StrutsUtil


1   /* 
2    * Copyright (C) 2006 Methodhead Software LLC.  All rights reserved.
3    * 
4    * This file is part of TransferCM.
5    * 
6    * TransferCM is free software; you can redistribute it and/or modify it under the
7    * terms of the GNU General Public License as published by the Free Software
8    * Foundation; either version 2 of the License, or (at your option) any later
9    * version.
10   * 
11   * TransferCM is distributed in the hope that it will be useful, but WITHOUT ANY
12   * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13   * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
14   * details.
15   * 
16   * You should have received a copy of the GNU General Public License along with
17   * TransferCM; if not, write to the Free Software Foundation, Inc., 51 Franklin St,
18   * Fifth Floor, Boston, MA  02110-1301  USA
19   */
20  
21  package com.methodhead.util;
22  
23  import javax.servlet.http.HttpServletRequest  ;
24  
25  import org.apache.log4j.Logger;
26  
27  import org.apache.struts.Globals;
28  import org.apache.struts.action.ActionMessage;
29  import org.apache.struts.action.ActionMessages;
30  import org.apache.struts.action.ActionError;
31  import org.apache.struts.action.ActionErrors;
32  import org.apache.struts.action.ActionMapping;
33  import org.apache.struts.action.ActionForward;
34  
35  import org.apache.struts.util.MessageResources;
36  import com.methodhead.MhfException;
37  
38  /**
39   * A collection of convenience methods for use with the Struts framework.
40   */
41  public class StrutsUtil {
42  
43    // constructors /////////////////////////////////////////////////////////////
44  
45    // constants ////////////////////////////////////////////////////////////////
46  
47    // classes //////////////////////////////////////////////////////////////////
48  
49    // methods //////////////////////////////////////////////////////////////////
50  
51    /** 
52     * Adds the <tt>msgKey</tt> message to the action messages in
53     * <tt>request</tt> for <tt>property</tt>, creating an
54     * <tt>ActionMessages</tt> object if necessary.  <tt>arg0</tt>,
55     * <tt>arg1</tt>, and <tt>arg2</tt> may be null; the appropriate
56     * <tt>ActionMessage</tt> constructor will be used.  If the message is not
57     * defined, a warning is logged.  If <tt>property</tt> is <tt>null</tt>,
58     * <tt>ActionErrors.GLOBAL_MESSAGE</tt> is assumed.
59     */
60    public static void addMessage(
61      HttpServletRequest   request,
62      String   property,
63      String   msgKey,
64      Object   arg0,
65      Object   arg1,
66      Object   arg2 ) {
67  
68      //
69      // force the property if it hasn't been supplied
70      //
71      if ( property == null ) {
72        property = ActionMessages.GLOBAL_MESSAGE;
73      }
74  
75      //
76      // get the action messages
77      //
78      ActionMessages messages =
79        ( ActionMessages )request.getAttribute( Globals.MESSAGE_KEY );
80  
81      if ( messages == null ) {
82        messages = new ActionMessages();
83        request.setAttribute( Globals.MESSAGE_KEY, messages );
84      }
85  
86      //
87      // get the particular message
88      //
89      MessageResources messageResources =
90        ( MessageResources )request.getAttribute( Globals.MESSAGES_KEY );
91  
92      if ( messageResources == null )
93        throw new MhfException( "Message resources is null." );
94  
95      String   message = messageResources.getMessage( msgKey );
96  
97      if ( message == null )
98        logger_.warn( msgKey + " resource message is not defined." );
99  
100     //
101     // instantiate the appropriate message
102     //
103     ActionMessage actionMessage = null;
104     if ( arg0 == null )
105       actionMessage = new ActionMessage( msgKey );
106     else if ( arg1 == null )
107       actionMessage = new ActionMessage( msgKey, arg0 );
108     else if ( arg2 == null )
109       actionMessage = new ActionMessage( msgKey, arg0, arg1 );
110     else
111       actionMessage = new ActionMessage( msgKey, arg0, arg1, arg2 );
112 
113     //
114     // add the message
115     //
116     messages.add( property, actionMessage );
117   }
118 
119   /** 
120    * Adds the <tt>msgKey</tt> message to the action errors in
121    * <tt>request</tt> for <tt>property</tt>, creating an
122    * <tt>ActionErrors</tt> object if necessary.  <tt>arg0</tt>,
123    * <tt>arg1</tt>, and <tt>arg2</tt> may be null; the appropriate
124    * <tt>ActionMessage</tt> constructor will be used.  If the message is not
125    * defined, a warning is logged.  If <tt>property</tt> is <tt>null</tt>,
126    * <tt>ActionErrors.GLOBAL_ERROR</tt> is assumed.
