| /* |
| * 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. |
| */ |
| |
| /* $Id$ */ |
| |
| 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. |
| */ |
| public class EventExceptionManager { |
| |
| private static final Map EXCEPTION_FACTORIES = new java.util.HashMap(); |
| |
| static { |
| Iterator iter; |
| iter = Service.providers(ExceptionFactory.class, true); |
| 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 {@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 = (ExceptionFactory)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; |
| Iterator iter = event.getParams().values().iterator(); |
| while (iter.hasNext()) { |
| Object o = iter.next(); |
| 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. |
| */ |
| public interface ExceptionFactory { |
| |
| /** |
| * Creates an exception from an event. |
| * @param event the event |
| * @return the newly created exception |
| */ |
| Throwable createException(Event event); |
| |
| /** |
| * Returns the {@link Exception} class created by this factory. |
| * @return the exception class |
| */ |
| Class getExceptionClass(); |
| } |
| } |