/*
* 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: EventExceptionManager.java 1761021 2016-09-16 11:40:57Z ssteiner $ */
package org.apache.fop.events;
import java.util.Iterator;
import java.util.Map;
import org.apache.xmlgraphics.util.Service;
This class is responsible for converting events into exceptions.
/**
* This class is responsible for converting events into exceptions.
*/
public final class EventExceptionManager {
private EventExceptionManager() {
}
private static final Map<String, ExceptionFactory> EXCEPTION_FACTORIES
= new java.util.HashMap<String, ExceptionFactory>();
static {
Iterator<Object> iter;
iter = Service.providers(ExceptionFactory.class);
while (iter.hasNext()) {
ExceptionFactory factory = (ExceptionFactory)iter.next();
EXCEPTION_FACTORIES.put(factory.getExceptionClass().getName(), factory);
}
}
Converts an event into an exception and throws that. If the exception class is null, a RuntimeException
will be thrown. Params: - event – the event to be converted
- exceptionClass – the exception class to be thrown
Throws: - Throwable – this happens always
/**
* Converts an event into an exception and throws that. If the exception class is null,
* a {@link RuntimeException} will be thrown.
* @param event the event to be converted
* @param exceptionClass the exception class to be thrown
* @throws Throwable this happens always
*/
public static void throwException(Event event, String exceptionClass) throws Throwable {
if (exceptionClass != null) {
ExceptionFactory factory = EXCEPTION_FACTORIES.get(exceptionClass);
if (factory != null) {
throw factory.createException(event);
} else {
throw new IllegalArgumentException(
"No such ExceptionFactory available: " + exceptionClass);
}
} else {
String msg = EventFormatter.format(event);
//Get original exception as cause if it is given as one of the parameters
Throwable t = null;
for (Object o : event.getParams().values()) {
if (o instanceof Throwable) {
t = (Throwable) o;
break;
}
}
if (t != null) {
throw new RuntimeException(msg, t);
} else {
throw new RuntimeException(msg);
}
}
}
This interface is implementation by exception factories that can create exceptions from
events.
/**
* This interface is implementation by exception factories that can create exceptions from
* events.
*/
public interface ExceptionFactory {
Creates an exception from an event.
Params: - event – the event
Returns: the newly created exception
/**
* Creates an exception from an event.
* @param event the event
* @return the newly created exception
*/
Throwable createException(Event event);
Returns the Exception
class created by this factory. Returns: the exception class
/**
* Returns the {@link Exception} class created by this factory.
* @return the exception class
*/
Class<? extends Exception> getExceptionClass();
}
}