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：

- y$ q, J$ p5 M% [3 `8 S( B/ ~ public Object buildActions () {
    super.buildActions();
4 o9 ?' t& i. W, m   
    // 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
) l' C8 N7 ?) |    // take no (simulated) time. The M(foo) means "The message
: X' v0 c: S3 F- E7 Z5 x7 x    // called <foo>". You can send a message To a particular
0 ?. M( j. v) G: w; G) p; g    // object, or ForEach object in a collection.
        
% A3 J  N* ~, f- V4 M2 M3 j8 q$ H    // 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
6 n- F+ p$ l* R9 H    // significant!
) K% r, R9 a* t+ G9 g        
    // Note also, that with the additional
    // `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
    // list from timestep to timestep
1 C" e6 b2 m+ g- }( d        
  y. Q7 L7 ~3 O6 ?0 q, k! {0 H    // By default, all `createActionForEach' modelActions have
    // a default order of `Sequential', which means that the
% `  k: I7 b9 y3 p5 C$ _  [9 w; g    // order of iteration through the `heatbugList' will be
4 x3 K* i( I* F/ `8 r4 P- T9 K    // identical (assuming the list order is not changed
( c8 p7 V6 F8 |3 _" H2 i9 S    // indirectly by some other process).
2 }. e% z$ ?! g9 M5 y9 m- {! R   
    modelActions = new ActionGroupImpl (getZone ());
% N) }" W! O- C9 e! `
    try {
6 U+ k/ Q. z5 p7 f/ B      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "stepRule", false));
    } catch (Exception e) {
      System.err.println ("Exception stepRule: " + e.getMessage ());
    }
. N9 r7 @( V, ]. [, Q% Q; Z8 P
# [7 Z% ~% r8 K( @    try {
      Heatbug proto = (Heatbug) heatbugList.get (0);
4 ~5 h3 K4 _. R( U: o      Selector sel =
+ r. M$ {: t, n' I2 m  N        new Selector (proto.getClass (), "heatbugStep", false);
0 L9 o/ m8 V" J3 t5 u1 x      actionForEach =
        modelActions.createFActionForEachHomogeneous$call
        (heatbugList,
         new FCallImpl (this, proto, sel,
' L% k+ g4 L* P. O7 O                        new FArgumentsImpl (this, sel)));
. W- Q# U2 D  ~" i$ q, U    } catch (Exception e) {
: o+ y5 J% ?+ u" J! a! F: p      e.printStackTrace (System.err);
3 v+ ]) |, H8 o9 Z4 M    }
/ H" ~3 G% A0 Q   
3 [  j) Z/ I, V    syncUpdateOrder ();

$ P/ V' p' t) J' w9 G    try {
  x9 X1 o" _* r8 k$ R) u      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "updateLattice", false));
5 u% v  p1 f7 r8 N1 A! c    } catch (Exception e) {
      System.err.println("Exception updateLattice: " + e.getMessage ());
* C; |5 r, z) `    }
        
    // Then we create a schedule that executes the
3 f2 d+ ?9 Z; h: H6 m    // modelActions. modelActions is an ActionGroup, by itself it
    // has no notion of time. In order to have it executed in
% a  x8 X3 e/ |; H6 L6 r5 \# m3 j, L    // time, we create a Schedule that says to use the
( Z' w; X! N& Z! a" V, r4 V    // modelActions ActionGroup at particular times.  This
- u7 x4 B/ x& A; X2 C& d, t5 a    // schedule has a repeat interval of 1, it will loop every
( E, v5 _5 S; w! u! V9 B" e) X    // time step.  The action is executed at time 0 relative to
6 U, T7 x2 b0 H6 o. @3 ~    // the beginning of the loop.

    // This is a simple schedule, with only one action that is
    // just repeated every time. See jmousetrap for more
    // complicated schedules.
7 g9 w* p: S8 h* X: ^7 _- a  
3 B7 a, q  j) ^. J" y" o2 j    modelSchedule = new ScheduleImpl (getZone (), 1);
    modelSchedule.at$createAction (0, modelActions);
        
% w3 N5 I( X+ m+ F' G1 U    return this;
# N8 K9 L& B! N$ {) g  }