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Apache FOP (Formatting Objects Processor) is the world's first print formatter driven by XSL formatting objects (XSL-FO) and the world's first output independent formatter. It is a Java application that reads a formatting object (FO) tree and renders the resulting pages to a specified output. Output formats currently supported include PDF, PCL, PS, AFP, TIFF, PNG, SVG, XML (area tree representation), Print, AWT and TXT. The primary output target is PDF.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
/* $Id: LoggingEventListener.java 1301445 2012-03-16 11:44:09Z mehdi $ */
package org.apache.fop.events;
import java.util.HashSet;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.fop.events.model.EventSeverity;
/**
* EventListener implementation that redirects events to Commons Logging. The events are
* converted to localized messages.
*/
public class LoggingEventListener implements EventListener {
/** Default logger instance */
private static Log defaultLog = LogFactory.getLog(LoggingEventListener.class);
private Log log;
private boolean skipFatal;
private final Set loggedMessages = new HashSet();
/**
* Creates an instance logging to the default log category of this class.
*/
public LoggingEventListener() {
this(defaultLog);
}
/**
* Creates an instance logging to a given logger. Events with fatal severity level will be
* skipped.
* @param log the target logger
*/
public LoggingEventListener(Log log) {
this(log, true);
}
/**
* Creates an instance logging to a given logger.
* @param log the target logger
* @param skipFatal true if events with fatal severity level should be skipped (i.e. not logged)
*/
public LoggingEventListener(Log log, boolean skipFatal) {
this.log = log;
this.skipFatal = skipFatal;
}
/**
* Returns the target logger for this instance.
* @return the target logger
*/
public Log getLog() {
return this.log;
}
/** {@inheritDoc} */
public void processEvent(Event event) {
String msg = EventFormatter.format(event);
EventSeverity severity = event.getSeverity();
if (severity == EventSeverity.INFO) {
log.info(msg);
} else if (severity == EventSeverity.WARN) {
// we want to prevent logging of duplicate messages in situations where they are likely
// to occur; for instance, warning related to layout do not repeat (since line number
// will be different) and as such we do not try to filter them here; on the other hand,
// font related warnings are very likely to repeat and we try to filter them out here;
// the same may happen with missing images (but not implemented yet).
String eventGroupID = event.getEventGroupID();
if (eventGroupID.equals("org.apache.fop.fonts.FontEventProducer")) {
if (!loggedMessages.contains(msg)) {
loggedMessages.add(msg);
log.warn(msg);
}
} else {
log.warn(msg);
}
} else if (severity == EventSeverity.ERROR) {
if (event.getParam("e") != null) {
log.error(msg, (Throwable)event.getParam("e"));
} else {
log.error(msg);
}
} else if (severity == EventSeverity.FATAL) {
if (!skipFatal) {
if (event.getParam("e") != null) {
log.fatal(msg, (Throwable)event.getParam("e"));
} else {
log.fatal(msg);
}
}
} else {
assert false;
}
}
}