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1   // ========================================================================
2   // Copyright 199-2004 Mort Bay Consulting Pty. Ltd.
3   // ------------------------------------------------------------------------
4   // Licensed under the Apache License, Version 2.0 (the "License");
5   // you may not use this file except in compliance with the License.
6   // You may obtain a copy of the License at 
7   // http://www.apache.org/licenses/LICENSE-2.0
8   // Unless required by applicable law or agreed to in writing, software
9   // distributed under the License is distributed on an "AS IS" BASIS,
10  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11  // See the License for the specific language governing permissions and
12  // limitations under the License.
13  // ========================================================================
14  
15  package org.mortbay.jetty.servlet;
16  
17  import java.io.IOException;
18  import java.security.Principal;
19  import java.util.Enumeration;
20  import java.util.HashMap;
21  import java.util.Map;
22  import java.util.Stack;
23  
24  import javax.servlet.Servlet;
25  import javax.servlet.ServletConfig;
26  import javax.servlet.ServletContext;
27  import javax.servlet.ServletException;
28  import javax.servlet.ServletRequest;
29  import javax.servlet.ServletResponse;
30  import javax.servlet.SingleThreadModel;
31  import javax.servlet.UnavailableException;
32  
33  import org.mortbay.jetty.HttpConnection;
34  import org.mortbay.jetty.Request;
35  import org.mortbay.jetty.handler.ContextHandler;
36  import org.mortbay.jetty.security.SecurityHandler;
37  import org.mortbay.jetty.security.UserRealm;
38  import org.mortbay.log.Log;
39  
40  
41  
42  /* --------------------------------------------------------------------- */
43  /** Servlet Instance and Context Holder.
44   * Holds the name, params and some state of a javax.servlet.Servlet
45   * instance. It implements the ServletConfig interface.
46   * This class will organise the loading of the servlet when needed or
47   * requested.
48   *
49   * @author Greg Wilkins
50   */
51  public class ServletHolder extends Holder
52      implements Comparable
53  {
54      /* ---------------------------------------------------------------- */
55      private int _initOrder;
56      private boolean _initOnStartup=false;
57      private Map _roleMap; 
58      private String _forcedPath;
59      private String _runAs;
60      private UserRealm _realm;    
61      
62      private transient Servlet _servlet;
63      private transient Config _config;
64      private transient long _unavailable;
65      private transient UnavailableException _unavailableEx;
66  
67      
68      /* ---------------------------------------------------------------- */
69      /** Constructor .
70       */
71      public ServletHolder()
72      {}
73      
74      /* ---------------------------------------------------------------- */
75      /** Constructor for existing servlet.
76       */
77      public ServletHolder(Servlet servlet)
78      {
79          setServlet(servlet);
80      }
81  
82      /* ---------------------------------------------------------------- */
83      /** Constructor for existing servlet.
84       */
85      public ServletHolder(Class servlet)
86      {
87          super(servlet);
88      }
89  
90      /* ---------------------------------------------------------------- */
91      /**
92       * @return The unavailable exception or null if not unavailable
93       */
94      public UnavailableException getUnavailableException()
95      {
96          return _unavailableEx;
97      }
98      
99      /* ------------------------------------------------------------ */
100     public synchronized void setServlet(Servlet servlet)
101     {
102         if (servlet==null || servlet instanceof SingleThreadModel)
103             throw new IllegalArgumentException();
104 
105         _extInstance=true;
106         _servlet=servlet;
107         setHeldClass(servlet.getClass());
108         if (getName()==null)
109             setName(servlet.getClass().getName()+"-"+super.hashCode());
110     }
111     
112     /* ------------------------------------------------------------ */
113     public int getInitOrder()
114     {
115         return _initOrder;
116     }
117 
118     /* ------------------------------------------------------------ */
119     /** Set the initialize order.
120      * Holders with order<0, are initialized on use. Those with
121      * order>=0 are initialized in increasing order when the handler
122      * is started.
123      */
124     public void setInitOrder(int order)
125     {
126         _initOnStartup=true;
127         _initOrder = order;
128     }
129 
130     /* ------------------------------------------------------------ */
131     /** Comparitor by init order.
