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 () {
0 ^; Z1 g. C2 k* y& o  I) @    super.buildActions();
+ F* q( }! z% S0 }   
    // 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
) G* f2 E# H9 w7 @7 b6 y, B; p( e    // 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.
2 ]/ w! p* S& J8 M2 Y" m+ j        
8 g3 `! T$ g% K# w- L1 s: w9 j8 _    // Note we update the heatspace in two phases: first run
3 c+ V/ a* _- L1 e- R    // diffusion, then run "updateWorld" to actually enact the
, f' G4 n. |! o% M- r* o" N    // changes the heatbugs have made. The ordering here is
    // significant!
, b0 r& j1 M3 E4 c0 H/ {        
: h& }, u! K3 A& Y    // Note also, that with the additional
0 l* v: R6 }5 x9 H    // `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
/ U; T8 B0 D; W) D" d  C' l+ ]    // list from timestep to timestep
# q+ ?5 H# H3 g# W' O! h4 W! c$ b9 X2 j        
5 S  S# @: r1 ~% M1 g    // By default, all `createActionForEach' modelActions have
6 q  B' @3 A5 U9 o    // a default order of `Sequential', which means that the
    // order of iteration through the `heatbugList' will be
: Q  `/ [7 J8 x" e" |    // identical (assuming the list order is not changed
    // indirectly by some other process).
   
: [  ]  o$ V  b- @    modelActions = new ActionGroupImpl (getZone ());

    try {
6 C( d; f: P0 ^! A7 W- H; [      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "stepRule", false));
    } catch (Exception e) {
) t( Y1 y* v2 |4 @      System.err.println ("Exception stepRule: " + e.getMessage ());
4 o3 S. f# g. O) L% F6 b    }

    try {
7 o+ p. i$ s# o0 u      Heatbug proto = (Heatbug) heatbugList.get (0);
      Selector sel =
        new Selector (proto.getClass (), "heatbugStep", false);
      actionForEach =
6 T0 o; J6 n9 v        modelActions.createFActionForEachHomogeneous$call
        (heatbugList,
! H% D& f2 E0 ?  d* I7 J( C         new FCallImpl (this, proto, sel,
6 v9 D1 R  v( f) }                        new FArgumentsImpl (this, sel)));
. y4 r/ C  G( `4 u2 x/ F& E! R) d    } catch (Exception e) {
" |. \* Q& A/ w( Y      e.printStackTrace (System.err);
0 t3 P8 `5 z- @& Q- }2 o    }
   
    syncUpdateOrder ();
) H. i' I9 q) I) O& f7 `
    try {
2 v( v( v& ^+ Z6 W$ w4 G      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "updateLattice", false));
7 t+ R: f- X: r0 r8 D* ^) e    } catch (Exception e) {
3 t3 S0 W  D2 m      System.err.println("Exception updateLattice: " + e.getMessage ());
) u! o1 A8 S# S/ c# S4 S" e    }
* `& G% Q' E7 A0 A2 W        
    // Then we create a schedule that executes the
# J, k9 a8 g% w) Y; D7 q0 U5 z    // modelActions. modelActions is an ActionGroup, by itself it
6 E2 k' ?9 n# k! u/ ^- c' r6 q    // has no notion of time. In order to have it executed in
    // time, we create a Schedule that says to use the
. q0 I! U- O6 b    // modelActions ActionGroup at particular times.  This
, Q) O8 J' l6 j( X& F    // schedule has a repeat interval of 1, it will loop every
    // time step.  The action is executed at time 0 relative to
    // the beginning of the loop.
7 {* L# Z$ S# p  j/ P$ C2 x2 `
    // This is a simple schedule, with only one action that is
    // just repeated every time. See jmousetrap for more
    // complicated schedules.
% v: X9 k& ^* p  
    modelSchedule = new ScheduleImpl (getZone (), 1);
: f8 f* B6 K* X& {    modelSchedule.at$createAction (0, modelActions);
        
    return this;
  }