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1   /*
2   Karma core - Core of the Karma application
3   Copyright (C) 2004  Toolforge <www.toolforge.nl>
4   
5   This library is free software; you can redistribute it and/or
6   modify it under the terms of the GNU Lesser General Public
7   License as published by the Free Software Foundation; either
8   version 2.1 of the License, or (at your option) any later version.
9   
10  This library is distributed in the hope that it will be useful,
11  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  Lesser General Public License for more details.
14  
15  You should have received a copy of the GNU Lesser General Public
16  License along with this library; if not, write to the Free Software
17  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  */
19  package nl.toolforge.karma.core;
20  
21  import org.apache.commons.logging.Log;
22  import org.apache.commons.logging.LogFactory;
23  
24  import java.text.MessageFormat;
25  import java.util.Locale;
26  import java.util.MissingResourceException;
27  import java.util.ResourceBundle;
28  
29  /***
30   * <p>Class representing a Karma errorcode. These errorcodes are localized to support different languages. Errorcodes
31   * are defined in ranges. Exceptions that are supported by Karma, define these ranges.</p>
32   *
33   * @author D.A. Smedes
34   * @version $Id: ErrorCode.java,v 1.17 2004/11/10 22:06:33 asmedes Exp $
35   */
36  public final class ErrorCode {
37  
38    private static Log logger = LogFactory.getLog(ErrorCode.class);
39  
40    private static Locale currentLocale = null;
41  
42    private Object[] messageArguments = new Object[]{};
43  
44    private ResourceBundle messageBundle = null;
45  
46    static {
47  
48      // todo : ensure that LocalEnvironment knows about the current Locale and pass it on to here.
49      //
50      currentLocale = Locale.ENGLISH;
51    }
52  
53    private String errorCode = null;
54  
55    /***
56     * Creates an error code. Error codes must comply to the following pattern : <code>[A-Z]{3}-\d{5}</code>. Examples are:
57     * <code>MAN-00001</code>, <code>CMD-10020</code>.
58     *
59     * @param errorCode
60     */
61    public ErrorCode(String errorCode) {
62  
63      if (!errorCode.matches("[A-Z]{3}-//d{5}")) {
64        throw new IllegalArgumentException("Illegal error code format.");
65      }
66      this.errorCode = errorCode;
67    }
68  
69    public void setMessageBundle(ResourceBundle messageBundle) {
70      this.messageBundle = messageBundle;
71    }
72  
73    /***
74     * Assigns message arguments to this error code as per the <code>MessageFormat</code> definition.
75     *
76     * @param messageArguments An Object array (currently only <code>String</code> instances are supported).
77     */
78    public final void setMessageArguments(Object[] messageArguments) {
79      this.messageArguments = messageArguments;
80    }
81  
82    /***
83     * <p>Gets a localized error message for the <code>ErrorCode</code> instance. Error messages are defined in a
84     * <code>error-messages-&lt;locale&gt;.properties</code> (e.g. <code>error-messages-NL.properties</code>). A message
85     * text is identified by a key <code>message.</code> concatenated with {@link #getErrorCodeString}.
86     * <p/>
87     * </p>When no resource bundle can be found for <code>locale</code>, the default locale <code>Locale.ENGLISH</code> is
88     * used.
89     *
90     * @param locale A locale object (e.g. representing the current locale of the user environment).
91     * @return A localized error message or {@link #getErrorCodeString} when no message was found for this errorcode or the
92     *   resourcebundle could not be found for <code>locale</code>.
93     */
94    public String getErrorMessage(Locale locale) {
95  
96      if (locale == null) {
97        locale = currentLocale;
98      }
99  
100     String message = "";
101 
102     if (messageBundle == null) {
103       try {
104         locale = Locale.ENGLISH;
105         messageBundle = ResourceBundle.getBundle("error-messages", locale);
106       } catch (MissingResourceException m) {
107         logger.error("No default resource bundle available for locale " + locale);
108         return getErrorCodeString();
109       }
110     }
111 
112     try {
113       message = messageBundle.getString("message." + getErrorCodeString());
114 
115       if (getMessageArguments().length != 0) {
116         MessageFormat messageFormat = new MessageFormat(message);
117         message = messageFormat.format(getMessageArguments());
118       }
119 
120     } catch (RuntimeException r) {
121       logger.error("No message found for errorcode : " + getErrorCodeString());
122       message = getErrorCodeString();
123     }
124 
125     if (message.startsWith(getErrorCodeString())) {
126       return message;
127     }
128 
129     return getErrorCodeString() + " : " + message;
130   }
131 
132   /***
133    * Gets the error message for the current locale.
134    *
135    * @return The error message for the error code.
136    */
137   public String getErrorMessage() {
138     return getErrorMessage(currentLocale);
139   }
140 
141   /***
142    * Gets this instance' error code.
143    *
144    * @return This instance' error code.
145    */
146   public String getErrorCodeString() {
147     return errorCode;
148   }
149 
150   private Object[] getMessageArguments() {
151     return (messageArguments == null ? new Object[0] : messageArguments);
152   }
153 
154   public boolean equals(Object o) {
155     if (this == o) return true;
156     if (!(o instanceof ErrorCode)) return false;
157 
158     final ErrorCode errorCode1 = (ErrorCode) o;
159 
160     if (errorCode != null ? !errorCode.equals(errorCode1.errorCode) : errorCode1.errorCode != null) return false;
161 
162     return true;
163   }
164 
165   public int hashCode() {
166     return (errorCode != null ? errorCode.hashCode() : 0);
167   }
168 
169   public String toString() {
170     return errorCode;
171   }
172 
173 }
174