/*
 * Copyright 2012 LinkedIn, 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.linkedin.parseq;

import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;


/**
 * An exception representing multiple exceptions.  Useful for example to deliver multiple
 * exceptions to a callback interface which only accepts a single Exception.
 * @author Steven Ihde
 */

public class MultiException extends Exception {
  private static final long serialVersionUID = 1L;

  private final Collection<? extends Throwable> _causes;

  public MultiException(String message, Collection<? extends Throwable> causes) {
    super(message);
    _causes = (causes == null ? Collections.<Throwable> emptyList() : causes);

    // Let the first exception be the cause so at least something shows up in the stack
    // trace; we can't just override printStackTrace() because OUR printStackTrace() is
    // not invoked when this exception is the cause of another.
    Iterator<? extends Throwable> i = _causes.iterator();
    if (i.hasNext()) {
      initCause(i.next());
    }
  }

  public MultiException(Collection<? extends Throwable> causes) {
    this(null, causes);
  }

  public Collection<? extends Throwable> getCauses() {
    return _causes;
  }

  @Override
  public String toString() {
    // MultiException: Xyz failed (multiple causes follow; only first is shown in stack trace): [java.lang.FooException: bar, java.lang.BazException: quux]
    return super.toString() + " (multiple causes follow; only first is shown in stack trace): " + _causes;
  }
}