问jheatbugs-2001-03-28中某些代码

sybbk

HeatbugModelSwarm中buildActions部分，3个try分别是做什么？查了下refbook-java-2.2，解释太简略，还是不懂，高手指点，谢谢！代码如下：

1 `3 R- |7 B( L3 Y* Y7 m  q$ w' S public Object buildActions () {
    super.buildActions();
   
9 N. T- F/ O% a- ~) S" X    // Create the list of simulation actions. We put these in
5 x, g8 X* S( T2 ]5 U. }; ~7 K    // an action group, because we want these actions to be
3 S8 A4 j, a% X% s! L  y    // executed in a specific order, but these steps should
8 [2 h  e7 q3 r, I    // take no (simulated) time. The M(foo) means "The message
    // called <foo>". You can send a message To a particular
5 Z1 q+ s+ @% Z5 i! x    // object, or ForEach object in a collection.
; p7 p9 @7 y9 J- E1 Q/ \        
    // Note we update the heatspace in two phases: first run
    // diffusion, then run "updateWorld" to actually enact the
/ c& a8 C1 p4 Z  y    // changes the heatbugs have made. The ordering here is
    // significant!
# E+ L; H+ ~2 {! N* r        
    // Note also, that with the additional
/ h7 d; r$ E1 b    // `randomizeHeatbugUpdateOrder' Boolean flag we can
    // randomize the order in which the bugs actually run
    // their step rule.  This has the effect of removing any
    // systematic bias in the iteration throught the heatbug
    // list from timestep to timestep
        
$ v2 Y  G& E, |$ k/ b, u) _1 v, M5 X, S    // By default, all `createActionForEach' modelActions have
2 q; N4 V% F# E) o    // a default order of `Sequential', which means that the
) `9 Z) ?! ^: @1 t% {; j6 b    // order of iteration through the `heatbugList' will be
    // identical (assuming the list order is not changed
    // indirectly by some other process).
   
0 y: h- @& ]/ L; v) I8 x+ a) o    modelActions = new ActionGroupImpl (getZone ());
: j" M5 @7 D$ [: d% R
0 r. ]7 ?! o: x+ [" ]  y" j    try {
6 \' B! S9 o  k      modelActions.createActionTo$message
% j2 ]& n3 j/ j; A        (heat, new Selector (heat.getClass (), "stepRule", false));
    } catch (Exception e) {
      System.err.println ("Exception stepRule: " + e.getMessage ());
    }
0 ?; j" x/ p. I8 a+ L/ a, H, |) `
* B. g# h; b4 C6 s: q    try {
3 e/ S1 L) \/ S      Heatbug proto = (Heatbug) heatbugList.get (0);
      Selector sel =
        new Selector (proto.getClass (), "heatbugStep", false);
, [. T) |2 ~# I9 }7 w      actionForEach =
        modelActions.createFActionForEachHomogeneous$call
        (heatbugList,
+ F* |- S+ _: @         new FCallImpl (this, proto, sel,
                        new FArgumentsImpl (this, sel)));
    } catch (Exception e) {
" t* P, }( `; v7 g3 y      e.printStackTrace (System.err);
) w4 u! z- h0 e) ]    }
6 o  I( M/ H- `5 z  W& {$ {5 H   
    syncUpdateOrder ();
; c1 I$ P5 M: m: w4 b* R
    try {
      modelActions.createActionTo$message
% Y0 g- D8 I) |7 i, P8 k9 l* f        (heat, new Selector (heat.getClass (), "updateLattice", false));
) A! e! V3 Y  n& ~; D    } catch (Exception e) {
! U1 ~. d2 G4 M9 c+ b. W3 r      System.err.println("Exception updateLattice: " + e.getMessage ());
    }
        
9 Q# k. \7 b& ]" L' j    // Then we create a schedule that executes the
    // modelActions. modelActions is an ActionGroup, by itself it
4 W  c4 n1 t+ A( M9 b+ B; @! X    // has no notion of time. In order to have it executed in
    // time, we create a Schedule that says to use the
    // modelActions ActionGroup at particular times.  This
    // schedule has a repeat interval of 1, it will loop every
    // time step.  The action is executed at time 0 relative to
3 D5 ]" ~* c  S+ q6 l6 V    // the beginning of the loop.

    // This is a simple schedule, with only one action that is
* I$ A. U9 s4 r    // just repeated every time. See jmousetrap for more
) i& J2 T, `) ^  q6 g    // complicated schedules.
2 N6 V- g8 x9 `; K- Z  
    modelSchedule = new ScheduleImpl (getZone (), 1);
    modelSchedule.at$createAction (0, modelActions);
1 x" b! p+ {1 I, c        
( I: S. Z0 J# W1 W    return this;
  }