Source code

001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.util;
020
021import org.apache.reef.annotations.audience.Private;
022import org.apache.reef.wake.EventHandler;
023
024/**
025 * An ExceptionHandler that wraps another one, but catches all exceptions thrown by that one and forwards them
026 * to an ExceptionHandler.
027 *
028 * @param <T> the event type handled
029 */
030@Private
031public final class ExceptionHandlingEventHandler<T> implements EventHandler<T> {
032
033  private final EventHandler<T> wrapped;
034  private final EventHandler<Throwable> exceptionHandler;
035
036  public ExceptionHandlingEventHandler(final EventHandler<T> wrapped,
037                                       final EventHandler<Throwable> exceptionHandler) {
038    this.wrapped = wrapped;
039    this.exceptionHandler = exceptionHandler;
040  }
041
042  @Override
043  @SuppressWarnings("checkstyle:illegalcatch")
044  public void onNext(final T t) {
045    try {
046      this.wrapped.onNext(t);
047    } catch (final Throwable throwable) {
048      this.exceptionHandler.onNext(throwable);
049    }
050  }
051}