127    */
128   public static void addError(
129     HttpServletRequest   request,
130     String   property,
131     String   msgKey,
132     Object   arg0,
133     Object   arg1,
134     Object   arg2 ) {
135 
136     //
137     // force the property if it hasn't been supplied
138     //
139     if ( property == null ) {
140       property = ActionErrors.GLOBAL_ERROR;
141     }
142 
143     //
144     // get the action messages
145     //
146     ActionErrors messages =
147       ( ActionErrors )request.getAttribute( Globals.ERROR_KEY );
148 
149     if ( messages == null ) {
150       messages = new ActionErrors();
151       request.setAttribute( Globals.ERROR_KEY, messages );
152     }
153 
154     //
155     // get the particular message
156     //
157     MessageResources messageResources =
158       ( MessageResources )request.getAttribute( Globals.MESSAGES_KEY );
159 
160     String   message = messageResources.getMessage( msgKey );
161 
162     if ( message == null )
163       logger_.warn( msgKey + " resource message is not defined." );
164 
165     //
166     // instantiate the appropriate message
167     //
168     ActionError actionMessage = null;
169     if ( arg0 == null )
170       actionMessage = new ActionError( msgKey );
171     else if ( arg1 == null )
172       actionMessage = new ActionError( msgKey, arg0 );
173     else if ( arg2 == null )
174       actionMessage = new ActionError( msgKey, arg0, arg1 );
175     else
176       actionMessage = new ActionError( msgKey, arg0, arg1, arg2 );
177 
178     //
179     // add the message
180     //
181     messages.add( property, actionMessage );
182   }
183 
184   /** 
185    * Adds a message as in {@link
186    * #addMessage(javax.servlet.http.HttpServletRequest,java.lang.String,java.lang.String,java.lang.Object,java.lang.Object,java.lang.Object) addMessage()}, assuming the <tt>GLOBAL_MESSAGE</tt> property.
187    */
188   public static void addMessage(
189     HttpServletRequest   request,
190     String   msgKey,
191     Object   arg0,
192     Object   arg1,
193     Object   arg2 ) {
194 
195     addMessage(
196       request, ActionMessages.GLOBAL_MESSAGE, msgKey, arg0, arg1, arg2 );
197   }
198 
199   /**
200    * Adds a message to the request's action messages, creating a new
201    * <tt>ActionMessages</tt> object if necessary.  An warning is logged if no
202    * message exists for <tt>msgKey</tt>.
203    * @deprecated Use {@link #addMessage(javax.servlet.http.HttpServletRequest,java.lang.String,java.lang.String,java.lang.Object,java.lang.Object,java.lang.Object) addMessage()}
204    */
205   public static void addMessage(
206     HttpServletRequest   request,
207     MessageResources messageResources,
208     String   property,
209     String   msgKey,
210     Object   arg0 ) {
211 
212     ActionMessages messages =
213       ( ActionMessages )request.getAttribute( Globals.MESSAGE_KEY );
214 
215     if ( messages == null )
216       messages = new ActionMessages();
217 
218     String   message = messageResources.getMessage( msgKey );
219     if ( message == null )
220       logger_.warn( msgKey + " resource message is not defined." );
221 
222     messages.add(
223       property, new ActionMessage( msgKey, arg0 ) );
224 
225     request.setAttribute( Globals.MESSAGE_KEY, messages );
226   }
227 
228   /**
229    * Adds a message to the request's action messages, creating a new
230    * <tt>ActionMessages</tt> object if necessary.  An warning is logged if no
231    * message exists for <tt>msgKey</tt>.
