com.google.web.bindery.event.shared.UmbrellaException Maven / Gradle / Ivy
/*
* 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.Iterator;
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 causes) {
Iterator iterator = causes.iterator();
if (!iterator.hasNext()) {
return null;
}
return iterator.next();
}
protected static String makeMessage(Set 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 causes;
public UmbrellaException(Set causes) {
super(makeMessage(causes), makeCause(causes));
this.causes = causes;
}
/**
* Required for GWT RPC serialization.
*/
protected UmbrellaException() {
// Can't delegate to the other constructor or GWT RPC gets cranky
super(MULTIPLE);
this.causes = Collections. emptySet();
}
/**
* Get the set of exceptions that caused the failure.
*
* @return the set of causes
*/
public Set getCauses() {
return causes;
}
}