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：

; O  e% q4 R5 |% [- ?5 g public Object buildActions () {
    super.buildActions();
   
    // Create the list of simulation actions. We put these in
    // an action group, because we want these actions to be
    // executed in a specific order, but these steps should
    // take no (simulated) time. The M(foo) means "The message
5 y: e" R  z& Y6 @    // called <foo>". You can send a message To a particular
    // object, or ForEach object in a collection.
        
3 @) q- @) e/ O9 a! E( `    // Note we update the heatspace in two phases: first run
    // diffusion, then run "updateWorld" to actually enact the
) B: W# R7 t, ?; D, v    // changes the heatbugs have made. The ordering here is
% ]0 q" O& ^, m* Z    // significant!
        
    // Note also, that with the additional
& k- Y$ I3 S2 a: }    // `randomizeHeatbugUpdateOrder' Boolean flag we can
) m; I+ \2 S/ M    // 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
- Z) v9 Y) d) \6 r9 J5 }& g+ X& i        
    // By default, all `createActionForEach' modelActions have
    // a default order of `Sequential', which means that the
    // order of iteration through the `heatbugList' will be
    // identical (assuming the list order is not changed
    // indirectly by some other process).
   
- L. f8 P" x" k    modelActions = new ActionGroupImpl (getZone ());

7 d% e& f! n: u2 F3 X: `* f( u- U; A( X    try {
# ~) ]+ ?. e4 ~( ?      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "stepRule", false));
    } catch (Exception e) {
      System.err.println ("Exception stepRule: " + e.getMessage ());
    }

    try {
7 Y8 @3 r0 s- P; p4 ^5 w      Heatbug proto = (Heatbug) heatbugList.get (0);
% P# v% e9 J& K      Selector sel =
3 J  V0 e3 ^# u, A& s# s2 _        new Selector (proto.getClass (), "heatbugStep", false);
      actionForEach =
        modelActions.createFActionForEachHomogeneous$call
        (heatbugList,
         new FCallImpl (this, proto, sel,
5 A9 l- l$ \6 ]4 v                        new FArgumentsImpl (this, sel)));
5 P: Y  I! d' ~3 ^3 t& z) n    } catch (Exception e) {
      e.printStackTrace (System.err);
% q: x6 x- Z; I, U' z# H  }) s    }
   
    syncUpdateOrder ();
) R1 N& G( A: A
    try {
3 F1 c" T, }: |- }- d1 i      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "updateLattice", false));
  v+ v$ I7 ?8 r4 g* R8 r    } catch (Exception e) {
* Q+ _9 c% A( m' \0 e5 v      System.err.println("Exception updateLattice: " + e.getMessage ());
: E. l: p7 d. Q( N( M' `    }
        
& H/ k+ Z$ V  }" @1 ]# n0 C. X( H    // Then we create a schedule that executes the
    // modelActions. modelActions is an ActionGroup, by itself it
    // has no notion of time. In order to have it executed in
    // time, we create a Schedule that says to use the
/ A  m% p1 X: x  t( N) o; d    // modelActions ActionGroup at particular times.  This
. M) g4 d4 ^: |- [) Q    // schedule has a repeat interval of 1, it will loop every
$ Y1 j' c7 J% m8 Y+ q& x5 s' s5 E$ @7 F    // time step.  The action is executed at time 0 relative to
    // the beginning of the loop.
3 J$ W' r  n$ V9 `. o, B) q
& F8 L3 U2 {- }! D8 A) V    // This is a simple schedule, with only one action that is
    // just repeated every time. See jmousetrap for more
" k. L4 u) g4 V: ~& r    // complicated schedules.
  
    modelSchedule = new ScheduleImpl (getZone (), 1);
5 P6 R6 }# y9 Q" X! _0 U2 A) D    modelSchedule.at$createAction (0, modelActions);
        
: X! |+ a& B7 F. y4 n    return this;
' Q6 ^# K& \$ E1 d: o7 C  }