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：

public Object buildActions () {
    super.buildActions();
$ b/ A% I, n* \   
    // Create the list of simulation actions. We put these in
    // an action group, because we want these actions to be
6 E7 [/ D+ r+ N1 D1 U    // executed in a specific order, but these steps should
    // take no (simulated) time. The M(foo) means "The message
    // called <foo>". You can send a message To a particular
    // object, or ForEach object in a collection.
        
# y- m1 t' g4 h8 r) F    // Note we update the heatspace in two phases: first run
    // diffusion, then run "updateWorld" to actually enact the
    // changes the heatbugs have made. The ordering here is
% q% R# X# P+ n, b; R5 E    // significant!
        
    // Note also, that with the additional
    // `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
        
# H, P$ @6 w2 t5 P    // By default, all `createActionForEach' modelActions have
    // a default order of `Sequential', which means that the
- @+ n" H; X! C+ R( v; j! r2 f    // order of iteration through the `heatbugList' will be
  q3 s! J" [9 a* q+ H, X    // identical (assuming the list order is not changed
" d) X1 U; L& F3 C$ q    // indirectly by some other process).
% r3 `4 O8 |7 }6 }, S   
    modelActions = new ActionGroupImpl (getZone ());

    try {
% o1 W6 j; B( P1 t9 F; y      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "stepRule", false));
    } catch (Exception e) {
      System.err.println ("Exception stepRule: " + e.getMessage ());
6 j& u* l+ S2 Z/ P  q! s. y    }
8 g( L& V) w" }; ^. i: t4 h2 s) G
, ]. c+ [( N1 U( S0 v6 |! C0 v    try {
      Heatbug proto = (Heatbug) heatbugList.get (0);
      Selector sel =
; e) w) h$ S4 q5 a* U4 r$ k- e        new Selector (proto.getClass (), "heatbugStep", false);
      actionForEach =
        modelActions.createFActionForEachHomogeneous$call
        (heatbugList,
         new FCallImpl (this, proto, sel,
& k4 ^9 U' Y, [8 X6 q4 F  Z                        new FArgumentsImpl (this, sel)));
    } catch (Exception e) {
      e.printStackTrace (System.err);
    }
% I1 G3 ]& N4 K. s: T+ }   
    syncUpdateOrder ();
9 f# {& F. n2 e
+ j6 C' c8 ]5 W7 E    try {
. e; ^- x0 U+ [9 v$ x6 H      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "updateLattice", false));
    } catch (Exception e) {
      System.err.println("Exception updateLattice: " + e.getMessage ());
    }
& E( t8 [6 X( o/ P3 W        
" W1 y6 M% q+ v! }3 }- r    // Then we create a schedule that executes the
    // modelActions. modelActions is an ActionGroup, by itself it
$ j# p# |- R) W0 Y7 u  E' P    // has no notion of time. In order to have it executed in
* E5 p. ?) S. v    // time, we create a Schedule that says to use the
    // modelActions ActionGroup at particular times.  This
  q5 C+ ^3 S( n( N    // schedule has a repeat interval of 1, it will loop every
# x# O+ i0 Y- H* W6 Z5 ^; S; i    // time step.  The action is executed at time 0 relative to
$ R9 g/ _0 t7 H3 j    // the beginning of the loop.

+ M" l' y% u# _! e$ y0 w/ t    // This is a simple schedule, with only one action that is
    // just repeated every time. See jmousetrap for more
    // complicated schedules.
  
    modelSchedule = new ScheduleImpl (getZone (), 1);
" C) l- s( a, H' l- ~; v    modelSchedule.at$createAction (0, modelActions);
        
    return this;
  }