Thanks for the comments. Let me chew on this one a little while and then I'll probably have something to add.
SS On 7/11/07, Michaël Michaud <[EMAIL PROTECTED]> wrote: > Hi, > > ID is not only unique for a layer, it is unique for all the features > derived from AbstractBasicFeature (mainly BasicFeature). > Note : when you connect to a database in such a way that data is only > loaded on demand, the same feature can take successively different ids > each time it is reloaded. > Some plugins may have there own implementation of Feature and manage id > differently. > > Michaël > > Sunburned Surveyor a écrit : > > >Stefan wrote: "the ID should be unique within one layer..." > > > >That is what I thought. Thank you for confirming. > > > >Stefan wrote: "for cloning and copying look in the code!" > > > >Actually, the getID method is defined in the Feature interface, and is > >implemented by BasicFeature. I think this leaves open some room for > >problems. Although our interface specifies the basic behavior of the > >getID method, it doesn't really specify the details of the mechanism > >used to identify Feature objects. Even if I look at the behavior of > >copying and cloning in the BasicFeeature implementation, it is > >possible that my FeatureCache might have to deal with implementations > >that do not use the same behavior. > > > >I will have to think about this problem some more. Perhaps I am > >missing something. > > > >Thanks for the suggestions. > > > >The Sunburned Surveyor > > > > > > > >On 7/8/07, Stefan Steiniger <[EMAIL PROTECTED]> wrote: > > > > > >>the ID should be unique within one layer.. > >> > >>for cloning and copying look in the code! > >> > >>Sunburned Surveyor schrieb: > >> > >> > >>>I'm still chipping away at my FeatureCache. I'm currently working on > >>>the class that will write Features to a binary file that uses a > >>>shortened format of BOFF. > >>>(http://thejumppilotproject.pbwiki.com/Binary+Open+Feature+Format) > >>>Part of the format stores a unique numeric identifier for the Feature, > >>>which I will also be using in my FeatureCache internally. > >>> > >>>The BOFF format defines this unique numeric identifier for features as > >>>an 8 byte long. The Feature interface provides a getID method that > >>>returns an int. This isn't a problem, since I Java will automatically > >>>convert the int to a long. > >>> > >>>However, I need to ask some questions about the getID method so that I > >>>don't use it improperly in the guts of the FeatureCache. Is the int > >>>returned by the getID method gauranteed to be unique within each > >>>FeatureCollection? Can a Layer contain two Features with the same ID? > >>>What if a Feature is cloned or copied? > >>> > >>>Thanks for any information on how the ID mechanism for Features works > >>>in JUMP/OpenJUMP. > >>> > >>>The Sunburned Surveyor > >>> > >>>------------------------------------------------------------------------- > >>>This SF.net email is sponsored by DB2 Express > >>>Download DB2 Express C - the FREE version of DB2 express and take > >>>control of your XML. No limits. Just data. Click to get it now. > >>>http://sourceforge.net/powerbar/db2/ > >>>_______________________________________________ > >>>Jump-pilot-devel mailing list > >>>Jump-pilot-devel@lists.sourceforge.net > >>>https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > >>> > >>> > >>> > >>> > >>------------------------------------------------------------------------- > >>This SF.net email is sponsored by DB2 Express > >>Download DB2 Express C - the FREE version of DB2 express and take > >>control of your XML. No limits. Just data. Click to get it now. > >>http://sourceforge.net/powerbar/db2/ > >>_______________________________________________ > >>Jump-pilot-devel mailing list > >>Jump-pilot-devel@lists.sourceforge.net > >>https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > >> > >> > >> > > > >------------------------------------------------------------------------- > >This SF.net email is sponsored by DB2 Express > >Download DB2 Express C - the FREE version of DB2 express and take > >control of your XML. No limits. Just data. 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