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：

  V# D) T% u6 ?3 ?+ [: m! ` public Object buildActions () {
    super.buildActions();
   
1 Z5 k6 H3 `' C/ M, o7 F    // Create the list of simulation actions. We put these in
    // an action group, because we want these actions to be
4 E9 e' h( o# V    // 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
  r6 Q  m% ?& d( v: h7 i    // object, or ForEach object in a collection.
        
: ^: L: I% n  ]6 s    // Note we update the heatspace in two phases: first run
+ X$ S/ Q4 R) `8 E  O7 Z9 |    // diffusion, then run "updateWorld" to actually enact the
- E1 y: D5 L, t7 G: y9 C    // changes the heatbugs have made. The ordering here is
9 x$ [6 `! T5 C% _( X5 r: u    // significant!
        
    // Note also, that with the additional
    // `randomizeHeatbugUpdateOrder' Boolean flag we can
    // randomize the order in which the bugs actually run
( F$ B- E! q. t" o2 a    // their step rule.  This has the effect of removing any
    // systematic bias in the iteration throught the heatbug
    // list from timestep to timestep
        
    // By default, all `createActionForEach' modelActions have
    // a default order of `Sequential', which means that the
3 \- U$ J, ]$ k: e; B1 S    // order of iteration through the `heatbugList' will be
    // identical (assuming the list order is not changed
    // indirectly by some other process).
   
* ~. Q6 q$ t6 N- e    modelActions = new ActionGroupImpl (getZone ());

    try {
3 E$ G5 a6 l5 P. L4 l+ Z& D/ @: Z      modelActions.createActionTo$message
# G- _! H/ f! d        (heat, new Selector (heat.getClass (), "stepRule", false));
3 d" l4 ^( s0 W5 [0 @4 D$ @    } catch (Exception e) {
      System.err.println ("Exception stepRule: " + e.getMessage ());
    }
1 y( S& Z4 w) R' j1 W
    try {
5 ^* D. D7 x1 H* @" ]5 _# @      Heatbug proto = (Heatbug) heatbugList.get (0);
6 p9 Z+ w$ ?* ^, @8 p+ L      Selector sel =
        new Selector (proto.getClass (), "heatbugStep", false);
; _7 n8 Y2 M6 O3 e( y( c) r      actionForEach =
, u4 ?# N5 L) `+ a! p3 D9 ^        modelActions.createFActionForEachHomogeneous$call
        (heatbugList,
         new FCallImpl (this, proto, sel,
                        new FArgumentsImpl (this, sel)));
    } catch (Exception e) {
      e.printStackTrace (System.err);
' L- ]5 u& j- @. ^6 y; L( Y- R    }
   
    syncUpdateOrder ();

    try {
4 m/ e( b4 d% Z      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "updateLattice", false));
    } catch (Exception e) {
6 e; v5 z! P/ h. R      System.err.println("Exception updateLattice: " + e.getMessage ());
4 y& E+ U* q$ d# i" }    }
        
2 D4 _$ l3 v9 o9 n    // Then we create a schedule that executes the
# a  o4 W3 v& o* }/ _    // modelActions. modelActions is an ActionGroup, by itself it
2 J7 a; O$ {, ~: v3 n0 [6 x6 l    // 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
) |0 d2 C5 R3 q7 V0 A( p    // schedule has a repeat interval of 1, it will loop every
" |" f" h; Q& b/ v. p+ E, Z    // time step.  The action is executed at time 0 relative to
2 f& M3 J9 t' G3 o$ j) [& P4 [% s+ W1 P    // the beginning of the loop.
) z9 k5 e" D+ w' M) k! W/ j
    // This is a simple schedule, with only one action that is
) S' P- U0 @% B+ S$ Q8 F+ G- G$ O    // just repeated every time. See jmousetrap for more
    // complicated schedules.
  
    modelSchedule = new ScheduleImpl (getZone (), 1);
$ W1 w' n5 e! g/ S    modelSchedule.at$createAction (0, modelActions);
9 B' Y# G5 f* d0 t5 `/ g2 }        
3 ~0 f$ c: J! ]6 q    return this;
+ F/ \& Y2 ^7 `/ y  }