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Java > Open Source Codes > org > dbforms > config > DbFormsErrors


1 /*
2  * $Header: /cvsroot/jdbforms/dbforms/src/org/dbforms/config/DbFormsErrors.java,v 1.7 2004/10/20 10:51:26 hkollmann Exp $
3  * $Revision: 1.7 $
4  * $Date: 2004/10/20 10:51:26 $
5  *
6  * DbForms - a Rapid Application Development Framework
7  * Copyright (C) 2001 Joachim Peer <joepeer@excite.com>
8  *
9  * This library is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * This library is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with this library; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22  */
23 package org.dbforms.config;
24 import org.apache.commons.logging.Log;
25 import org.apache.commons.logging.LogFactory;
26
27 import org.dbforms.util.StringUtil;
28
29 import java.util.Hashtable JavaDoc;
30 import java.util.Vector JavaDoc;
31
32 import javax.servlet.ServletConfig JavaDoc;
33 import javax.servlet.ServletContext JavaDoc;
34
35
36
37 /**
38  * <p>
39  * This class gets populated with data from the dbforms-errors.xml file by the
40  * ConfigServlet. This class is a kind of "single point of entry" for error
41  * messages: it contains the definitions of error message id's, descriptions,
42  * severity etc.
43  * </p>
44  *
45  * @author Philip Grunikiewicz
46  */
47 public class DbFormsErrors {
48    private static Log logCat = LogFactory.getLog(DbFormsErrors.class.getName()); // logging category for this class
49
50    /** DOCUMENT ME! */
51    public static final String JavaDoc ERRORS = "dbformsErrors";
52
53    /** DOCUMENT ME! */
54    public static final char PARAMETER_DELIMITER = '%';
55    private Hashtable JavaDoc errorIDHash; // for quicker lookup by ID
56 private ServletConfig JavaDoc servletConfig;
57
58    /**
59     * Creates a new DbFormsErrors object.
60     */
61    public DbFormsErrors() {
62       logCat.info("Create instance of DbFormsErrors");
63       errorIDHash = new Hashtable JavaDoc();
64    }
65
66    /**
67     * DOCUMENT ME!
68     *
69     * @param id DOCUMENT ME!
70     *
71     * @return DOCUMENT ME!
72     */
73    public Error JavaDoc getErrorById(String JavaDoc id) {
74       return (Error JavaDoc) errorIDHash.get(id);
75    }
76
77
78    /**
79     * DOCUMENT ME!
80     *
81     * @param servletConfig DOCUMENT ME!
82     */
83    public void setServletConfig(ServletConfig JavaDoc servletConfig) {
84       this.servletConfig = servletConfig;
85    }
86
87
88    /**
89     * get access to configuration of config servlet
90     *
91     * @return DOCUMENT ME!
92     */
93    public ServletConfig JavaDoc getServletConfig() {
94       return servletConfig;
95    }
96
97
98    /**
99     * get access to servlet context in order to interoperate with other
100     * components of the web application
101     *
102     * @return DOCUMENT ME!
103     */
104    public ServletContext JavaDoc getServletContext() {
105       return servletConfig.getServletContext();
106    }
107
108
109    /**
110     * DOCUMENT ME!
111     *
112     * @param message DOCUMENT ME!
113     *
114     * @return DOCUMENT ME!
