/*
* $Header: /home/cvs/jakarta-tomcat/proposals/catalina/src/share/org/apache/tomcat/logger/LoggerBase.java,v 1.2 2000/01/29 07:46:34 craigmcc Exp $
* $Revision: 1.2 $
* $Date: 2000/01/29 07:46:34 $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
* [Additional notices, if required by prior licensing conditions]
*
*/
package org.apache.tomcat.logger;
import java.beans.PropertyChangeSupport;
import java.beans.PropertyChangeListener;
import java.io.CharArrayWriter;
import java.io.PrintWriter;
import org.apache.tomcat.Container;
import org.apache.tomcat.Logger;
/**
* Convenience base class for <b>Logger</b> implementations. The only
* method that must be implemented is <code>log(String msg)</code>, plus
* any property setting and lifecycle methods required for configuration.
*
* @author Craig R. McClanahan
* @version $Revision: 1.2 $ $Date: 2000/01/29 07:46:34 $
*/
abstract class LoggerBase
implements Logger {
// ----------------------------------------------------- Instance Variables
/**
* The Container with which this Logger has been associated.
*/
protected Container container = null;
/**
* The descriptive information about this implementation.
*/
protected static final String info =
"org.apache.tomcat.logger.LoggerBase/1.0";
/**
* The property change support for this component.
*/
protected PropertyChangeSupport support = new PropertyChangeSupport(this);
// ------------------------------------------------------------- Properties
/**
* Return the Container with which this Logger has been associated.
*/
public Container getContainer() {
return (container);
}
/**
* Set the Container with which this Logger has been associated.
*
* @param container The associated Container
*/
public void setContainer(Container container) {
Container oldContainer = this.container;
this.container = container;
support.firePropertyChange("container", oldContainer, this.container);
}
/**
* Return descriptive information about this Logger implementation and
* the corresponding version number, in the format
* <code><description>/<version></code>.
*/
public String getInfo() {
return (info);
}
// --------------------------------------------------------- Public Methods
/**
* Add a property change listener to this component.
*
* @param listener The listener to add
*/
public void addPropertyChangeListener(PropertyChangeListener listener) {
support.addPropertyChangeListener(listener);
}
/**
* Writes the specified message to a servlet log file, usually an event
* log. The name and type of the servlet log is specific to the
* servlet container.
*
* @param msg A <code>String</code> specifying the message to be written
* to the log file
*/
public abstract void log(String msg);
/**
* Writes the specified exception, and message, to a servlet log file.
* The implementation of this method should call
* <code>log(msg, exception)</code> instead. This method is deprecated
* in the ServletContext interface, but not deprecated here to avoid
* many useless compiler warnings.
*
* @param exception An <code>Exception</code> to be reported
* @param msg The associated message string
*/
public void log(Exception exception, String msg) {
log(msg, exception);
}
/**
* Writes an explanatory message and a stack trace for a given
* <code>Throwable</code> exception to the servlet log file. The name
* and type of the servlet log file is specific to the servlet container,
* usually an event log.
*
* @param msg A <code>String</code> that describes the error or
* exception
* @param throwable The <code>Throwable</code> error or exception
*/
public void log(String msg, Throwable throwable) {
CharArrayWriter buf = new CharArrayWriter();
PrintWriter writer = new PrintWriter(buf);
writer.print(msg);
throwable.printStackTrace(writer);
log(buf.toString());
}
/**
* Remove a property change listener from this component.
*
* @param listener The listener to remove
*/
public void removePropertyChangeListener(PropertyChangeListener listener) {
support.removePropertyChangeListener(listener);
}
}