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 () {
) F# D7 V9 N/ g    super.buildActions();
( \1 G! u& Z( U: U* x   
' `$ a0 }) p" O    // 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
7 V1 E& L0 s4 A1 }  K: q- o* e/ g( ]    // 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.
6 M" @. V/ ?' Y; s: i- M        
9 J) W- }# A* o1 g+ ]) M/ G, q    // Note we update the heatspace in two phases: first run
    // diffusion, then run "updateWorld" to actually enact the
: u5 R9 \) q+ d. ?$ `: `" J    // changes the heatbugs have made. The ordering here is
# W& S% O2 U5 p, L) [" E* G    // significant!
# k6 Z7 Z" L$ ^$ f  A        
3 b/ n9 ?6 l, r# ?5 i4 j    // 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
! N$ g. O! n; Q- F9 I7 [    // list from timestep to timestep
% f) A" T6 u1 K0 C+ M# e        
, D& n1 `# E7 k6 {" m    // By default, all `createActionForEach' modelActions have
, ~' q$ o+ h& P. H/ B* z/ i    // 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).
& d9 @( B6 b- _" n; U   
    modelActions = new ActionGroupImpl (getZone ());

* t6 }! R- N) }% \1 a6 T    try {
4 B$ Q/ f6 \0 d3 \& H/ I* S      modelActions.createActionTo$message
) ?/ Q" u1 c3 C: s        (heat, new Selector (heat.getClass (), "stepRule", false));
    } catch (Exception e) {
      System.err.println ("Exception stepRule: " + e.getMessage ());
    }

/ K5 _4 S, l* [9 p# K1 o    try {
      Heatbug proto = (Heatbug) heatbugList.get (0);
) I$ ~* ~) k/ r      Selector sel =
        new Selector (proto.getClass (), "heatbugStep", false);
      actionForEach =
        modelActions.createFActionForEachHomogeneous$call
        (heatbugList,
2 u# a, p+ j3 l, j         new FCallImpl (this, proto, sel,
& W$ v: O& Y4 L4 e9 l                        new FArgumentsImpl (this, sel)));
% o# e6 M1 t5 s+ a) a    } catch (Exception e) {
/ J- }5 C0 V0 f      e.printStackTrace (System.err);
" A3 [$ G  ?  X3 r+ A5 d) p5 a    }
' {- B; h5 ~& w  Z6 |" ~) `  z3 d) S   
3 }$ L$ ^0 N5 b) D  m4 |4 I7 [- M& m    syncUpdateOrder ();

    try {
8 B5 f& j2 J. I7 {* h: ^      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "updateLattice", false));
    } catch (Exception e) {
      System.err.println("Exception updateLattice: " + e.getMessage ());
    }
        
. f; [' [8 ]/ b1 p9 O9 n% R, P5 R    // 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
    // modelActions ActionGroup at particular times.  This
% n( H+ |  T8 Z& i  `" U3 ]# d. f    // schedule has a repeat interval of 1, it will loop every
+ g. G" V; K9 o0 x  X- n& R    // time step.  The action is executed at time 0 relative to
1 C7 K1 L8 q& S* j8 Y) \    // the beginning of the loop.

; d0 c9 O+ M6 }2 Q3 U/ }    // This is a simple schedule, with only one action that is
, {6 f, X2 y. V. W% }0 `! k    // just repeated every time. See jmousetrap for more
    // complicated schedules.
3 q5 e. A, X- Z& P4 O  
    modelSchedule = new ScheduleImpl (getZone (), 1);
' p  O8 G8 h0 ~" u- J9 V. o    modelSchedule.at$createAction (0, modelActions);
) O7 H5 m( W. ]3 D' K        
    return this;
' [$ Z" W2 w) @+ @' r4 W2 y/ C  }