/*
 * $Id$
 *
 * 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.tiles.definition;

import org.apache.tiles.TilesException;

/**
 * Exception thrown when an error occurs while the impl tries to
 * create a new instance mapper.
 *
 * @version $Rev$ $Date$
 */
public class DefinitionsFactoryException extends TilesException {
    /**
     * Constructor.
     */
    public DefinitionsFactoryException() {
        super();
        this.exception = null;
    }

    /**
     * Constructor.
     *
     * @param message The error or warning message.
     */
    public DefinitionsFactoryException(String message) {
        super(message);
        this.exception = null;
    }


    /**
     * Create a new <code>DefinitionsFactoryException</code> wrapping an existing exception.
     * <p/>
     * <p>The existing exception will be embedded in the new
     * one and its message will become the default message for
     * the DefinitionsFactoryException.</p>
     *
     * @param e The exception to be wrapped.
     */
    public DefinitionsFactoryException(Exception e) {
        super();
        this.exception = e;
    }


    /**
     * Create a new <code>DefinitionsFactoryException</code> from an existing exception.
     * <p/>
     * <p>The existing exception will be embedded in the new
     * one, but the new exception will have its own message.</p>
     *
     * @param message The detail message.
     * @param e       The exception to be wrapped.
     */
    public DefinitionsFactoryException(String message, Exception e) {
        super(message);
        this.exception = e;
    }


    /**
     * Return a detail message for this exception.
     * <p/>
     * <p>If there is a embedded exception, and if the DefinitionsFactoryException
     * has no detail message of its own, this method will return
     * the detail message from the embedded exception.</p>
     *
     * @return The error or warning message.
     */
    public String getMessage() {
        String message = super.getMessage();

        if (message == null && exception != null) {
            return exception.getMessage();
        } else {
            return message;
        }
    }


    /**
     * Return the embedded exception, if any.
     *
     * @return The embedded exception, or <code>null</code> if there is none.
     */
    public Exception getException() {
        return exception;
    }

    //////////////////////////////////////////////////////////////////////
    // Internal state.
    //////////////////////////////////////////////////////////////////////


    /**
     * Any "wrapped" exception will be exposed when this is serialized.
     *
     * @serial
     */
    private Exception exception;
}