115     */
116    public String JavaDoc getXMLErrorMessage(String JavaDoc message) {
117       String JavaDoc langCode = null;
118       String JavaDoc language = null;
119       String JavaDoc errorCode = null;
120       String JavaDoc paramList = null;
121       org.dbforms.config.Error anError = null;
122       String JavaDoc xmlMessage = null;
123
124       // If message is empty, return immediately
125 if ((message == null) || (message.trim().length() == 0)) {
126          return null;
127       }
128
129       // Extract Language , Error Code ID, and parameters
130 // ie: English-001:FieldName,200
131 // ie: ORA-00001:Oracle Message
132 try {
133          langCode = getEmbeddedStringForErrors(message, 0, ':');
134          language = getEmbeddedStringForErrors(langCode, 0, '-');
135          errorCode = getEmbeddedStringForErrors(langCode, 1, '-');
136          paramList = getEmbeddedStringForErrors(message, 1, ':');
137       } catch (Exception JavaDoc e) {
138          //
139 logCat.error("Not in proper format - do not try to convert!");
140       }
141
142       // Reference to listing of predefined errors (xml file)
143 if (errorCode != null) {
144          // Error does not contain an id, ignore!
145 if (errorCode.trim().length() == 0) {
146             return "";
147          }
148
149          anError = getErrorById(errorCode);
150       }
151
152       // Get message associated to language
153 if (anError != null) {
154          xmlMessage = anError.getMessage(language);
155
156          if (xmlMessage != null) {
157             // Replace placeholder with supplied parameters
158 xmlMessage = insertParametersInString(xmlMessage, paramList);
159          } else {
160             xmlMessage = "No message defined! - check dbForms-error.xml";
161          }
162
163          return xmlMessage;
164       }
165
166       // An error has occured,
167 // however a custom error messages is not available
168 return message;
169    }
170
171
172    /**
173     * DOCUMENT ME!
174     *
175     * @param error DOCUMENT ME!
176     */
177    public void addError(Error JavaDoc error) {
178       logCat.info("error added: " + error);
179       errorIDHash.put(error.getId(), error);
180    }
181
182
183    /**
184     * <p>
185     * Method for parsing substring embedded by constant delimeters
186     * </p>
187     *
188     * <p>
189     * consider the following string s: English-001:param1, param2
190     * </p>
191     *
192     * <p>
193     * <pre>
194     * </pre>
195     * </p>
196     *
197     * @param str DOCUMENT ME!
198     * @param afterDelims DOCUMENT ME!
199     * @param delim DOCUMENT ME!
200     *
201     * @return DOCUMENT ME!
202     */
203    private String JavaDoc getEmbeddedStringForErrors(String JavaDoc str, int afterDelims,
204       char delim) {
205       int lastIndex = 0;
206
207       for (int i = 0; i < afterDelims; i++) {
208          lastIndex = str.indexOf(delim, lastIndex) + 1; // search end of cutting
209 }
210
211       int nextIndex = str.indexOf(delim, lastIndex); // end of cutting
212
213       if (nextIndex == -1) {
214          nextIndex = str.length();
215       }
216
217       return str.substring(lastIndex, nextIndex);
218    }
219
220
221    /**
222     * Grunikiewicz.philip 2001-12-04 Replace placeholders by parameters Make
223     * sure that parameters required = parameters provided!
224     *
225     * @param xmlMessage DOCUMENT ME!
226     * @param paramList DOCUMENT ME!
227     *
228     * @return DOCUMENT ME!
229     */
230    private String JavaDoc insertParametersInString(String JavaDoc xmlMessage, String JavaDoc paramList) {
231       // Check if their are parameters expected
232 int pos = xmlMessage.indexOf(PARAMETER_DELIMITER);
233
234       if ((pos < 0) || (paramList == null)) {
235          return xmlMessage; // No parameters found!
236 }
237
238       // Sort parameter list
239 Vector JavaDoc v = StringUtil.splitString(paramList, ",");
240       int count = 0;
241
242       while (pos >= 0) {
243          // Replace
244 String JavaDoc prefix = xmlMessage.substring(0, pos);
245          String JavaDoc suffix = xmlMessage.substring(pos + 1);
246          xmlMessage = prefix + (String JavaDoc) v.elementAt(count);
247          xmlMessage += suffix;
248          pos = xmlMessage.indexOf(PARAMETER_DELIMITER);
249          count++;
250       }
251
252       return xmlMessage;
253    }
254 }
255
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