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1   /*
2    * $HeadURL: https://svn.apache.org/repos/asf/httpcomponents/oac.hc3x/trunk/src/java/org/apache/commons/httpclient/HttpException.java $
3    * $Revision: 1425331 $
4    * $Date: 2012-12-22 19:29:41 +0100 (Sat, 22 Dec 2012) $
5    *
6    * ====================================================================
7    *
8    *  Licensed to the Apache Software Foundation (ASF) under one or more
9    *  contributor license agreements.  See the NOTICE file distributed with
10   *  this work for additional information regarding copyright ownership.
11   *  The ASF licenses this file to You under the Apache License, Version 2.0
12   *  (the "License"); you may not use this file except in compliance with
13   *  the License.  You may obtain a copy of the License at
14   *
15   *      http://www.apache.org/licenses/LICENSE-2.0
16   *
17   *  Unless required by applicable law or agreed to in writing, software
18   *  distributed under the License is distributed on an "AS IS" BASIS,
19   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20   *  See the License for the specific language governing permissions and
21   *  limitations under the License.
22   * ====================================================================
23   *
24   * This software consists of voluntary contributions made by many
25   * individuals on behalf of the Apache Software Foundation.  For more
26   * information on the Apache Software Foundation, please see
27   * <http://www.apache.org/>.
28   *
29   */
30  
31  package org.apache.commons.httpclient;
32  
33  import java.io.IOException;
34  import java.io.PrintStream;
35  import java.io.PrintWriter;
36  import java.lang.reflect.Method;
37  
38  /***
39   * Signals that an HTTP or HttpClient exception has occurred.
40   * 
41   * @author Laura Werner
42   * 
43   * @version $Revision: 1425331 $ $Date: 2012-12-22 19:29:41 +0100 (Sat, 22 Dec 2012) $
44   */
45  public class HttpException extends IOException {
46  
47      /***
48       * Creates a new HttpException with a <tt>null</tt> detail message.
49       */
50      public HttpException() {
51          super();
52          this.cause = null;
53      }
54  
55      /***
56       * Creates a new HttpException with the specified detail message.
57       *
58       * @param message the exception detail message
59       */
60      public HttpException(String message) {
61          super(message);
62          this.cause = null;
63      }
64  
65      /***
66       * Creates a new HttpException with the specified detail message and cause.
67       * 
68       * @param message the exception detail message
69       * @param cause the <tt>Throwable</tt> that caused this exception, or <tt>null</tt>
70       * if the cause is unavailable, unknown, or not a <tt>Throwable</tt>
71       * 
72       * @since 3.0
73       */
74      public HttpException(String message, Throwable cause) {
75          super(message);
76          this.cause = cause;
77          
78          // If we're running on JDK 1.4 or later, tell Throwable what the cause was
79          try {
80              Class[] paramsClasses = new Class[] { Throwable.class };
81              Method initCause = Throwable.class.getMethod("initCause", paramsClasses);
82              initCause.invoke(this, new Object[] { cause });
83          } catch (Exception e) {
84              // The setCause method must not be available
85          }
86      }
87  
88      /***
89       * Return the <tt>Throwable</tt> that caused this exception, or <tt>null</tt>
90       *         if the cause is unavailable, unknown, or not a <tt>Throwable</tt>.
91       * 
92       * @return the <tt>Throwable</tt> that caused this exception, or <tt>null</tt>
93       *         if the cause is unavailable, unknown, or not a <tt>Throwable</tt>
94       * 
95       * @since 3.0
96       */
97      public Throwable getCause() {
98          return cause;
99      }
100 
101     /***
102      * Print this HttpException and its stack trace to the standard error stream.
103      * 
104      * @since 3.0
105      */
106     public void printStackTrace() {
107         printStackTrace(System.err);
108     }
109 
110     /***
111      * Print this HttpException and its stack trace to the specified print stream.
