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
    // executed in a specific order, but these steps should
: z4 G. N) M$ B    // take no (simulated) time. The M(foo) means "The message
  S/ q+ q1 Z& L/ }/ P, Y    // called <foo>". You can send a message To a particular
    // object, or ForEach object in a collection.
% {8 x$ U7 p+ N+ e: R) a        
0 b& i0 p  o- g0 s    // Note we update the heatspace in two phases: first run
2 @1 H$ _4 K4 d' h/ {. s, g; s    // diffusion, then run "updateWorld" to actually enact the
    // changes the heatbugs have made. The ordering here is
    // significant!
        
    // Note also, that with the additional
! w# Y# ?0 H& k1 D+ C: G* |    // `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
5 J+ _' k4 u8 c+ r% f& A    // list from timestep to timestep
        
* _" G% x0 r! Q- M( ^    // By default, all `createActionForEach' modelActions have
" K. A  Y9 Y* H% H- R    // a default order of `Sequential', which means that the
8 C  B+ C9 b" Z1 Y+ h    // order of iteration through the `heatbugList' will be
    // identical (assuming the list order is not changed
    // indirectly by some other process).
   
    modelActions = new ActionGroupImpl (getZone ());
- g# z8 ]) A" i8 F% X6 m
    try {
      modelActions.createActionTo$message
# w2 x* ?! J* e; a1 f        (heat, new Selector (heat.getClass (), "stepRule", false));
    } catch (Exception e) {
      System.err.println ("Exception stepRule: " + e.getMessage ());
1 r# r  K" @2 I" b7 E' R    }

% y$ N5 ?; p! v4 n9 A    try {
      Heatbug proto = (Heatbug) heatbugList.get (0);
      Selector sel =
7 j  F# T) X% |  w        new Selector (proto.getClass (), "heatbugStep", false);
      actionForEach =
; }8 y4 h2 n: S  T/ {        modelActions.createFActionForEachHomogeneous$call
# ^# @, v2 j" Q  E# O3 l" P" H        (heatbugList,
# w  b" p, _8 Z* D' u* q3 H$ v! W9 i         new FCallImpl (this, proto, sel,
) W+ ~( T$ R' d                        new FArgumentsImpl (this, sel)));
    } catch (Exception e) {
7 {, |; O5 Y, Y: ~6 U; i  M      e.printStackTrace (System.err);
. c' |- ~( o+ W: w    }
# {* v. }& \2 R   
8 _$ S/ M3 `0 M5 B4 s    syncUpdateOrder ();
3 j% c+ ^+ g- g
    try {
5 _+ o3 g& [3 L! O# H% w      modelActions.createActionTo$message
0 s/ i5 Y3 \! z4 A, t0 w3 k( F# a        (heat, new Selector (heat.getClass (), "updateLattice", false));
    } catch (Exception e) {
      System.err.println("Exception updateLattice: " + e.getMessage ());
& U' E" d; k9 g    }
        
, O$ S- c+ U* G4 @3 P( c    // Then we create a schedule that executes the
    // modelActions. modelActions is an ActionGroup, by itself it
* V4 Y2 S5 L  W1 \' G    // has no notion of time. In order to have it executed in
. w: `* P" y  B& ^, \) h    // time, we create a Schedule that says to use the
) P% V$ P8 t& [    // modelActions ActionGroup at particular times.  This
    // 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.
9 {0 U; I$ x9 U9 Q* {
    // This is a simple schedule, with only one action that is
    // just repeated every time. See jmousetrap for more
    // complicated schedules.
3 c& x& L' A" B& a  A2 J  
! b: V+ Q- C  T$ ^# G& X% n  B    modelSchedule = new ScheduleImpl (getZone (), 1);
    modelSchedule.at$createAction (0, modelActions);
        
, z' k* o* a3 J( X- _# ?    return this;
  }