| /* |
| * Copyright 2011 Google Inc. |
| * |
| * Licensed 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. |
| */ |
| package com.google.web.bindery.event.shared; |
| |
| import java.util.Collections; |
| import java.util.Set; |
| |
| /** |
| * A {@link RuntimeException} that collects a {@link Set} of child |
| * {@link Throwable}s together. Typically thrown after a loop, with all of the |
| * exceptions thrown during that loop, but delayed so that the loop finishes |
| * executing. |
| */ |
| public class UmbrellaException extends RuntimeException { |
| |
| // Visible for testing |
| static final String MULTIPLE = " exceptions caught: "; |
| |
| // Visible for testing |
| static final String ONE = "Exception caught: "; |
| |
| protected static Throwable makeCause(Set<Throwable> causes) { |
| return causes.isEmpty() ? null : causes.iterator().next(); |
| } |
| |
| protected static String makeMessage(Set<Throwable> causes) { |
| int count = causes.size(); |
| if (count == 0) { |
| return null; |
| } |
| |
| StringBuilder b = new StringBuilder(count == 1 ? ONE : count + MULTIPLE); |
| boolean first = true; |
| for (Throwable t : causes) { |
| if (first) { |
| first = false; |
| } else { |
| b.append("; "); |
| } |
| b.append(t.getMessage()); |
| } |
| |
| return b.toString(); |
| } |
| |
| /** |
| * The causes of the exception. |
| */ |
| private Set<Throwable> causes; |
| |
| public UmbrellaException(Set<Throwable> causes) { |
| super(makeMessage(causes), makeCause(causes)); |
| this.causes = causes; |
| int i = 0; |
| for (Throwable cause : causes) { |
| if (i++ == 0) { |
| // First one already added as cause. |
| continue; |
| } |
| addSuppressed(cause); |
| } |
| } |
| |
| /** |
| * Required for GWT RPC serialization. |
| */ |
| protected UmbrellaException() { |
| // Can't delegate to the other constructor or GWT RPC gets cranky |
| super(MULTIPLE); |
| this.causes = Collections.<Throwable> emptySet(); |
| } |
| |
| /** |
| * Get the set of exceptions that caused the failure. |
| * |
| * @return the set of causes |
| */ |
| public Set<Throwable> getCauses() { |
| return causes; |
| } |
| } |