src/dolda/jsvc/util/PerSession.java

   1 package dolda.jsvc.util;
   2
   3 import dolda.jsvc.*;
   4 import java.lang.reflect.*;
   5
   6 public class PerSession implements Responder {
   7     private final Class<?> rcl;
   8     private final Class<?> dcl;
   9
  10     public PerSession(Class<?> rcl, Class<?> dcl) {
  11         this.rcl = rcl;
  12         this.dcl = dcl;
  13     }
  14
  15     public PerSession(Class<?> rcl) {
  16         this(rcl, null);
  17     }
  18
  19     private Object makedata(Session sess) {
  20         try {
  21             try {
  22                 return(dcl.getConstructor(Session.class).newInstance(sess));
  23             } catch(NoSuchMethodException e) {
  24             }
  25             try {
  26                 return(dcl.getConstructor().newInstance());
  27             } catch(NoSuchMethodException e) {
  28             }
  29         } catch(InstantiationException e) {
  30             throw(new RuntimeException(e));
  31         } catch(IllegalAccessException e) {
  32             throw(new RuntimeException(e));
  33         } catch(InvocationTargetException e) {
  34             throw(new RuntimeException(e));
  35         }
  36         throw(new RuntimeException("Found no way to create an instance of " + dcl.getName()));
  37     }
  38
  39     private Object getdata(Session sess) {
  40         Object d = sess.get(dcl, null);
  41         if(d == null) {
  42             d = makedata(sess);
  43             sess.put(dcl, d);
  44         }
  45         return(d);
  46     }
  47
  48     private Responder create(Session sess) {
  49         try {
  50             if(dcl != null) {
  51                 try {
  52                     return((Responder)rcl.getMethod("responder", dcl).invoke(null, getdata(sess)));
  53                 } catch(NoSuchMethodException e) {
  54                 }
  55             }
  56             try {
  57                 return((Responder)rcl.getMethod("responder", Session.class).invoke(null, sess));
  58             } catch(NoSuchMethodException e) {
  59             }
  60             try {
  61                 return((Responder)rcl.getMethod("responder").invoke(null));
  62             } catch(NoSuchMethodException e) {
  63             }
  64             if(dcl != null) {
  65                 try {
  66                     return((Responder)rcl.getConstructor(dcl).newInstance(getdata(sess)));
  67                 } catch(NoSuchMethodException e) {
  68                 }
  69             }
  70             try {
  71                 return((Responder)rcl.getConstructor(Session.class).newInstance(sess));
  72             } catch(NoSuchMethodException e) {
  73             }
  74             try {
  75                 return((Responder)rcl.getConstructor().newInstance());
  76             } catch(NoSuchMethodException e) {
  77             }
  78         } catch(InstantiationException e) {
  79             throw(new RuntimeException(e));
  80         } catch(IllegalAccessException e) {
  81             throw(new RuntimeException(e));
  82         } catch(InvocationTargetException e) {
  83             throw(new RuntimeException(e));
  84         }
  85         throw(new RuntimeException("Found no way to create a responder from the class " + rcl.getName()));
  86     }
  87
  88     public void respond(Request req) {
  89         Session sess = Session.get(req);
  90         Responder resp;
  91         synchronized(this) {
  92             resp = (Responder)sess.get(rcl, null);
  93             if(resp == null) {
  94                 resp = create(sess);
  95                 sess.put(rcl, resp);
  96                 if(resp instanceof Destroyable) {
  97                     final Destroyable cr = (Destroyable)resp;
  98                     sess.listen(new Session.Listener() {
  99                             public void destroy(Session sess) {
 100                                 cr.destroy();
 101                             }
 102                         });
 103                 }
 104             }
 105         }
 106         resp.respond(req);
 107     }
 108 }