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();
   
    // Create the list of simulation actions. We put these in
$ ~, x2 V! g# b& F) L( X    // an action group, because we want these actions to be
    // executed in a specific order, but these steps should
4 o5 B! O/ N" r& s% m' O    // 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.
* M+ y% O, N% \) X$ q* R        
! b9 y$ h: ]+ `1 @, {    // Note we update the heatspace in two phases: first run
    // diffusion, then run "updateWorld" to actually enact the
+ {! q* D  }4 k5 `    // changes the heatbugs have made. The ordering here is
    // significant!
0 ?3 j$ N9 Y1 U1 ]; O8 @9 _# e$ e) v        
, g  i& {( |- l; e0 J    // Note also, that with the additional
    // `randomizeHeatbugUpdateOrder' Boolean flag we can
    // randomize the order in which the bugs actually run
+ i) u$ c: r7 a) m1 N+ D% X& C    // their step rule.  This has the effect of removing any
* L# P& ]; T8 V& Y' k    // systematic bias in the iteration throught the heatbug
8 P/ B! g! Z% e: _% t2 M1 v0 [$ G& U. ~    // list from timestep to timestep
        
* ^) X% Y' I6 s) Q. R" i/ ^+ ^    // By default, all `createActionForEach' modelActions have
    // a default order of `Sequential', which means that the
. ]7 k& O( |) n& K  G) X; p    // order of iteration through the `heatbugList' will be
- H* }$ F+ ?$ }! W# O) p" \    // identical (assuming the list order is not changed
( H& I7 l; b, H# M! L    // indirectly by some other process).
   
    modelActions = new ActionGroupImpl (getZone ());

    try {
9 M5 x( g: z) S9 C3 Y3 i- Y: x% `      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "stepRule", false));
    } catch (Exception e) {
      System.err.println ("Exception stepRule: " + e.getMessage ());
    }

3 ]: C7 ~8 j  j; r& H0 L    try {
2 C/ Q5 g; I) G3 D: ?8 B      Heatbug proto = (Heatbug) heatbugList.get (0);
" X% j. x8 c* u5 M      Selector sel =
        new Selector (proto.getClass (), "heatbugStep", false);
      actionForEach =
        modelActions.createFActionForEachHomogeneous$call
( Y6 W, D; k5 i! X- J& Q; h% @        (heatbugList,
% X, w! v% q& y9 J  ^         new FCallImpl (this, proto, sel,
1 o1 P* O0 B6 h. k3 p                        new FArgumentsImpl (this, sel)));
    } catch (Exception e) {
0 x6 x* O: t6 z: B" \, a      e.printStackTrace (System.err);
    }
   
- B/ d. F% d9 V; F' i6 B. E% @+ g    syncUpdateOrder ();
1 ~% v- U' j# P  s3 ?
    try {
      modelActions.createActionTo$message
+ \; @' |0 L$ V9 m% J+ Y. ]( n) F        (heat, new Selector (heat.getClass (), "updateLattice", false));
    } catch (Exception e) {
      System.err.println("Exception updateLattice: " + e.getMessage ());
    }
        
& ^! p' l" h$ C& F# ]# P) F    // Then we create a schedule that executes the
    // modelActions. modelActions is an ActionGroup, by itself it
9 o* {/ g) R4 q    // has no notion of time. In order to have it executed in
4 }5 R0 ?* B! {3 s3 U5 S9 d8 A" `" o    // 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
# ?7 u. w0 [: o" Z/ ~- Y6 e# `  p    // time step.  The action is executed at time 0 relative to
    // the beginning of the loop.

    // This is a simple schedule, with only one action that is
    // just repeated every time. See jmousetrap for more
6 x9 y, v- M. i9 ~! [5 M    // complicated schedules.
1 I; v, u: [  Y8 G& E" B6 g8 q  
% k3 _! F+ I  }& R- Z. Q    modelSchedule = new ScheduleImpl (getZone (), 1);
    modelSchedule.at$createAction (0, modelActions);
        
$ v: e1 [7 E( j5 j1 e    return this;
  }