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1   /*
2    * ====================================================================
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *   http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing,
14   * software distributed under the License is distributed on an
15   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16   * KIND, either express or implied.  See the License for the
17   * specific language governing permissions and limitations
18   * under the License.
19   * ====================================================================
20   *
21   * This software consists of voluntary contributions made by many
22   * individuals on behalf of the Apache Software Foundation.  For more
23   * information on the Apache Software Foundation, please see
24   * <http://www.apache.org/>.
25   *
26   */
27  
28  package org.apache.hc.core5.http;
29  
30  /**
31   * Signals that an HTTP exception has occurred.
32   *
33   * @since 4.0
34   */
35  public class HttpException extends Exception {
36  
37      private static final int FIRST_VALID_CHAR = 32;
38      private static final long serialVersionUID = -5437299376222011036L;
39  
40      /**
41       * Cleans the given String by converting characters with values less than 32 to equivalent hexadecimal codes.
42       *
43       * @param message the source string.
44       * @return a converted string.
45       */
46      static String clean(final String message) {
47          final char[] chars = message.toCharArray();
48          int i;
49          // First check to see if need to allocate a new StringBuilder
50          for (i = 0; i < chars.length; i++) {
51              if (chars[i] < FIRST_VALID_CHAR) {
52                  break;
53              }
54          }
55          if (i == chars.length) {
56              return message;
57          }
58          final StringBuilder builder = new StringBuilder(chars.length * 2);
59          for (i = 0; i < chars.length; i++) {
60              final char ch = chars[i];
61              if (ch < FIRST_VALID_CHAR) {
62                  builder.append("[0x");
63                  final String hexString = Integer.toHexString(i);
64                  if (hexString.length() == 1) {
65                      builder.append("0");
66                  }
67                  builder.append(hexString);
68                  builder.append("]");
69              } else {
70                  builder.append(ch);
71              }
72          }
73          return builder.toString();
74      }
75  
76      /**
77       * Creates a new HttpException with a {@code null} detail message.
78       */
79      public HttpException() {
80          super();
81      }
82  
83      /**
84       * Creates a new HttpException with the specified detail message.
85       *
86       * @param message the exception detail message
87       */
88      public HttpException(final String message) {
89          super(clean(message));
90      }
91  
92      /**
93       * Constructs a new HttpException with the specified detail message.
94       *
95       * @param format The exception detail message format; see {@link String#format(String, Object...)}.
96       * @param args The exception detail message arguments; see {@link String#format(String, Object...)}.
97       *
98       * @since 5.0
99       */
100     public HttpException(final String format, final Object... args) {
101         super(HttpException.clean(String.format(format, args)));
102     }
103 
104     /**
105      * Creates a new HttpException with the specified detail message and cause.
106      *
107      * @param message the exception detail message
108      * @param cause the {@code Throwable} that caused this exception, or {@code null}
109      * if the cause is unavailable, unknown, or not a {@code Throwable}
110      */
111     public HttpException(final String message, final Throwable cause) {
112         super(clean(message));
113         initCause(cause);
114     }
115 
116 }