112      * 
113      * @param s the <tt>PrintStream</tt> to which the exception and its stack trace
114      * should be written
115      * 
116      * @since 3.0
117      */
118     public void printStackTrace(PrintStream s) {
119         try {
120             // JDK 1.4 has a nice printStackTrace method that prints the cause's stack
121             // trace too and prunes out duplicate stack frames.  Call it if possible,
122             // which is determined by checking whether JDK 1.4's getStackTrace method is present 
123             Class[] paramsClasses = new Class[] {  };
124             this.getClass().getMethod("getStackTrace", paramsClasses);
125             super.printStackTrace(s);
126         } catch (Exception ex) {
127             // If that didn't work, print it out ourselves
128             // First print this exception's stack trace.
129             super.printStackTrace(s);
130             if (cause != null) {
131                 // Print out the exception that caused this one.
132                 // This will recurse if the cause is another HttpException.
133                 s.print("Caused by: ");
134                 cause.printStackTrace(s);
135             }
136         }
137     }
138 
139     /***
140      * Print this HttpException and its stack trace to the specified print writer.
141      * 
142      * @param s the <tt>PrintWriter</tt> to which the exception and its stack trace
143      * should be written
144      * 
145      * @since 3.0
146      */
147     public void printStackTrace(PrintWriter s) {
148         try {
149             // JDK 1.4 has a nice printStackTrace method that prints the cause's stack
150             // trace too and prunes out duplicate stack frames.  Call it if possible,
151             // which is determined by checking whether JDK 1.4's getStackTrace method is present 
152             Class[] paramsClasses = new Class[] {  };
153             this.getClass().getMethod("getStackTrace", paramsClasses);
154             super.printStackTrace(s);
155         } catch (Exception ex) {
156             // If that didn't work, print it out ourselves
157             // First print this exception's stack trace.
158             super.printStackTrace(s);
159             if (cause != null) {
160                 // Print out the exception that caused this one.
161                 // This will recurse if the cause is another HttpException.
162                 s.print("Caused by: ");
163                 cause.printStackTrace(s);
164             }
165         }
166     }
167 
168     /***
169      * Sets the text description of the reason for an exception.
170      *
171      * @param reason The reason for the exception.
172      *
173      * @deprecated HttpClient no longer uses this for itself.  It is only
174      * provided for compatibility with existing clients, and will be removed
175      * in a future release.
176      */
177     public void setReason(String reason) {
178         this.reason = reason;
179     }
180 
181     /***
182      * Get the text description of the reason for an exception.
183      *
184      * @deprecated HttpClient no longer uses this for itself.  It is only
185      * provided for compatibility with existing clients, and will be removed
186      * in a future release.
187      */
188     public String getReason() {
189         return reason;
190     }
191 
192     /***
193      * Sets the status code description of the reason for an exception.
194      *
195      * @param code The reason for the exception.  This is intended to be an
196      *  HTTP status code.
197      *
198      * @deprecated HttpClient no longer uses this for itself.  It is only
199      * provided for compatibility with existing clients, and will be removed
200      * in a future release.
201      */
202     public void setReasonCode(int code) {
203         reasonCode = code;
204     }
205 
206     /***
207      * Get the status code description of the reason for an exception.
208      *
209      * @deprecated HttpClient no longer uses this for itself.  It is only
210      * provided for compatibility with existing clients, and will be removed
211      * in a future release.
212      */
213     public int getReasonCode() {
214         return this.reasonCode;
215     }
216 
217     /***
218      * A "reason" string provided for compatibility with older clients.
219      *
220      * @deprecated HttpClient no longer uses this field for itself.  It
221      * is only provided for compatibility with existing clients.
222      */
223     private String reason;
224 
225     /***
226      * Reason code for compatibility with older clients.
227      *
228      * @deprecated  HttpClient no longer uses this field for itself.
229      *  It is only provided for compatibility with existing clients.
230      */
231     private int reasonCode = HttpStatus.SC_OK;
232 
233     /*** The original Throwable representing the cause of this error */
234     private final Throwable cause;
235 }