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：

4 ^" A% Z) a' [. W  ^ 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.
        
    // Note we update the heatspace in two phases: first run
& N( E+ v5 y7 m- l    // diffusion, then run "updateWorld" to actually enact the
    // changes the heatbugs have made. The ordering here is
7 _& D5 x/ K: [# o4 X1 }    // significant!
        
    // Note also, that with the additional
/ L  v" y: `) s2 O2 {    // `randomizeHeatbugUpdateOrder' Boolean flag we can
' J3 u4 Y8 E3 a) p3 X- ]    // 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
' |- p3 k, T. {7 {- M7 q    // list from timestep to timestep
        
    // By default, all `createActionForEach' modelActions have
    // a default order of `Sequential', which means that the
/ r( ^/ a2 q# v8 s; I    // order of iteration through the `heatbugList' will be
    // identical (assuming the list order is not changed
* y4 Y. o+ O( [  s" J" D    // indirectly by some other process).
/ A/ U2 l- v5 r8 F( A# x9 N8 o8 d6 N   
    modelActions = new ActionGroupImpl (getZone ());
$ O: `5 J- U) V/ ^
5 D5 g# h- I: }) T$ W: _. E    try {
      modelActions.createActionTo$message
& i! q6 ]0 W8 i4 [5 U0 j        (heat, new Selector (heat.getClass (), "stepRule", false));
    } catch (Exception e) {
* w  P0 E/ h4 M" W8 N, |      System.err.println ("Exception stepRule: " + e.getMessage ());
    }
8 _5 p& K# q* A2 {
; e  J( }  U2 W    try {
4 H9 D  N7 |. R: l( j      Heatbug proto = (Heatbug) heatbugList.get (0);
      Selector sel =
        new Selector (proto.getClass (), "heatbugStep", false);
6 u7 P) p; k4 a' R) n/ z      actionForEach =
        modelActions.createFActionForEachHomogeneous$call
* ], |: R) G* @( ^/ O" E( d        (heatbugList,
5 M0 [1 T- ]$ z  A$ p( m3 X- B         new FCallImpl (this, proto, sel,
# a2 y3 w$ m& ]9 g4 Z                        new FArgumentsImpl (this, sel)));
; Q2 D: [, Z* J- ]5 m    } catch (Exception e) {
      e.printStackTrace (System.err);
    }
   
8 ?8 t1 n- w4 i. B$ A    syncUpdateOrder ();
5 i5 T3 p0 g) ~1 r% j
4 i8 b1 b/ z0 S2 K9 N    try {
      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "updateLattice", false));
/ R. ]6 \  H/ A* m* A. s% M! t  P    } catch (Exception e) {
      System.err.println("Exception updateLattice: " + e.getMessage ());
    }
  u+ R$ a: {% |( n" p- t& _/ K        
+ K& b3 p2 \" L; g3 I    // Then we create a schedule that executes the
    // modelActions. modelActions is an ActionGroup, by itself it
$ t4 Q$ ^* S5 `1 l, U8 C/ Y    // has no notion of time. In order to have it executed in
    // time, we create a Schedule that says to use the
: `0 Z" H0 q0 J( V, s4 w. M    // 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.

    // This is a simple schedule, with only one action that is
1 T4 w# R: _0 W7 @    // just repeated every time. See jmousetrap for more
    // complicated schedules.
$ H; K5 }9 l) A9 T0 f  
    modelSchedule = new ScheduleImpl (getZone (), 1);
$ f0 r1 A' G  O5 m    modelSchedule.at$createAction (0, modelActions);
& Q  n: g0 `, f! ]; N" r$ p        
) y, g% C0 t9 a5 `8 Q* a    return this;
% L# J5 ~. \. ?3 O8 W. F  }