/**
* Copyright (C) 2005 - 2009 Eric Van Dewoestine
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.eclim.logging.log4j;
import java.io.IOException;
import java.io.OutputStream;
import java.io.Writer;
/**
* Extension to log4j's ConsoleAppender that holds onto the configured stream
* instead of continuously grabbing it, preventing calls to System.setOut() or
* System.setErr() from resulting in undesired behavior.
*
* @author Eric Van Dewoestine
*/
public class ConsoleAppender
extends org.apache.log4j.ConsoleAppender
{
private boolean writerSet;
/**
* Prepares the appender for use.
*/
public void activateOptions()
{
if(getTarget().equals(SYSTEM_ERR)) {
setWriter(createWriter(new SystemStream(System.err)));
} else {
setWriter(createWriter(new SystemStream(System.out)));
}
super.activateOptions();
}
/**
* {@inheritDoc}
*/
public synchronized void setWriter(Writer writer)
{
if(!writerSet){
super.setWriter(writer);
writerSet = true;
}
}
/**
* An implementation of OutputStream that redirects to the
* stream supplied at construction.
*/
private static class SystemStream
extends OutputStream
{
private OutputStream out;
/**
* Wraps the supplied stream, System.out or System.err.
*
* @param out The stream to wrap.
*/
public SystemStream (OutputStream out)
{
this.out = out;
}
/**
* {@inheritDoc}
*/
public void close()
{
// don't close System.out or System.err
}
/**
* {@inheritDoc}
*/
public void flush()
throws IOException
{
out.flush();
}
/**
* {@inheritDoc}
*/
public void write(final byte[] bytes)
throws IOException
{
out.write(bytes);
}
/**
* {@inheritDoc}
*/
public void write(final byte[] bytes, final int offset, final int length)
throws IOException
{
out.write(bytes, offset, length);
}
/**
* {@inheritDoc}
*/
public void write(final int bytes)
throws IOException
{
out.write(bytes);
}
}
}