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1   /***
2    * Licensed under the Artistic License; you may not use this file
3    * except in compliance with the License.
4    * You may obtain a copy of the License at
5    *
6    *      http://displaytag.sourceforge.net/license.html
7    *
8    * THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
9    * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
10   * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
11   */
12  package org.displaytag.exception;
13  
14  import javax.servlet.jsp.JspTagException;
15  
16  import org.apache.commons.logging.Log;
17  import org.apache.commons.logging.LogFactory;
18  import org.displaytag.Messages;
19  
20  
21  /***
22   * Base exception: extendes JspTagException providing logging and exception nesting functionalities.
23   * @author Fabrizio Giustina
24   * @version $Revision: 1.14 $ ($Author: fgiust $)
25   */
26  public abstract class BaseNestableJspTagException extends JspTagException
27  {
28  
29      /***
30       * Class where the exception has been generated.
31       */
32      private final Class sourceClass;
33  
34      /***
35       * previous exception.
36       */
37      private Throwable nestedException;
38  
39      /***
40       * Instantiate a new BaseNestableJspTagException.
41       * @param source Class where the exception is generated
42       * @param message message
43       */
44      public BaseNestableJspTagException(Class source, String message)
45      {
46          super(message);
47          this.sourceClass = source;
48  
49          // log exception
50          Log log = LogFactory.getLog(source);
51  
52          // choose appropriate logging method
53          if (getSeverity() == SeverityEnum.DEBUG)
54          {
55              log.debug(toString());
56          }
57          else if (getSeverity() == SeverityEnum.INFO)
58          {
59              log.info(toString());
60          }
61          else if (getSeverity() == SeverityEnum.WARN)
62          {
63              log.warn(toString());
64          }
65          else
66          {
67              // error - default
68              log.error(toString());
69          }
70  
71      }
72  
73      /***
74       * Instantiate a new BaseNestableJspTagException.
75       * @param source Class where the exception is generated
76       * @param message message
77       * @param cause previous Exception
78       */
79      public BaseNestableJspTagException(Class source, String message, Throwable cause)
80      {
81          super(message);
82          this.sourceClass = source;
83          this.nestedException = cause;
84  
85          // log exception
86          Log log = LogFactory.getLog(source);
87  
88          // choose appropriate logging method
89          if (getSeverity() == SeverityEnum.DEBUG)
90          {
91              log.debug(toString(), cause);
92          }
93          else if (getSeverity() == SeverityEnum.INFO)
94          {
95              log.info(toString(), cause);
96          }
97          else if (getSeverity() == SeverityEnum.WARN)
98          {
99              log.warn(toString(), cause);
100         }
101         else
102         {
103             // error - default
104             log.error(toString(), cause);
105         }
106 
107     }
108 
109     /***
110      * returns the previous exception.
111      * @return Throwable previous exception
112      */
113     public Throwable getCause()
114     {
115         return this.nestedException;
116     }
117 
118     /***
119      * basic toString. Returns the message plus the previous exception (if a previous exception exists).
120      * @return String
121      */
122     public String toString()
123     {
124         String className = this.sourceClass.getName();
125         className = className.substring(className.lastIndexOf(".")); //$NON-NLS-1$
126 
127         if (this.nestedException == null)
128         {
129             return Messages.getString("NestableException.msg", //$NON-NLS-1$
130                 new Object[]{className, getMessage()});
131         }
132 
133         return Messages.getString("NestableException.msgcause", //$NON-NLS-1$
134             new Object[]{className, getMessage(), this.nestedException.getMessage()});
135     }
136 
137     /***
138      * subclasses need to define the getSeverity method to provide correct severity for logging.
139      * @return SeverityEnum exception severity
140      * @see org.displaytag.exception.SeverityEnum
141      */
142     public abstract SeverityEnum getSeverity();
143 
144 }