132      */
133     public int compareTo(Object o)
134     {
135         if (o instanceof ServletHolder)
136         {
137             ServletHolder sh= (ServletHolder)o;
138             if (sh==this)
139                 return 0;
140             if (sh._initOrder<_initOrder)
141                 return 1;
142             if (sh._initOrder>_initOrder)
143                 return -1;
144             
145             int c=(_className!=null && sh._className!=null)?_className.compareTo(sh._className):0;
146             if (c==0)
147                 c=_name.compareTo(sh._name);
148             if (c==0)
149                 c=this.hashCode()>o.hashCode()?1:-1;
150             return c;
151         }
152         return 1;
153     }
154 
155     /* ------------------------------------------------------------ */
156     public boolean equals(Object o)
157     {
158         return compareTo(o)==0;
159     }
160 
161     /* ------------------------------------------------------------ */
162     public int hashCode()
163     {
164         return _name==null?System.identityHashCode(this):_name.hashCode();
165     }
166 
167     /* ------------------------------------------------------------ */
168     /** Link a user role.
169      * Translate the role name used by a servlet, to the link name
170      * used by the container.
171      * @param name The role name as used by the servlet
172      * @param link The role name as used by the container.
173      */
174     public synchronized void setUserRoleLink(String name,String link)
175     {
176         if (_roleMap==null)
177             _roleMap=new HashMap();
178         _roleMap.put(name,link);
179     }
180     
181     /* ------------------------------------------------------------ */
182     /** get a user role link.
183      * @param name The name of the role
184      * @return The name as translated by the link. If no link exists,
185      * the name is returned.
186      */
187     public String getUserRoleLink(String name)
188     {
189         if (_roleMap==null)
190             return name;
191         String link=(String)_roleMap.get(name);
192         return (link==null)?name:link;
193     }
194 
195     /* ------------------------------------------------------------ */
196     public Map getRoleMap()
197     {
198         return _roleMap;
199     }
200     
201     /* ------------------------------------------------------------ */
202     /** 
203      * @param role Role name that is added to UserPrincipal when this servlet
204      * is called. 
205      */
206     public void setRunAs(String role)
207     {
208         _runAs=role;
209     }
210     
211     /* ------------------------------------------------------------ */
212     public String getRunAs()
213     {
214         return _runAs;
215     }
216     
217     /* ------------------------------------------------------------ */
218     /**
219      * @return Returns the forcedPath.
220      */
221     public String getForcedPath()
222     {
223         return _forcedPath;
224     }
225     
226     /* ------------------------------------------------------------ */
227     /**
228      * @param forcedPath The forcedPath to set.
229      */
230     public void setForcedPath(String forcedPath)
231     {
232         _forcedPath = forcedPath;
233     }
234     
235     /* ------------------------------------------------------------ */
236     public void doStart()
237     throws Exception
238     {
239         _unavailable=0;
240         try
241         {
242             super.doStart();
243             checkServletType();
244         }
245         catch (UnavailableException ue)
246         {
247             makeUnavailable(ue);
248         }
249 
250         _config=new Config();
251 
252         if (_runAs!=null)
253             _realm=((SecurityHandler)(ContextHandler.getCurrentContext()
254                     .getContextHandler().getChildHandlerByClass(SecurityHandler.class))).getUserRealm();
255 
256         if (javax.servlet.SingleThreadModel.class.isAssignableFrom(_class))
257             _servlet = new SingleThreadedWrapper();
258 
259         if (_extInstance || _initOnStartup)
260         {
261             try
262             {
263                 initServlet();
264             }
265             catch(Exception e)
266             {
267                 if (_servletHandler.isStartWithUnavailable())
268                     Log.ignore(e);
269                 else
270                     throw e;
271             }
272         }  
273     }
274 
275     /* ------------------------------------------------------------ */
276     public void doStop()
277     {
278         Principal user=null;
279         try
280         {
281             // Handle run as
282             if (_runAs!=null && _realm!=null)
283                 user=_realm.pushRole(null,_runAs);
284                 
285             if (_servlet!=null)
286             {                  
287                 try
288                 {
289                     destroyInstance(_servlet);
290                 }
291                 catch (Exception e)
292                 {
293                     Log.warn(e);
294                 }
295             }
296             
297             if (!_extInstance)
298                 _servlet=null;
299            
300             _config=null;
301         }
302         finally
303         {
304             super.doStop();
305             // pop run-as role
306             if (_runAs!=null && _realm!=null && user!=null)
307                 _realm.popRole(user); 
308         }
309     }
310 
311     /* ------------------------------------------------------------ */
312     public void destroyInstance (Object o)
313     throws Exception
314     {
315         if (o==null)
316             return;
317         Servlet servlet =  ((Servlet)o);
318         servlet.destroy();
319         getServletHandler().customizeServletDestroy(servlet);
320     }
321 
322     /* ------------------------------------------------------------ */
323     /** Get the servlet.
