/*
* $Id$
*
* Copyright (C) 2003-2014 JNode.org
*
* This library 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 library 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 library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.log4j.config;
import java.io.Writer;
import javax.naming.NameNotFoundException;
import org.apache.log4j.Layout;
import org.apache.log4j.WriterAppender;
import org.jnode.driver.console.ConsoleManager;
import org.jnode.driver.console.TextConsole;
import org.jnode.naming.InitialNaming;
/**
* Custom Log4j appender class for appending to JNode consoles. This appender
* avoids the unnecessary Writer to Stream to Writer wrappering that goes on
* if we use the standard Log4j ConsoleAppender. (JNode's consoles are natively
* character oriented rather than byte oriented.)
*
* @author Ewout Prangsma (epr@users.sourceforge.net)
* @author crawley@jnode.org
*/
public class VirtualConsoleAppender extends WriterAppender {
private static ConsoleManager mgr;
private Writer writer;
/**
* Create an appender for a named JNode console.
* @param layout the appender's initial log message layout.
* @param name the target console name.
* @param toErr if <code>true</code> output to the console's 'err' stream,
* otherwise to it's 'out' stream.
*/
public VirtualConsoleAppender(Layout layout, String name, boolean toErr) {
super();
this.layout = layout;
TextConsole console = getNamedConsole(name);
this.writer = toErr ? console.getErr() : console.getOut();
super.setWriter(this.writer);
}
private static synchronized TextConsole getNamedConsole(String name) {
if (mgr == null) {
try {
mgr = InitialNaming.lookup(ConsoleManager.NAME);
} catch (NameNotFoundException ex) {
return null;
}
}
try {
TextConsole res = (TextConsole) mgr.getConsole(name);
if (res == null) {
throw new IllegalArgumentException("Unknown console: '" + name + '\'');
}
return res;
} catch (ClassCastException ex) {
throw new IllegalArgumentException("Console '" + name + "' is not a TextConsole");
}
}
/**
* Create an appender for a JNode console supplied as an argument.
* @param layout the appender's initial log message layout.
* @param console the target console.
* @param toErr if <code>true</code> output to the console's 'err' stream,
* otherwise to it's 'out' stream.
*/
public VirtualConsoleAppender(Layout layout, TextConsole console, boolean toErr) {
super();
this.layout = layout;
this.writer = toErr ? console.getErr() : console.getOut();
super.setWriter(this.writer);
}
@Override
protected void closeWriter() {
// Ignore the close request. We don't own the writer.
}
@Override
public void activateOptions() {
super.setWriter(writer);
}
@Override
public synchronized void setWriter(Writer writer) {
if (writer != this.writer) {
throw new IllegalArgumentException("cannot change the writer");
}
super.setWriter(writer);
}
}