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();
9 \  }2 |# }+ Y+ `! G9 W0 `   
    // Create the list of simulation actions. We put these in
( b3 ~. E* D% f- k) ]5 i    // 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
: ]" O9 ^1 P9 \5 Q2 G8 s. \! \2 @* ^    // object, or ForEach object in a collection.
        
    // Note we update the heatspace in two phases: first run
    // diffusion, then run "updateWorld" to actually enact the
    // changes the heatbugs have made. The ordering here is
4 W* f: L2 N7 t/ `    // significant!
        
4 u0 n5 R, r! Z; @: Z    // Note also, that with the additional
* n, t, }/ T' t" Y8 D6 X    // `randomizeHeatbugUpdateOrder' Boolean flag we can
  [7 l: B7 ]7 Y9 ]& e    // 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
0 t7 }, Y2 ?1 _% k    // list from timestep to timestep
( s9 A! e& `, F        
) O& b* L7 c3 P8 R8 e/ R4 V    // By default, all `createActionForEach' modelActions have
% m4 k. Y& a4 D2 ]" o    // a default order of `Sequential', which means that the
    // order of iteration through the `heatbugList' will be
" V8 a9 U9 N: A. C6 u  _    // identical (assuming the list order is not changed
3 c- x( p3 Y4 d; X; h    // indirectly by some other process).
   
    modelActions = new ActionGroupImpl (getZone ());

    try {
      modelActions.createActionTo$message
) y2 s4 k( J# u& F        (heat, new Selector (heat.getClass (), "stepRule", false));
+ Y+ {' ]  l+ P( E( r6 O1 R/ N& }    } catch (Exception e) {
6 n1 Y8 |1 S: X# w+ C) q1 I. L      System.err.println ("Exception stepRule: " + e.getMessage ());
    }

    try {
      Heatbug proto = (Heatbug) heatbugList.get (0);
+ _) P# B/ n) f0 v6 ^      Selector sel =
% O& h- u/ p6 I. G) C        new Selector (proto.getClass (), "heatbugStep", false);
      actionForEach =
7 s. ?# p+ q3 L9 M* d0 C9 c, S4 c! J        modelActions.createFActionForEachHomogeneous$call
        (heatbugList,
- Q5 X1 S  e. m# T' j3 l; w" M$ C% y         new FCallImpl (this, proto, sel,
1 Z$ T$ Z3 L( Q* ^/ z  G2 t                        new FArgumentsImpl (this, sel)));
1 G0 X% ^) W; w' R5 ^' ^- K    } catch (Exception e) {
2 R- ]+ O- _! ^) M& S4 ?6 z      e.printStackTrace (System.err);
    }
: }0 G2 l6 w2 N5 C$ r' n2 _   
    syncUpdateOrder ();

    try {
' _) T# q2 Q$ u; `& \      modelActions.createActionTo$message
1 `" E. f; }0 W9 \- G% l* [; @        (heat, new Selector (heat.getClass (), "updateLattice", false));
/ {) P6 z- J8 o! ~' {9 r7 w& x' [    } catch (Exception e) {
      System.err.println("Exception updateLattice: " + e.getMessage ());
    }
5 O$ o9 x% v. F* m. u/ B        
% t) E. I, ]  i5 J3 \4 L; C" @! s    // Then we create a schedule that executes the
    // modelActions. modelActions is an ActionGroup, by itself it
4 n/ \5 q, ^# E9 y0 P9 L; \    // has no notion of time. In order to have it executed in
, _# P: R+ u- t1 G. h% j7 D' k    // time, we create a Schedule that says to use the
. t* M# s: V& p$ u    // modelActions ActionGroup at particular times.  This
    // schedule has a repeat interval of 1, it will loop every
9 t8 u& ?: G2 C7 E& P  m% k( |( u4 i! Y    // time step.  The action is executed at time 0 relative to
    // the beginning of the loop.

- P4 P+ M3 m) t" }    // This is a simple schedule, with only one action that is
; S* c& P& Y5 E3 h. m7 @    // just repeated every time. See jmousetrap for more
    // complicated schedules.
% F1 O& j/ m. u8 F6 \9 ^  
    modelSchedule = new ScheduleImpl (getZone (), 1);
    modelSchedule.at$createAction (0, modelActions);
9 x; |  w" x% m% z        
! u% N  G. l! Z2 N2 w7 {3 ?9 z0 K% l. t    return this;
  }