src/plugins/logger/src/com/motorola/studio/android/logger/Logger.java

/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*      http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.motorola.studio.android.logger;

import java.util.HashMap;

import org.apache.log4j.Level;

import com.motorola.studio.android.logger.internal.EclipseEnvironmentManager;
import com.motorola.studio.android.logger.internal.EnvironmentManager;

/**
 * Logger provides a logging facility to the <b>MOTODEV Studio</b> based
 * applications such as Studios and RCP applications. </p> <b>Note:</b> The logs
 * will be saved on the plug-in state area for this plug-in.
 */
public class Logger
{

    // Class Constants --------------------------------------------------------

    /**
     * This static block loads the log4j configuration file and resolves the
     * path to save the logger log file.
     */
    static
    {
        /* Logging Environment Information */
        EnvironmentManager envManager = new EclipseEnvironmentManager();
        envManager.logEnvironment();
    }

    // Private Variables
    // --------------------------------------------------------

    /*
     * This Map pools the Logger instances.
     */
    private static HashMap<String, Logger> pool;

    /*
     * Log4j logger instance being wrapped.
     */
    private final org.apache.log4j.Logger logger;

    /**
     * Builds a logger associated to the specified name.
     * 
     * @param name The name of the logger.
     */
    private Logger(String name)
    {
        logger = org.apache.log4j.Logger.getLogger(name);
    }

    /**
     * Gets a logger named according to the value of the name parameter. If the
     * named logger already exists, then the existing instance will be returned.
     * Otherwise, a new instance is created.
     * 
     * @param name The name of the logger.
     * @return the logger associated to the specified name.
     */
    public static synchronized Logger getLogger(String name)
    {
        Logger logger = null;
        if (pool == null)
        {
            pool = new HashMap<String, Logger>();
        }

        if (pool.containsKey(name))
        {
            logger = pool.get(name);
        }
        else
        {
            logger = new Logger(name);
            pool.put(name, logger);
        }
        return logger;
    }

    /**
     * Logs the specified message with the specified level.
     * 
     * @param level The log level.
     * @param message The message to log.
     */
    public void log(int level, String message)
    {
        boolean key = true;
        if ((level == com.motorola.studio.android.logger.Level.OFF)
                || (level == com.motorola.studio.android.logger.Level.ALL))
        {
            key = false;
        }

        if (key)
        {
            logger.log(Level.toLevel(level), message);
        }
    }

    /**
     * Logs the specified message and an exception stack trace.
     * 
     * @param level The log level.
     * @param message The message to log.
     * @param exception Exception whose stack will be logged.
     */
    public void log(int level, String message, Throwable exception)
    {
        boolean key = true;
        if ((level == com.motorola.studio.android.logger.Level.OFF)
                || (level == com.motorola.studio.android.logger.Level.ALL))
        {
            key = false;
        }
        if (key)
        {
            logger.log(Level.toLevel(level), message, exception);
        }
    }

    /**
     * Log a message object with the DEBUG level.
     * 
     * @param message The message to log.
     */
    public void debug(String message)
    {
        debug(message, null);
    }

    /**
     * Log a message object with the DEBUG level.
     * 
     * @param message The message to log.
     * @param exception Exception whose stack will be logged.
     */
    public void debug(String message, Throwable exception)
    {
        if (null == exception)
        {
            logger.debug(message);
        }
        else
        {
            logger.debug(message, exception);
        }
    }

    /**
     * Log a message object with the INFO level.
     * 
     * @param message The message to log.
     */
    public void info(String message)
    {
        info(message, null);
    }

    /**
     * Log a message object with the INFO level.
     * 
     * @param message The message to log.
     * @param exception Exception whose stack will be logged.
     */
    public void info(String message, Throwable exception)
    {
        if (null == exception)
        {
            logger.info(message);
        }
        else
        {
            logger.info(message, exception);
        }
    }

    /**
     * Log a message object with the WARN level.
     * 
     * @param message The message to log.
     */
    public void warn(String message)
    {
        warn(message, null);
    }

    /**
     * Log a message object with the WARN level.
     * 
     * @param message The message to log.
     * @param exception Exception whose stack will be logged.
     */
    public void warn(String message, Throwable exception)
    {
        if (null == exception)
        {
            logger.warn(message);
        }
        else
        {
            logger.warn(message, exception);
        }
    }

    /**
     * Log a message object with the ERROR level.
     * 
     * @param message The message to log.
     */
    public void error(String message)
    {
        error(message, null);
    }

    /**
     * Log a message object with the ERROR level.
     * 
     * @param message The message to log.
     * @param exception Exception whose stack will be logged.
     */
    public void error(String message, Throwable exception)
    {
        if (null == exception)
        {
            logger.error(message);
        }
        else
        {
            logger.error(message, exception);
        }
    }

    /**
     * Log a message object with the FATAL level.
     * 
     * @param message The message to log.
     */
    public void fatal(String message)
    {
        fatal(message, null);
    }

    /**
     * Log a message object with the FATAL level.
     * 
     * @param message The message to log.
     * @param exception Exception whose stack will be logged.
     */
    public void fatal(String message, Throwable exception)
    {
        if (null == exception)
        {
            logger.fatal(message);
        }
        else
        {
            logger.fatal(message, exception);
        }
    }

    /**
     * Sets the Logger level to the specified value.
     * 
     * @param level One of the com.motorola.studio.platform.logger.Level
     *            constants.
     */
    public void setLevel(int level)
    {
        logger.setLevel(Level.toLevel(level));
    }
}