001    /*
002     * Copyright (c) 2005 Stephen J. McConnell
003     *
004     * Licensed  under the  Apache License,  Version 2.0  (the "License");
005     * you may not use  this file  except in  compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     *   http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed  under the  License is distributed on an "AS IS" BASIS,
012     * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
013     * implied.
014     *
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    
019    package net.dpml.component;
020    
021    import java.io.IOException;
022    import java.net.URI;
023    
024    /**
025     * General exception thrown by a control.
026     *
027     * @author <a href="http://www.dpml.net">Digital Product Meta Library</a>
028     * @version 1.0.1
029     */
030    public class ControlException extends IOException  
031    {
032       /**
033        * Serial version identifier.
034        */
035        static final long serialVersionUID = 1L;
036    
037        private final URI m_uri;
038    
039       /**
040        * Creation of a new <tt>ControlException</tt>.
041        * @param uri the part controller uri
042        * @param message the exception message
043        */
044        public ControlException( URI uri, String message )
045        {
046            this( uri, message, null );
047        }
048    
049       /**
050        * Creation of a new <tt>ContextException</tt>.
051        * @param uri the part controller uri
052        * @param message the exception message
053        * @param cause the causal exception
054        */
055        public ControlException( URI uri, String message, Throwable cause )
056        {
057            super( message );
058            super.initCause( cause );
059            m_uri = uri;
060        }
061    
062       /**
063        * Return the controller uri.
064        * @return the uri identifying the controller that raised the exception
065        */
066        public URI getControllerURI()
067        {
068            return m_uri;
069        }
070        
071       /**
072        * Iterates through exceptiion to locate the root causal exception.
073        * @return the root exception (possibly null)
074        */ 
075        public Throwable getRootCause()
076        {
077            Throwable cause = getCause();
078            if( null == cause )
079            {
080                return null;
081            }
082            else
083            {
084                while( true )
085                {
086                    if( null == cause.getCause() )
087                    {
088                        return cause;
089                    }
090                    else
091                    {
092                        cause = cause.getCause();
093                    }
094                }
095            }
096        }
097    }
098