StateAdaptor


1   // ========================================================================
2   // $Id: StateAdaptor.java,v 1.4 2004/05/09 20:30:47 gregwilkins Exp $
3   // Copyright 2002-2004 Mort Bay Consulting Pty. Ltd.
4   // ------------------------------------------------------------------------
5   // Licensed under the Apache License, Version 2.0 (the "License");
6   // you may not use this file except in compliance with the License.
7   // You may obtain a copy of the License at 
8   // http://www.apache.org/licenses/LICENSE-2.0
9   // Unless required by applicable law or agreed to in writing, software
10  // distributed under the License is distributed on an "AS IS" BASIS,
11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  // See the License for the specific language governing permissions and
13  // limitations under the License.
14  // ========================================================================
15  
16  package org.mortbay.j2ee.session;
17  
18  //----------------------------------------
19  
20  import java.rmi.RemoteException  ;
21  import java.util.Enumeration  ;
22  
23  import javax.servlet.ServletContext  ;
24  import javax.servlet.http.HttpSessionContext  ;
25  
26  import org.jfox.ioc.logger.Logger;
27  
28  //----------------------------------------
29  // this class is responsible for presenting a State container to a
30  // servlet as a HttpSession - since this interface is not an ideal one
31  // to use for the container interceptors. It constrains all the inputs
32  // to this API as specified...
33  
34  // Since this is the front end of the Container, maybe it should be so
35  // called ? or maybe I should just call it [Http]Session?
36  
37  // we should cache our id locally...
38  
39  public class StateAdaptor
40    implements org.mortbay.jetty.servlet.SessionManager.Session
41  {
42    protected static final Logger _log=Logger.getLogger(StateAdaptor.class);
43    Manager        _manager;
44    State          _state=null;
45    boolean        _new=true;
46  
47    // we cache these for speed...
48    final String   _id;
49  
50    StateAdaptor(String   id, Manager manager, int maxInactiveInterval, long lastAccessedTime)
51    {
52      _id=id;
53      _manager=manager;
54    }
55  
56    void
57      setState(State state)
58    {
59      _state=state;
60    }
61  
62    State
63      getState()
64    {
65      return _state;
66    }
67  
68    // hmmmm...
69    // why does Greg call this?
70    // could it be compressed into a subsequent call ?
71    public boolean
72      isValid()
73    {
74      if (_state==null)
75        return false;
76  
77      StateInterceptor si=(StateInterceptor)_state;
78       si.setManager(_manager);
79       si.setSession(this);
80  
81      try
82      {
83        _state.getLastAccessedTime(); // this should cause an interceptor/the session to check
84        return true;
85      }
86      catch (IllegalStateException   ignore)
87      {
88        return false;
89      }
90      catch (Exception   e)
91      {
92        _log.error("problem contacting HttpSession", e);
93        return false;
94      }
95    }
96  
97    // HttpSession API
98  
99    public long
100     getCreationTime()
101     throws IllegalStateException  
102   {
103     checkState();
104 
105     try
106     {
107       return _state.getCreationTime();
108     }
109     catch (RemoteException   e)
110     {
111       _log.error("could not get CreationTime", e);
112       throw new IllegalStateException  ("problem with distribution layer");
113     }
114   }
115 
116   public String  
117     getId()
118     throws IllegalStateException  
119   {
120     checkState();
121 
122     // locally cached and invariant
123     return _id;
124   }
125 
126   public long
127     getLastAccessedTime()
128     throws IllegalStateException  
129   {
130     checkState();
131 
132     try
133     {
134       return _state.getLastAccessedTime();
135     }
136     catch (RemoteException   e)
137     {
138       _log.error("could not get LastAccessedTime", e);
139       throw new IllegalStateException  ("problem with distribution layer");
140     }
141   }
142 
143   // clarify with Tomcat, whether this is on a per Session or SessionManager basis...