324      * @return The servlet
325      */
326     public synchronized Servlet getServlet()
327         throws ServletException
328     {
329         // Handle previous unavailability
330         if (_unavailable!=0)
331         {
332             if (_unavailable<0 || _unavailable>0 && System.currentTimeMillis()<_unavailable)
333                 throw _unavailableEx;
334             _unavailable=0;
335             _unavailableEx=null;
336         }
337 
338         if (_servlet==null)
339             initServlet();
340         return _servlet;
341     }
342 
343     /* ------------------------------------------------------------ */
344     /**
345      * Check to ensure class of servlet is acceptable.
346      * @throws UnavailableException
347      */
348     public void checkServletType ()
349         throws UnavailableException
350     {
351         if (!javax.servlet.Servlet.class.isAssignableFrom(_class))
352         {
353             throw new UnavailableException("Servlet "+_class+" is not a javax.servlet.Servlet");
354         }
355     }
356 
357     /* ------------------------------------------------------------ */
358     /** 
359      * @return true if the holder is started and is not unavailable
360      */
361     public boolean isAvailable()
362     {
363         if (isStarted()&& _unavailable==0)
364             return true;
365         try 
366         {
367             getServlet();
368         }
369         catch(Exception e)
370         {
371             Log.ignore(e);
372         }
373 
374         return isStarted()&& _unavailable==0;
375     }
376     
377     /* ------------------------------------------------------------ */
378     private void makeUnavailable(UnavailableException e) 
379     {
380         if (_unavailableEx==e && _unavailable!=0)
381             return;
382 
383         _servletHandler.getServletContext().log("unavailable",e);
384         
385         _unavailableEx=e;
386         _unavailable=-1;
387         if (e.isPermanent())   
388             _unavailable=-1;
389         else
390         {
391             if (_unavailableEx.getUnavailableSeconds()>0)
392                 _unavailable=System.currentTimeMillis()+1000*_unavailableEx.getUnavailableSeconds();
393             else
394                 _unavailable=System.currentTimeMillis()+5000; // TODO configure
395         }
396     }
397     
398     /* ------------------------------------------------------------ */
399     private void makeUnavailable(Throwable e) 
400     {
401         if (e instanceof UnavailableException)
402             makeUnavailable((UnavailableException)e);
403         else
404         {
405             _servletHandler.getServletContext().log("unavailable",e);
406             _unavailableEx=new UnavailableException(e.toString(),-1);
407             _unavailable=-1;
408         }
409     }
410 
411     /* ------------------------------------------------------------ */
412     private void initServlet() 
413     	throws ServletException
414     {
415         Principal user=null;
416         try
417         {
418             if (_servlet==null)
419                 _servlet=(Servlet)newInstance();
420             if (_config==null)
421                 _config=new Config();
422             
423             //handle any cusomizations of the servlet, such as @postConstruct
424             if (!(_servlet instanceof SingleThreadedWrapper))
425                 _servlet = getServletHandler().customizeServlet(_servlet);
426             
427             // Handle run as
428             if (_runAs!=null && _realm!=null)
429                 user=_realm.pushRole(null,_runAs);
430             
431             _servlet.init(_config);
432         }
433         catch (UnavailableException e)
434         {
435             makeUnavailable(e);
436             _servlet=null;
437             _config=null;
438             throw e;
439         }
440         catch (ServletException e)
441         {
442             makeUnavailable(e.getCause()==null?e:e.getCause());
443             _servlet=null;
444             _config=null;
445             throw e;
446         }
447         catch (Exception e)
448         {
449             makeUnavailable(e);
450             _servlet=null;
451             _config=null;
452             throw new ServletException(e);
453         }
454         finally
455         {
456             // pop run-as role
457             if (_runAs!=null && _realm!=null && user!=null)
458                 _realm.popRole(user);
459         }
460     }
461     
462     /* ------------------------------------------------------------ */
463     /** Service a request with this servlet.
