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
    // an action group, because we want these actions to be
6 }5 e7 y: J9 A2 n1 ~7 B    // 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.
        
, {6 f( Q. g8 U2 R2 ^    // 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!
        
    // Note also, that with the additional
5 ~0 Z, M9 y8 v, t    // `randomizeHeatbugUpdateOrder' Boolean flag we can
    // randomize the order in which the bugs actually run
    // their step rule.  This has the effect of removing any
7 y9 s1 o: m6 {; p5 p# {0 Q    // systematic bias in the iteration throught the heatbug
, E& ^7 B! D" Q# O& ?$ W* |    // list from timestep to timestep
+ m1 p1 M+ p8 a) @" r        
1 ^& J4 h& x+ g- t4 W& L    // By default, all `createActionForEach' modelActions have
    // a default order of `Sequential', which means that the
3 r3 {1 u/ r+ R. p8 _    // order of iteration through the `heatbugList' will be
9 r& u: V/ h6 C: \& [! Q7 N    // identical (assuming the list order is not changed
8 V. O  d; Q# w4 C    // indirectly by some other process).
   
& I( w& Y- M2 Z    modelActions = new ActionGroupImpl (getZone ());

9 J; b: U) [, u    try {
# r9 r1 S$ \% p% M7 A# h+ B( V* d      modelActions.createActionTo$message
9 u/ }6 Y+ }9 b; f  B3 \        (heat, new Selector (heat.getClass (), "stepRule", false));
# ^2 m2 J5 K: _1 W3 s" d    } catch (Exception e) {
      System.err.println ("Exception stepRule: " + e.getMessage ());
    }

    try {
  K0 S9 N$ c2 j      Heatbug proto = (Heatbug) heatbugList.get (0);
      Selector sel =
' E$ b: U9 ~8 ~0 u5 L) d- S& D0 |: \        new Selector (proto.getClass (), "heatbugStep", false);
1 d" S$ v7 r4 @  x      actionForEach =
) }5 I2 _- u1 j; I& x: D& L$ r        modelActions.createFActionForEachHomogeneous$call
        (heatbugList,
# W$ U; ^5 F" e+ N; z0 i, ^8 I         new FCallImpl (this, proto, sel,
1 V. E/ E; b8 t& L% }                        new FArgumentsImpl (this, sel)));
    } catch (Exception e) {
9 y' n! q+ w- h      e.printStackTrace (System.err);
    }
   
! h, h# ^: r6 B7 d  ~' e    syncUpdateOrder ();

    try {
      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "updateLattice", false));
    } catch (Exception e) {
      System.err.println("Exception updateLattice: " + e.getMessage ());
3 |2 _$ v2 O) ?, R# q    }
        
    // Then we create a schedule that executes the
8 P9 {* L0 Y) l4 F    // 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
: h0 v/ t) a. H+ i7 p    // modelActions ActionGroup at particular times.  This
$ i' l# d+ b2 Q7 H    // 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.

" d9 c9 I2 C9 w2 z5 _+ Q- h    // This is a simple schedule, with only one action that is
9 W  O& M# f4 u1 T1 Z" P    // just repeated every time. See jmousetrap for more
/ l8 D& W7 s5 W; Y    // complicated schedules.
  
    modelSchedule = new ScheduleImpl (getZone (), 1);
7 y6 `. Q) Y% G9 M    modelSchedule.at$createAction (0, modelActions);
/ W8 z! W8 Y1 j+ h# K. Y$ i1 l$ T        
3 t1 J' x8 \6 ~% E    return this;
# ~9 x( u* ?8 j# K1 [  }