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
    // 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.
, A; @7 {# e" w4 |! ~/ h        
- m, f& S  M3 Q+ Q    // Note we update the heatspace in two phases: first run
2 t0 \4 i3 X: l3 C6 C    // diffusion, then run "updateWorld" to actually enact the
    // changes the heatbugs have made. The ordering here is
' B. x, A; x# c    // significant!
        
    // Note also, that with the additional
- n8 T; C2 |. o1 z0 A! z, w9 g( u    // `randomizeHeatbugUpdateOrder' Boolean flag we can
    // randomize the order in which the bugs actually run
7 Y8 P3 S  f) n  U8 u8 \    // their step rule.  This has the effect of removing any
    // systematic bias in the iteration throught the heatbug
# n! ~+ a+ c/ H  ]' ]    // list from timestep to timestep
        
0 d9 F6 W6 q7 J- l' X2 ]: U9 m    // By default, all `createActionForEach' modelActions have
    // 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).
   
    modelActions = new ActionGroupImpl (getZone ());
# m3 t: H2 f# f( F% l) V# j
8 A1 k7 p" A, X    try {
      modelActions.createActionTo$message
) @3 Y* T7 P. a. Y4 A3 J; w- ?        (heat, new Selector (heat.getClass (), "stepRule", false));
0 k+ S* C) h: b8 H+ K3 q+ }6 k" ^6 D    } catch (Exception e) {
" M' m1 u0 h6 F. C) L9 X      System.err.println ("Exception stepRule: " + e.getMessage ());
    }

# x$ `+ g- \1 a3 o: y    try {
& [: y  O& a% Z7 i5 T      Heatbug proto = (Heatbug) heatbugList.get (0);
9 w3 d+ p8 C% Z3 a; s6 J, }      Selector sel =
' [# u3 ?6 \- I3 S! }        new Selector (proto.getClass (), "heatbugStep", false);
6 {: N) i0 A# g* _# m      actionForEach =
" w7 _" U3 y9 q8 J! x" ?0 s6 u( _        modelActions.createFActionForEachHomogeneous$call
% Y7 C$ }+ F, F8 F: {        (heatbugList,
         new FCallImpl (this, proto, sel,
, j& r7 {$ _3 Z# ~$ b' u4 D. L                        new FArgumentsImpl (this, sel)));
    } catch (Exception e) {
8 H2 F" E" b  i- t      e.printStackTrace (System.err);
2 ]  o( B% F% y; s  A0 q* d. G: E    }
   
! X8 w% B! b6 A. Q$ {! I1 t- ~3 P    syncUpdateOrder ();

    try {
& F2 S  Z/ u! E2 D1 g" [" f      modelActions.createActionTo$message
! B' M, |* F, P        (heat, new Selector (heat.getClass (), "updateLattice", false));
7 T' }  S+ x5 N9 M& ?    } catch (Exception e) {
      System.err.println("Exception updateLattice: " + e.getMessage ());
    }
, \; S: c2 ~$ Y" D5 }        
; }1 K- V3 J9 X- x    // Then we create a schedule that executes the
+ X) F0 l- `: b: Q( x: V8 I    // modelActions. modelActions is an ActionGroup, by itself it
+ H6 H/ y4 k5 C$ W3 C# I, C    // 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
    // schedule has a repeat interval of 1, it will loop every
2 @0 S( E8 ?% F- ^+ j+ n  X1 y* Q    // 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
- S8 E- P: G+ h8 e: @3 o    // just repeated every time. See jmousetrap for more
    // complicated schedules.
. x4 q& @: R- x9 B  
    modelSchedule = new ScheduleImpl (getZone (), 1);
    modelSchedule.at$createAction (0, modelActions);
: i' O: a, h' Z6 o' p* V4 H2 I5 L0 {        
, I# V2 B8 n: m& A1 W, U    return this;
  }