464      */
465     public void handle(ServletRequest request,
466                        ServletResponse response)
467         throws ServletException,
468                UnavailableException,
469                IOException
470     {
471         if (_class==null)
472             throw new UnavailableException("Servlet Not Initialized");
473         
474         Servlet servlet=_servlet;
475         synchronized(this)
476         {
477             if (_unavailable!=0 || !_initOnStartup)
478                 servlet=getServlet();
479             if (servlet==null)
480                 throw new UnavailableException("Could not instantiate "+_class);
481         }
482         
483         // Service the request
484         boolean servlet_error=true;
485         Principal user=null;
486         Request base_request=null;
487         try
488         {
489             // Handle aliased path
490             if (_forcedPath!=null)
491                 // TODO complain about poor naming to the Jasper folks
492                 request.setAttribute("org.apache.catalina.jsp_file",_forcedPath);
493 
494             // Handle run as
495             if (_runAs!=null && _realm!=null)
496             {
497                 base_request=HttpConnection.getCurrentConnection().getRequest();
498                 user=_realm.pushRole(base_request.getUserPrincipal(),_runAs);
499                 base_request.setUserPrincipal(user);
500             }
501             
502             servlet.service(request,response);
503             servlet_error=false;
504         }
505         catch(UnavailableException e)
506         {
507             makeUnavailable(e);
508             throw _unavailableEx;
509         }
510         finally
511         {
512             // pop run-as role
513             if (_runAs!=null && _realm!=null && user!=null && base_request!=null)
514             {
515                 user=_realm.popRole(user);
516                 base_request.setUserPrincipal(user);
517             }
518 
519             // Handle error params.
520             if (servlet_error)
521                 request.setAttribute("javax.servlet.error.servlet_name",getName());
522         }
523     }
524 
525  
526     /* ------------------------------------------------------------ */
527     /* ------------------------------------------------------------ */
528     /* ------------------------------------------------------------ */
529     class Config implements ServletConfig
530     {   
531         /* -------------------------------------------------------- */
532         public String getServletName()
533         {
534             return getName();
535         }
536         
537         /* -------------------------------------------------------- */
538         public ServletContext getServletContext()
539         {
540             return _servletHandler.getServletContext();
541         }
542 
543         /* -------------------------------------------------------- */
544         public String getInitParameter(String param)
545         {
546             return ServletHolder.this.getInitParameter(param);
547         }
548     
549         /* -------------------------------------------------------- */
550         public Enumeration getInitParameterNames()
551         {
552             return ServletHolder.this.getInitParameterNames();
553         }
554     }
555 
556     /* -------------------------------------------------------- */
557     /* -------------------------------------------------------- */
558     /* -------------------------------------------------------- */
559     private class SingleThreadedWrapper implements Servlet
560     {
561         Stack _stack=new Stack();
562         
563         public void destroy()
564         {
565             synchronized(this)
566             {
567                 while(_stack.size()>0)
568                     try { ((Servlet)_stack.pop()).destroy(); } catch (Exception e) { Log.warn(e); }
569             }
570         }
571 
572         public ServletConfig getServletConfig()
573         {
574             return _config;
575         }
576 
577         public String getServletInfo()
578         {
579             return null;
580         }
581 
582         public void init(ServletConfig config) throws ServletException
583         {
584             synchronized(this)
585             {
586                 if(_stack.size()==0)
587                 {
588                     try
589                     {
590                         Servlet s = (Servlet) newInstance();
591                         s = getServletHandler().customizeServlet(s);
592                         s.init(config);
593                         _stack.push(s);
594                     }
595                     catch (ServletException e)
596                     {
597                         throw e;
598                     }
599                     catch (Exception e)
600                     {
601                         throw new ServletException(e);
602                     }
603                 }
604             }
605         }
606 
607         public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException
608         {
609             Servlet s;
610             synchronized(this)
611             {
612                 if(_stack.size()>0)
613                     s=(Servlet)_stack.pop();
614                 else
615                 {
616                     try
617                     {
618                         s = (Servlet) newInstance();
619                         s = getServletHandler().customizeServlet(s);
620                         s.init(_config);
621                     }
622                     catch (ServletException e)
623                     {
624                         throw e;
625                     }
626                     catch (IOException e)
627                     {
628                         throw e;
629                     }
630                     catch (Exception e)
631                     {
632                         throw new ServletException(e);
633                     }
634                 }
635             }
636             
637             try
638             {
639                 s.service(req,res);
640             }
641             finally
642             {
643                 synchronized(this)
644                 {
645                     _stack.push(s);
646                 }
647             }
648         }
649         
650     }
651 }
652 
653 
654 
655 
656