144   public void
145     setMaxInactiveInterval(int interval)
146   {
147     checkState();
148 
149     try
150     {
151       _state.setMaxInactiveInterval(interval);
152     }
153     catch (RemoteException   e)
154     {
155       _log.error("could not set MaxInactiveInterval", e);
156     }
157   }
158 
159   public int
160     getMaxInactiveInterval()
161   {
162     checkState();
163 
164     try
165     {
166       return _state.getMaxInactiveInterval();
167     }
168     catch (RemoteException   e)
169     {
170       // Can I throw an exception of some type here - instead of
171       // returning rubbish ? - TODO
172       _log.error("could not get MaxInactiveInterval", e);
173       return 0;
174     }
175   }
176 
177   public Object  
178     getAttribute(String   name)
179     throws IllegalStateException  
180   {
181     checkState();
182 
183     try
184     {
185       return _state.getAttribute(name);
186     }
187     catch (RemoteException   e)
188     {
189       _log.error("could not get Attribute", e);
190       throw new IllegalStateException  ("problem with distribution layer");
191     }
192   }
193 
194   public Object  
195     getValue(String   name)
196     throws IllegalStateException  
197   {
198     checkState();
199 
200     try
201     {
202       return _state.getAttribute(name);
203     }
204     catch (RemoteException   e)
205     {
206       _log.error("could not get Value", e);
207       throw new IllegalStateException  ("problem with distribution layer");
208     }
209   }
210 
211   public Enumeration  
212     getAttributeNames()
213     throws IllegalStateException  
214   {
215     checkState();
216 
217     try
218     {
219       return _state.getAttributeNameEnumeration();
220     }
221     catch (RemoteException   e)
222     {
223       _log.error("could not get AttributeNames", e);
224       throw new IllegalStateException  ("problem with distribution layer");
225     }
226   }
227 
228   public String  []
229     getValueNames()
230     throws IllegalStateException  
231   {
232     checkState();
233 
234     try
235     {
236       return _state.getAttributeNameStringArray();
237     }
238     catch (RemoteException   e)
239     {
240       _log.error("could not get ValueNames", e);
241       throw new IllegalStateException  ("problem with distribution layer");
242     }
243   }
244 
245   public void
246     setAttribute(String   name, Object   value)
247     throws IllegalStateException  
248   {
249     checkState();
250 
251     try
252     {
253       if (value==null)
254     _state.removeAttribute(name, false);
255       else
256       {
257     if (name==null)
258       throw new IllegalArgumentException  ("invalid attribute name: "+name);
259 
260     _state.setAttribute(name, value, false);
261       }
262     }
263     catch (RemoteException   e)
264     {
265       _log.error("could not set Attribute", e);
266       throw new IllegalStateException  ("problem with distribution layer");
267     }
268   }
269 
270   public void
271     putValue(String   name, Object   value)
272     throws IllegalStateException  
273   {
274     checkState();
275 
276     if (name==null)
277       throw new IllegalArgumentException  ("invalid attribute name: "+name);
278 
279     if (value==null)
280       throw new IllegalArgumentException  ("invalid attribute value: "+value);
281 
282     try
283     {
284       _state.setAttribute(name, value, false);
285     }
286     catch (RemoteException   e)
287     {
288       _log.error("could not put Value", e);
289       throw new IllegalStateException  ("problem with distribution layer");
290     }
291   }
292 
293   public void
294     removeAttribute(String   name)
295     throws IllegalStateException  
296   {
297     checkState();
298 
299     try
300     {
301       _state.removeAttribute(name, false);
302     }
303     catch (RemoteException   e)
304     {
305       _log.error("could not remove Attribute", e);
306       throw new IllegalStateException  ("problem with distribution layer");
307     }
308   }
309 
310   public void
311     removeValue(String   name)
312     throws IllegalStateException  
313   {
314     checkState();
315 
316     try
317     {
318       _state.removeAttribute(name, false);
319     }
320     catch (RemoteException   e)
321     {
322       _log.error("could not remove Value", e);
323       throw new IllegalStateException  ("problem with distribution layer");
324     }
325   }
326 
327   public void
328     invalidate()
329     throws IllegalStateException  
330   {
331     if (_log.isTraceEnabled()) _log.trace("user invalidated session: "+getId());
332     _manager.destroySession(this);
333   }
334 
335   /**
336    *
337    * Returns <code>true</code> if the client does not yet know about the
338    * session or if the client chooses not to join the session.  For
339    * example, if the server used only cookie-based sessions, and
340    * the client had disabled the use of cookies, then a session would
341    * be new on each request.
342    *
343    * @return                <code>true</code> if the
344    *                    server has created a session,
345    *                    but the client has not yet joined
346    *
347    * @exception IllegalStateException   if this method is called on an
348    *                    already invalidated session
349    *
350    */
351 
352   public boolean
353     isNew()
354     throws IllegalStateException  
355   {
356     return _new;
357   }
358 
359   public ServletContext  
360     getServletContext()
361   {
362     return _manager.getServletContext();
363   }
364 
365   public HttpSessionContext  
366     getSessionContext()
367   {
368     return _manager.getSessionContext();
369   }
370 
371   // this one's for Greg...
372   public void
373     access()
374   {
375     long time=System.currentTimeMillis(); // we could get this from Manager - less accurate
376     setLastAccessedTime(time);
377 
378     _new=false;         // synchronise - TODO
379   }
380 
381   public void
382     setLastAccessedTime(long time)
383     throws IllegalStateException  
384   {
385     checkState();
386 
387     try
388     {
389       _state.setLastAccessedTime(time);
390     }
391     catch (RemoteException   e)
392     {
393       _log.error("could not set LastAccessedTime", e);
394       throw new IllegalStateException  ("problem with distribution layer");
395     }
396   }
397 
398   protected void
399     checkState()
400     throws IllegalStateException  
401   {
402     if (_state==null)
403       throw new IllegalStateException  ("invalid session");
404 
405     // this is a hack to get new interceptor stack to work... - TODO
406     StateInterceptor si=(StateInterceptor)_state;
407      si.setManager(_manager);
408      si.setSession(this);
409   }
410 
411   public String  
412     toString()
413   {
414     return "<"+getClass()+"->"+_state+">";
415   }
416 
417   // I'm still not convinced that this is the correct place for this
418   // method- but I can;t think of a better way - maybe in the next
419   // iteration...
420 
421 //   MigrationInterceptor _mi=null;
422 //
423 //   public void
424 //     registerMigrationListener(MigrationInterceptor mi)
425 //   {
426 //     _mi=mi;
427 //   }
428 //
429    public void
430      migrate()
431    {
432      //     if (_mi!=null)
433      //       _mi.migrate(); // yeugh - TODO
434    }
435 }
436
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