Something odd just happened. I tried printing out the nested structure array as you suggested, and got some rather odd output (notice the three "null"s in a row):

ObjectPointAndOrientationStructure(allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes))) { ObjectPointStructure obj_pnt@0=ObjectPointStructure(allocated@0x31d9a38 (24 bytes)) { int obj_pnt_nbr@0=0 int fac_type_sys_nbr@4=0 int fac_enty_nbr@8=0 int rail_loca_nbr@c=0 byte obj_pnt_type_code[5]@10=[B@1a897a9 } int num_rpls@18=0 OrientationStructure ornt[3]@20=[Lcom.uprr.efm.nativ.struct.OrientationStructure;@17cec96 } null null null ObjectPointAndOrientationStructure(allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes))))) { ObjectPointStructure obj_pnt@0=ObjectPointStructure(allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes)))))) { int obj_pnt_nbr@0=0 int fac_type_sys_nbr@4=0 int fac_enty_nbr@8=0 int rail_loca_nbr@c=0 byte obj_pnt_type_code[5]@10=[B@90832e } int num_rpls@18=0 OrientationStructure ornt[3]@20=[Lcom.uprr.efm.nativ.struct.OrientationStructure;@1947496 } OrientationStructure(allocated@0x376c30 (264 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes)))))) { RailPathLocationStructure rpl@0=RailPathLocationStructure(allocated@0x376c30 (264 bytes) (shared from allocated@0x376c30 (264 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes))))))) { int rail_path_loca_nbr@0=0 int anlz_rail_loca_nbr@4=0 int ref_rail_loca_nbr@8=0 int rail_path_nbr@c=0 double mile_valu@10=0.0 double feet_from@18=0.0 double ecs@20=0.0 byte decn_pnt_dir[2]@28=[B@1724a9d byte mp_dir_ind@2a=0 } RopoStructure ropo@30=RopoStructure(allocated@0x376c60 (216 bytes) (shared from allocated@0x376c30 (264 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes))))))) { int rail_obj_pnt_nbr@0=0 int rail_path_loca_nbr@4=0 double segm_seq_nbr@8=0.0 byte segm_mile_post_dir@10=0 byte incr_decr_dir@11=0 OffsetStructure offset@14=OffsetStructure(allocated@0x376c74 (196 bytes) (shared from allocated@0x376c60 (216 bytes) (shared from allocated@0x376c30 (264 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes)))))))) { byte direction@0=0 NativeLong distance@4=0 } } double dist_from@50=0.0 } OrientationStructure(allocated@0x376c88 (176 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes)))))) { RailPathLocationStructure rpl@0=RailPathLocationStructure(allocated@0x376c88 (176 bytes) (shared from allocated@0x376c88 (176 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes))))))) { int rail_path_loca_nbr@0=0 int anlz_rail_loca_nbr@4=0 int ref_rail_loca_nbr@8=0 int rail_path_nbr@c=0 double mile_valu@10=0.0 double feet_from@18=0.0 double ecs@20=0.0 byte decn_pnt_dir[2]@28=[B@80cac9 byte mp_dir_ind@2a=0 } RopoStructure ropo@30=RopoStructure(allocated@0x376cb8 (128 bytes) (shared from allocated@0x376c88 (176 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes))))))) { int rail_obj_pnt_nbr@0=0 int rail_path_loca_nbr@4=0 double segm_seq_nbr@8=0.0 byte segm_mile_post_dir@10=0 byte incr_decr_dir@11=0 OffsetStructure offset@14=OffsetStructure(allocated@0x376ccc (108 bytes) (shared from allocated@0x376cb8 (128 bytes) (shared from allocated@0x376c88 (176 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes)))))))) { byte direction@0=0 NativeLong distance@4=0 } } double dist_from@50=0.0 } OrientationStructure(allocated@0x376ce0 (88 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes)))))) { RailPathLocationStructure rpl@0=RailPathLocationStructure(allocated@0x376ce0 (88 bytes) (shared from allocated@0x376ce0 (88 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes))))))) { int rail_path_loca_nbr@0=0 int anlz_rail_loca_nbr@4=0 int ref_rail_loca_nbr@8=0 int rail_path_nbr@c=0 double mile_valu@10=0.0 double feet_from@18=0.0 double ecs@20=0.0 byte decn_pnt_dir[2]@28=[B@18166e5 byte mp_dir_ind@2a=0 } RopoStructure ropo@30=RopoStructure(allocated@0x376d10 (40 bytes) (shared from allocated@0x376ce0 (88 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes))))))) { int rail_obj_pnt_nbr@0=0 int rail_path_loca_nbr@4=0 double segm_seq_nbr@8=0.0 byte segm_mile_post_dir@10=0 byte incr_decr_dir@11=0 OffsetStructure offset@14=OffsetStructure(allocated@0x376d24 (20 bytes) (shared from allocated@0x376d10 (40 bytes) (shared from allocated@0x376ce0 (88 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376c10 (296 bytes) (shared from allocated@0x376ae8 (592 bytes) (shared from allocated@0x376ae8 (592 bytes)))))))) { byte direction@0=0 NativeLong distance@4=0 } } double dist_from@50=0.0 } # # An unexpected error has been detected by HotSpot Virtual Machine: # # EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x03cdebf1, pid=4788, tid=656 # # Java VM: Java HotSpot(TM) Client VM (1.5.0_04-b05 mixed mode, sharing) # Problematic frame: # C [efms-api.dll+0x2ebf1] # # An error report file with more information is saved as hs_err_pid4788.log # # If you would like to submit a bug report, please visit: # http://java.sun.com/webapps/bugreport/crash.jsp # Connected to dev091 as dtns999 About to initialize SOP output array: 592 bytes starting at 1000E5A4.

Here's the code that generated the above output:

for (ObjectPointAndOrientationStructure entry : opos) { System.err.println(entry); for (OrientationStructure structure : entry.ornt) { System.err.println(structure); } }