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    1   /*
    2    * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/HttpException.java,v 1.19 2004/09/30 18:53:20 olegk Exp $
    3    * $Revision: 480424 $
    4    * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
    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: 480424 $ $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
    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 }