001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.commons.discovery;
018    
019    
020    /**
021     * <p>An exception that is thrown only if a suitable service
022     * instance cannot be created by <code>ServiceFactory</code></p>
023     * 
024     * <p>Copied from LogConfigurationException<p>
025     *
026     * @author Craig R. McClanahan
027     * @version $Revision: 480374 $ $Date: 2006-11-29 04:33:25 +0100 (Mi, 29. Nov 2006) $
028     */
029    public class DiscoveryException extends RuntimeException {
030    
031    
032        /**
033         * Construct a new exception with <code>null</code> as its detail message.
034         */
035        public DiscoveryException() {
036            super();
037        }
038    
039        /**
040         * Construct a new exception with the specified detail message.
041         *
042         * @param message The detail message
043         */
044        public DiscoveryException(String message) {
045            super(message);
046        }
047    
048        /**
049         * Construct a new exception with the specified cause and a derived
050         * detail message.
051         *
052         * @param cause The underlying cause
053         */
054        public DiscoveryException(Throwable cause) {
055            this((cause == null) ? null : cause.toString(), cause);
056        }
057    
058        /**
059         * Construct a new exception with the specified detail message and cause.
060         *
061         * @param message The detail message
062         * @param cause The underlying cause
063         */
064        public DiscoveryException(String message, Throwable cause) {
065            super(message);
066            this.cause = cause; // Two-argument version requires JDK 1.4 or later
067        }
068    
069        /**
070         * The underlying cause of this exception.
071         */
072        protected Throwable cause = null;
073    
074        /**
075         * Return the underlying cause of this exception (if any).
076         */
077        public Throwable getCause() {
078            return this.cause;
079        }
080        
081        public String toString() {
082            String ls = System.getProperty("line.separator");
083            String str = super.toString();
084            if (cause != null) {
085                str = str + ls +
086                      "*****" + ls +
087                      stackToString(cause);
088            }
089            return str;
090        }
091    
092        private static String stackToString(Throwable e){
093          java.io.StringWriter sw= new java.io.StringWriter(1024); 
094          java.io.PrintWriter pw= new java.io.PrintWriter(sw); 
095          e.printStackTrace(pw);
096          pw.close();
097          return sw.toString();
098        }
099    }