
    }
}