232    * @deprecated Use {@link #addMessage(javax.servlet.http.HttpServletRequest,java.lang.String,java.lang.String,java.lang.Object,java.lang.Object,java.lang.Object) addMessage()}
233    */
234   public static void addMessage(
235     HttpServletRequest   request,
236     MessageResources messageResources,
237     String   property,
238     String   msgKey,
239     Object   arg0,
240     Object   arg1 ) {
241 
242     ActionMessages messages =
243       ( ActionMessages )request.getAttribute( Globals.MESSAGE_KEY );
244 
245     if ( messages == null )
246       messages = new ActionMessages();
247 
248     String   message = messageResources.getMessage( msgKey );
249     if ( message == null )
250       logger_.warn( msgKey + " resource message is not defined." );
251 
252     messages.add(
253       property, new ActionMessage( msgKey, arg0, arg1 ) );
254 
255     request.setAttribute( Globals.MESSAGE_KEY, messages );
256   }
257 
258   /**
259    * Adds a message to the request's action messages, creating a new
260    * <tt>ActionMessages</tt> object if necessary.  An warning is logged if no
261    * message exists for <tt>msgKey</tt>.
262    * @deprecated Use {@link #addMessage(javax.servlet.http.HttpServletRequest,java.lang.String,java.lang.String,java.lang.Object,java.lang.Object,java.lang.Object) addMessage()}
263    */
264   public static void addMessage(
265     HttpServletRequest   request,
266     MessageResources messageResources,
267     String   property,
268     String   msgKey,
269     Object   arg0,
270     Object   arg1,
271     Object   arg2 ) {
272 
273     ActionMessages messages =
274       ( ActionMessages )request.getAttribute( Globals.MESSAGE_KEY );
275 
276     if ( messages == null )
277       messages = new ActionMessages();
278 
279     String   message = messageResources.getMessage( msgKey );
280     if ( message == null )
281       logger_.warn( msgKey + " resource message is not defined." );
282 
283     messages.add(
284       property, new ActionMessage( msgKey, arg0, arg1, arg2 ) );
285 
286     request.setAttribute( Globals.MESSAGE_KEY, messages );
287   }
288 
289   /**
290    * Returns the forward named <tt>name</tt> or throws an exception
291    * with a message indicating the forward could not be found.
292    */
293   public static ActionForward findForward(
294     ActionMapping mapping,
295     String   name ) {
296 
297     ActionForward forward = mapping.findForward( name );
298 
299     if ( forward == null )
300       throw new MhfException( "Couldn't find \"" + name + "\" forward" );
301 
302     return forward;
303   }
304 
305   /**
306    * NOT UNIT TESTED Instantiates the policy specified by <tt>mapping</tt>'s
307    * parameter.
308    */
309   public static Object   getPolicy(
310     ActionMapping mapping ) {
311 
312     try {
313       return
314         Class.forName( mapping.getParameter() ).newInstance();
315     }
316     catch ( Exception   e ) {
317       throw new MhfException(
318         "Unexpected exception while instantiating \"" +
319         mapping.getParameter() +"\":" + e.toString() );
320     }
321   }
322 
323   // properties ///////////////////////////////////////////////////////////////
324 
325   // attributes ///////////////////////////////////////////////////////////////
326 
327   private static Logger logger_ = Logger.getLogger( "StrutsUtil" );
328 }
329
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