Log4J: Comment rediriger un OutputStream ou un Writer vers le (s) écrivain (s) de l'enregistreur?
J'ai une méthode qui s'exécute de manière asynchrone après le démarrage, en utilisant OutputStream ou Writer en tant que paramètre.
Il agit comme un adaptateur d'enregistrement pour OutputStream ou Writer ( c'est une API tierce que je ne peux pas changer ).
Comment pourrais-je passer OutputStream ou Writer interne de Log4J à cette méthode?
... parce que Log4J avalait System.out et System.err, je les utilisais auparavant.
Ma suggestion est, pourquoi ne pas vous écrivez votre OutputStream alors?! J'étais sur le point d'en écrire un pour vous, mais j'ai trouvé ce bon exemple sur le net, allez le voir!
/*
* Jacareto Copyright (c) 2002-2005
* Applied Computer Science Research Group, Darmstadt University of
* Technology, Institute of Mathematics & Computer Science,
* Ludwigsburg University of Education, and Computer Based
* Learning Research Group, Aachen University. All rights reserved.
*
* Jacareto 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 2 of the License, or (at your option) any later version.
*
* Jacareto 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 Jacareto; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
package jacareto.toolkit.log4j;
import org.Apache.log4j.Level;
import org.Apache.log4j.Logger;
import Java.io.OutputStream;
/**
* This class logs all bytes written to it as output stream with a specified logging level.
*
* @author <a href="mailto:[email protected]">Christian Spannagel</a>
* @version 1.0
*/
public class LogOutputStream extends OutputStream {
/** The logger where to log the written bytes. */
private Logger logger;
/** The level. */
private Level level;
/** The internal memory for the written bytes. */
private String mem;
/**
* Creates a new log output stream which logs bytes to the specified logger with the specified
* level.
*
* @param logger the logger where to log the written bytes
* @param level the level
*/
public LogOutputStream (Logger logger, Level level) {
setLogger (logger);
setLevel (level);
mem = "";
}
/**
* Sets the logger where to log the bytes.
*
* @param logger the logger
*/
public void setLogger (Logger logger) {
this.logger = logger;
}
/**
* Returns the logger.
*
* @return DOCUMENT ME!
*/
public Logger getLogger () {
return logger;
}
/**
* Sets the logging level.
*
* @param level DOCUMENT ME!
*/
public void setLevel (Level level) {
this.level = level;
}
/**
* Returns the logging level.
*
* @return DOCUMENT ME!
*/
public Level getLevel () {
return level;
}
/**
* Writes a byte to the output stream. This method flushes automatically at the end of a line.
*
* @param b DOCUMENT ME!
*/
public void write (int b) {
byte[] bytes = new byte[1];
bytes[0] = (byte) (b & 0xff);
mem = mem + new String(bytes);
if (mem.endsWith ("\n")) {
mem = mem.substring (0, mem.length () - 1);
flush ();
}
}
/**
* Flushes the output stream.
*/
public void flush () {
logger.log (level, mem);
mem = "";
}
}
Source: http://sysgears.com/articles/how-to-redirect-stdout-and-stderr-writing-to-a-log4j-appender/
Blockquote
Log4j ne permet pas de récupérer les messages stdout et stderr. Toutefois, si vous utilisez des composants tiers et devez consigner les messages qu'ils vident dans les flux, vous pouvez faire un petit truc et implémenter un flux de sortie personnalisé prenant en charge la journalisation.
Cela a déjà été fait par Jim Moore (voir le code source LoggingOutputStream dans log4j). Le seul problème est que LoggingOutputStream de JimMoore nécessite org.Apache.log4j.Category et org.Apache.log4j.Priority, qui sont maintenant partiellement obsolètes.
Voici LoggingOutputStream modifié qui évite les méthodes obsolètes:
public class LoggingOutputStream extends OutputStream {
/**
* Default number of bytes in the buffer.
*/
private static final int DEFAULT_BUFFER_LENGTH = 2048;
/**
* Indicates stream state.
*/
private boolean hasBeenClosed = false;
/**
* Internal buffer where data is stored.
*/
private byte[] buf;
/**
* The number of valid bytes in the buffer.
