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：

% [* g( L: T: Z; T4 W% Y8 W1 i public Object buildActions () {
    super.buildActions();
/ u- M* O5 U6 l- p$ P2 j* |3 l& p   
    // Create the list of simulation actions. We put these in
2 E, q3 v, I& ~# d    // 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
. ?' r: m* V  i& S* e    // called <foo>". You can send a message To a particular
    // object, or ForEach object in a collection.
        
    // 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
    // significant!
        
4 L( i+ r3 z  S    // Note also, that with the additional
    // `randomizeHeatbugUpdateOrder' Boolean flag we can
+ f( v; \- R8 B4 x+ U, I8 [    // randomize the order in which the bugs actually run
/ t) [0 |; N. F2 D( F    // their step rule.  This has the effect of removing any
    // systematic bias in the iteration throught the heatbug
    // list from timestep to timestep
        
    // By default, all `createActionForEach' modelActions have
    // a default order of `Sequential', which means that the
. }0 }8 J  m' S: x7 \    // order of iteration through the `heatbugList' will be
3 t* N) N. o" p' ^    // identical (assuming the list order is not changed
    // indirectly by some other process).
   
/ l3 A" z+ m4 |# G" ?2 X0 ~    modelActions = new ActionGroupImpl (getZone ());
. o# ?$ q4 H( G2 S* k4 J. R' A4 }# P2 i
; e' p& y$ C- R/ t1 X1 K    try {
; [/ V2 D# r9 K1 ]& E      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "stepRule", false));
    } catch (Exception e) {
& k7 g% N# v, A      System.err.println ("Exception stepRule: " + e.getMessage ());
0 F5 A' z' v2 M- x5 l$ G    }
  Q$ L; k3 a" {4 X: S
; Z$ X2 j, G+ G, P- Y0 l0 h$ {    try {
      Heatbug proto = (Heatbug) heatbugList.get (0);
0 ?0 F. f. ~$ Y2 D6 K3 `      Selector sel =
6 @5 Q8 y: p5 i/ z* \        new Selector (proto.getClass (), "heatbugStep", false);
/ M8 ^3 r6 d3 R) Y9 b/ a, _      actionForEach =
) ]) z5 y3 C* C2 I        modelActions.createFActionForEachHomogeneous$call
) F/ B) G/ O% G        (heatbugList,
6 j) M: C- ]9 F) e' }         new FCallImpl (this, proto, sel,
                        new FArgumentsImpl (this, sel)));
+ |  O9 r% ?3 @& K1 F    } catch (Exception e) {
      e.printStackTrace (System.err);
; m# Y0 I; D' `( I1 Y    }
# b4 c5 c5 I" C. t$ ?8 {   
1 b. z  }% B; \8 d    syncUpdateOrder ();
1 n$ Y0 j8 ^' o7 f8 q( D/ @/ j1 b
    try {
3 ?: R8 g- J( m& v0 Z* Y      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "updateLattice", false));
    } catch (Exception e) {
2 o3 D) C' H' d      System.err.println("Exception updateLattice: " + e.getMessage ());
    }
        
    // Then we create a schedule that executes the
- e# p, f( m1 g, ?    // 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
" n5 j, V) Q1 D( T, f, \    // modelActions ActionGroup at particular times.  This
" h% t- H. n9 C3 q3 N    // schedule has a repeat interval of 1, it will loop every
    // time step.  The action is executed at time 0 relative to
    // the beginning of the loop.
- \5 H0 l% I- N
    // This is a simple schedule, with only one action that is
1 O/ T6 m; n. J    // just repeated every time. See jmousetrap for more
5 U, S; h8 m! o    // complicated schedules.
  
6 i  f: w9 x, \    modelSchedule = new ScheduleImpl (getZone (), 1);
    modelSchedule.at$createAction (0, modelActions);
        
" O7 J. p$ z1 c9 g& j0 N    return this;
+ E5 N2 [3 ]# d: \7 E; R6 Y  }