/*
* 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.
*/
package org.apache.tomcat.util;
import java.io.Serial;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* Wraps a list of throwables as a single throwable. This is intended to be used when multiple actions are taken where
* each may throw an exception but all actions are taken before any errors are reported.
* <p>
* This class is <b>NOT</b> threadsafe.
*/
public class MultiThrowable extends Throwable {
@Serial
private static final long serialVersionUID = 1L;
private final List<Throwable> throwables = new ArrayList<>();
/**
* Add a throwable to the list of wrapped throwables.
*
* @param t The throwable to add
*/
public void add(Throwable t) {
throwables.add(t);
}
/**
* @return A read-only list of the wrapped throwables.
*/
public List<Throwable> getThrowables() {
return Collections.unmodifiableList(throwables);
}
/**
* @return {@code null} if there are no wrapped throwables, the Throwable if there is a single wrapped throwable or
* the current instance of there are multiple wrapped throwables
*/
public Throwable getThrowable() {
if (size() == 0) {
return null;
} else if (size() == 1) {
return throwables.get(0);
} else {
return this;
}
}
/**
* @return The number of throwables currently wrapped by this instance.
*/
public int size() {
return throwables.size();
}
/**
* Overrides the default implementation to provide a concatenation of the messages associated with each of the
* wrapped throwables. Note that the format of the returned String is not guaranteed to be fixed and may change in a
* future release.
*/
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append(super.toString());
sb.append(": ");
sb.append(size());
sb.append(" wrapped Throwables: ");
for (Throwable t : throwables) {
sb.append('[');
sb.append(t.getMessage());
sb.append(']');
}
return sb.toString();
}
}