*/
private int count;
/**
* Remembers the size of the buffer.
*/
private int curBufLength;
/**
* The logger to write to.
*/
private Logger log;
/**
* The log level.
*/
private Level level;
/**
* Creates the Logging instance to flush to the given logger.
*
* @param log the Logger to write to
* @param level the log level
* @throws IllegalArgumentException in case if one of arguments
* is null.
*/
public LoggingOutputStream(final Logger log,
final Level level)
throws IllegalArgumentException {
if (log == null || level == null) {
throw new IllegalArgumentException(
"Logger or log level must be not null");
}
this.log = log;
this.level = level;
curBufLength = DEFAULT_BUFFER_LENGTH;
buf = new byte[curBufLength];
count = 0;
}
/**
* Writes the specified byte to this output stream.
*
* @param b the byte to write
* @throws IOException if an I/O error occurs.
*/
public void write(final int b) throws IOException {
if (hasBeenClosed) {
throw new IOException("The stream has been closed.");
}
// don't log nulls
if (b == 0) {
return;
}
// would this be writing past the buffer?
if (count == curBufLength) {
// grow the buffer
final int newBufLength = curBufLength +
DEFAULT_BUFFER_LENGTH;
final byte[] newBuf = new byte[newBufLength];
System.arraycopy(buf, 0, newBuf, 0, curBufLength);
buf = newBuf;
curBufLength = newBufLength;
}
buf[count] = (byte) b;
count++;
}
/**
* Flushes this output stream and forces any buffered output
* bytes to be written out.
*/
public void flush() {
if (count == 0) {
return;
}
final byte[] bytes = new byte[count];
System.arraycopy(buf, 0, bytes, 0, count);
String str = new String(bytes);
log.log(level, str);
count = 0;
}
/**
* Closes this output stream and releases any system resources
* associated with this stream.
*/
public void close() {
flush();
hasBeenClosed = true;
}
}
Vous pouvez maintenant intercepter les messages envoyés à stderr ou stdout de la manière suivante:
System.setErr(new PrintStream(new LoggingOutputStream(
Logger.getLogger("outLog"), Level.ERROR)));
La configuration log4j.properties:
log4j.logger.outLog=error, out_log
log4j.appender.out_log=org.Apache.log4j.RollingFileAppender
log4j.appender.out_log.file=/logs/error.log
log4j.appender.out_log.MaxFileSize=10MB
log4j.appender.out_log.threshold=error
Dmitriy Pavlenko, SysGears
Blockquote
Vous pouvez utiliser Log4j IOStreams
Le composant IOStreams est une extension de l'API Log4j qui fournit de nombreuses classes de Java.io qui peuvent écrire dans un enregistreur lors de l'écriture sur un autre OutputStream ou Writer, ou le contenu lu par InputStream ou Reader peut être mis sous écoute par un enregistreur.
Vous pouvez créer un OutputStream de cette façon:
OutputStream outputStream = IoBuilder
.forLogger(logger)
.buildOutputStream();
Vous trouverez ci-dessous un exemple avec Appium, le démarrant par programme et contrôlant son journal avec log4j.
final Logger logger = LogManager.getLogger(getClass());
cap = new DesiredCapabilities();
cap.setCapability("noReset", "false");
//Build the Appium service
builder = new AppiumServiceBuilder();
builder.withIPAddress("127.0.0.1");
builder.usingPort(4723);
builder.withCapabilities(cap);
builder.withArgument(GeneralServerFlag.SESSION_OVERRIDE);
builder.withArgument(GeneralServerFlag.LOG_LEVEL,"debug");
//Start the server with the builder
service = AppiumDriverLocalService.buildService(builder);
OutputStream outputStream = IoBuilder
.forLogger(logger)
.buildOutputStream();
service.addOutPutStream(outputStream);
service.start();
J'espère que cela t'aides!!!
Depuis l'exemple précédent d'un écrivain qui a dirigé vers Log4J est mort: http://www.opensource.Apple.com/source/JBoss/JBoss-737/jboss-all/common/src/main/org/jboss /logging/util/LoggerWriter.Java