Method and apparatus for managing classfiles on devices without a file system

• US 6,366,898 B2
• Filed: 09/21/1998
• Issued: 04/02/2002
• Est. Priority Date: 09/21/1998
• Status: Expired due to Term

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Bush, William, Taivalsaari, Antero
• Primary Examiner(s): Alam, Hosain T.
• Assistant Examiner(s): Ly, Anh
• Application Number:
  US09/158,121
• Publication Number:
  US 20010044790A1
• Time in Patent Office: 1,289 Days
• Field of Search: 707/1, 707/7, 707/103, 707/206, 709/227, 709/247, 709/219, 713/200, 395/704, 395/705
• US Class Current: 1/1
• CPC Class Codes: G06F 9/445 Program loading or initiating bootstrapping G06F9/4401; security arrangements for program loading or initiating G06F21/57
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99937 Sorting

Abstract

The invention provides a method of creating and periodically loading a database of classfiles on a non traditional computer device, such as a PDA (personal digital assistant), cellular telephone, pager, appliances, or other embedded device. A resident Java virtual machine loads classes from this database instead of loading them from a file system. The embedded device is periodically updated by connecting it to a network or computer that includes a classfile source. At this time, records can be added to, or deleted from, the database (where the records are classfiles). The management of the classfile database on the embedded device is independent of the virtual machine on the embedded device. One embodiment of the invention comprises an embedded device with a virtual machine, a classfile database, a database manager, and a remote database loader. The embedded device and virtual machine can function even when not connected to the classfile source.

Claims

1. An apparatus comprising:

an embedded device containing a virtual machine, wherein said embedded device operates without file system;

a database on said embedded device for storing at least one classfile said virtual machine loading a required classfile for execution from said database;

a connector for coupling said embedded device to a classfile source for selectively downloading said at least one classfile from said classfile source into said database, wherein said classfile source is external to said embedded device, wherein said coupling and said downloading occurs if said required classfile is not one of said at least one classfile in said database.

2. The apparatus of claim 1 wherein said classfile source comprises a host computer system.

3. The apparatus of claim 1 wherein said connector communicates with said classfile source by carrier wave.

4. The apparatus of claim 1 wherein said connector communicates with said classfile source via a hard-wired connection.

5. The apparatus of claim 1 further including an application manager on said embedded device for identifying said at least one classfile to be downloaded from said classfile source.

6. The apparatus of claim 1 wherein said embedded device comprises a personal digital assistant.

7. The apparatus of claim 1 wherein said at least one classfile comprises bytecodes of a platform independent programming language.

8. The apparatus of claim 7 wherein said independent programming language comprises Java programming language.

9. The apparatus of claim 1 wherein said downloading of said at least one classfile is accomplished using a synching operation.

10. An apparatus comprising:

a classfile source;

an embedded device operating without a file system, wherein said embedded device is periodically synchronized during a synching operation via a temporary communications link to said classfile source, said communications link having a physical link that is periodically in connection with said classfile source;

a virtual machine executing in said embedded device;

a database of at least one classfile integrally located in said embedded device;

an applications manager in said embedded device for identifying said at least one classfile to be loaded into said database during said synching operation, said applications manager providing one or more required classfiles from said database for execution by said virtual machine, wherein said at least one classfile to be loaded is said one or more required classfiles not in said database.

11. The apparatus of claim 10 wherein said classfile source is available on a network.

12. The apparatus of claim 10 wherein said communications link is accomplished via carrier wave.

13. The apparatus of claim 10 wherein said at least one classfile comprises a platform independent programming language classfile.

14. The apparatus of claim 13 wherein said platform independent programming language comprises Java programming language.

15. The apparatus of claim 11 wherein said network comprises at least one host computer and said classfile source resides on said host computer.

16. The apparatus of claim 10 wherein said embedded device comprises a personal digital assistant.

17. A method of providing at least one classfile on an embedded device comprising:

providing a virtual machine in an embedded device, wherein said embedded device operates without a file system;

providing a database in said embedded device for storing at least one classfile for execution by said virtual machine, said virtual machine loading a required classfile for execution from said database;

connecting means for temporarily coupling said embedded device to a classfile source for selectively downloading said at least one classfile from said classfile source into said database, said connecting means having a connector that allows said embedded device to communicates with said classfile source, wherein said classfile source is external to said embedded device, said coupling and said downloading occurring if said required classfile is not one of said at least one classfile in said database.

18. The method of claim 17 wherein said classfile source comprises a host computer system.

19. The method of claim 17 wherein said connector communicates with said classfile source by carrier wave.

20. The method of claim 17 wherein said connector communicates with said classfile source via a hard wired connection.

21. The method of claim 17 further including providing an application manager on said embedded device for identifying said at least one classfile to be downloaded from said classfile source.

22. The method of claim 17 wherein said embedded device comprises a personal digital assistant.

23. The method of claim 17 wherein said at least one classfile comprises bytecodes of a platform independent programming language.

24. The method of claim 23 wherein said independent programming language comprises Java programming language.

25. The method of claim 17 wherein said downloading of said at least one classfile is accomplished using a synching operation.

26. A method of providing at least one classfile on an embedded device comprising:

providing a classfile source;

periodically synchronizing an embedded device using a synching operation via a temporary communications link to said classfile source, wherein said classfile source is external to said embedded device, said communications link having a physical link periodically in connection with said classfile source, wherein said embedded device operates with a file system;

providing a virtual machine executing in said embedded device;

providing a database of at least one classfile integrally located in said embedded device;

identifying at least one classfile to be loaded into said database during said synching operation using an applications manager in said embedded device;

providing one or more required classfiles from said database for executing by said virtual machine, wherein said at least one classfile to be loaded is said one or more required classfile not in said database.

27. The method of claim 26 wherein a classfile source is available on a network.

28. The method of claim 26 wherein said communications link is accomplished via carrier wave.

29. The method of claim 26 wherein said at least one classfile comprises a platform independent programming language classfile.

30. The method of claim 29 wherein said platform independent programming language comprises Java programming language.

31. The method of claim 30 wherein said network comprises at least one host computer and said classfile source resides on said host computer.

32. The method of claim 26 wherein said embedded device comprises a personal digital assistant.

33. A method for loading a classfile from a host computer onto an embedded device coupled to said host computer comprising:

identifying a classfile to be loaded from a classfile source in a host computer onto an embedded device, wherein said embedded device operates without a file system;

initiating a conduit on said host computer, said conduit providing a connection between said classfile source and said embedded device such that at least one classfile may be transferred between said classfile source and said embedded device;

registering said conduit with a synching application on said host computer, wherein said synching application provides synchronization of classfiles in said classfile source and said embedded device;

causing a database having said at least one classfile to be opened on said embedded device;

copying said identified classfile from said host computer to said embedded device using said synching application and said conduit;

closing said database in said embedded device after completion of said copying; and

unregistering said conduit with said synching application on said host computer after closing said database.

34. The method of claim 33 wherein said copying said identified classfile to said embedded comprises:

obtaining a directory having said identified classfile;

scanning said directory to determine if said identified classfile has been processed;

obtaining said identified classfile when said identified classfile has not been processed;

copying said identified classfile to said embedded device;

marking said identified classfile as processed in said directory.

35. The method of claim 34 further comprising:

sending a file name of said identified classfile to said embedded device;

sending data of said identified classfile to said embedded device;

writing said file name and said data into said database.

36. The method of claim 33 wherein said embedded device comprises a personal digital assistant (PDA).

37. The method of claim 33 wherein said classfile comprises a bytecode file.

38. The method of claim 37 wherein said bytecode file is a Java™

bytecode file.