Mechanism to load first version classes into a runtime environment running a second version of the class

• US 20060123067A1
• Filed: 01/18/2005
• Published: 06/08/2006
• Est. Priority Date: 12/02/2004
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: BEA Systems Incorporated (Oracle Corporation)
• Inventors: Simpson, Franklin Fulton, Ghattu, Satya Srinivas
• Granted Patent: US 7,543,002 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 9/44552 Conflict resolution, i.e. enabling coexistence of conflicting executables
• CPC Class Codes: G06F 9/45504 Abstract machines for programme code execution, e.g. Java virtual machine [JVM], interpreters, emulators
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99954 Version management

Abstract

In accordance with one embodiment of the present invention, there are provided mechanisms and methods for loading a first version of a class into a second version runtime environment running a second version of the class. The runtime environment may be comprised of a Java Virtual Machine (JVM) in some embodiments. These mechanisms and methods make it possible for applications to retrieve and convert legacy data for use with current versions of the runtime environment. In one embodiment, the conversion of data may be done automatically and/or transparently to a user or calling process.

Claims

1. A method for loading a first version of a class into a second version runtime environment running a second version of the class, the method comprising the computer-implemented steps of:

receiving a first version of a class, the first version of the class being incompatible with a second version class loader of the second version runtime environment;

loading the first version of the class in the second version runtime environment using a first version class loader compatible with the first version of the class; and

automatically converting information according to the first version class into an intermediate storage format for use with the second version runtime environment.

2. The method of claim 1, wherein receiving a first version of a class further comprises:

receiving the first version of the class, the first version of the class being compatible with a first version runtime environment, wherein modification to the first version of the class to yield the second version of the class has rendered the first version class incompatible with the second version class loader of the second version runtime environment.

3. The method of claim 2, wherein a first party controlling the second version of the class is blocked from changing the first version of the class by a second party'"'"'s control over the first version of the class.

4. The method of claim 3, wherein the first party created the second version of the class by modifying the first version of the class prior to relinquishing control over the first version of the class to the second party.

5. The method of claim 3, wherein the second party created the second version of the class by modifying the first version of the class after receiving control over the first version of the class from the first party.

6. The method of claim 2, wherein receiving a first version of a class further comprises:

receiving the first version of the class, wherein the first version of the class is a serializable java class lacking a SerialVersion ID;

thereby causing the first version of the class to be barred from being loaded in the second version runtime environment by the second version class loader.

7. The method of claim 1, wherein loading the first version of the class using a first version class loader further comprises:

defining the first version class loader; and

adding the first version class to a classpath of the first version class loader.

8. The method of claim 1, wherein loading the first version of the class in the second version runtime environment using a first version class loader compatible with the first version of the class, further comprises:

determining a class file name for the class that represents the serialized object;

determining a proper serial version uid; and

determining correct data members to be added to the class.

9. The method of claim 1, wherein converting information according to the first version class into an intermediate storage format further comprises:

converting information according to the first version class into at least one of a string, an XML object, a hashmap and a Java object.

10. The method of claim 1, further comprising:

providing the intermediate storage format data to a process or user requesting loading of the first version of the class.

11. The method of claim 1, further comprising:

loading a second version of the class using a second version class loader, the second version class loader being incompatible with the first version class.

12. The method of claim 1, wherein the second version of the runtime environment comprises a modified version of the first version of the runtime environment.

13. The method of claim 1, wherein automatically converting information according to the first version class into an intermediate storage format for use with the second version runtime environment comprises:

selecting based upon the first version class an appropriate intermediate storage format for the information for use with the second version runtime environment.

14. The method of claim 13, wherein selecting based upon the first version class an appropriate intermediate storage format for the information for use with the second version runtime environment comprises at least one of:

selecting a hashmap as intermediate storage format for the information if the first version class comprises name/value pairings;

selecting an eXtended Markup Language (XML) object as intermediate storage format for the information if the first version class comprises metadata; and

selecting a string object as intermediate storage format for the information if the first version class comprises a long string data.

15. A computer-readable medium carrying one or more sequences of instructions for loading a first version class into a second version runtime environment running a second version of the class, which instructions, when executed by one or more processors, cause the one or more processors to carry out the steps of:

receiving a first version of a class, the first version of the class being incompatible with a second version class loader of a currently instantiated second version runtime environment;

loading the first version of the class in the second version runtime environment using a first version class loader compatible with the first version of the class; and

automatically converting information according to the first version class into an intermediate storage format for use with the second version runtime environment.

16. The computer-readable medium as recited in claim 15, wherein the instructions for carrying out the step of receiving a first version of a class further comprise instructions for carrying out the steps of:

receiving the first version of the class, the first version of the class being compatible with a first version runtime environment, wherein modification to the first version of the class to yield the second version of the class has rendered the first version class incompatible with the second version class loader of the second version runtime environment.

17. The computer-readable medium as recited in claim 16, wherein a first party controlling the second version of the class is blocked from changing the first version of the class by a second party'"'"'s control over the first version of the class.

18. The computer-readable medium as recited in claim 17, wherein the first party created the second version of the class by modifying the first version of the class prior to relinquishing control over the first version of the class to the second party.

19. The computer-readable medium as recited in claim 17, wherein the second party created the second version of the class by modifying the first version of the class after receiving control over the first version of the class from the first party.

20. The computer-readable medium as recited in claim 16, wherein the instructions for carrying out the step of receiving a first version of a class further comprise instructions for carrying out the steps of:

receiving the first version of the class, wherein the first version of the class is a serializable java class lacking a SerialVersion ID;

thereby causing the first version of the class to be barred from being loaded in the second version runtime environment by the second version class loader.

21. The computer-readable medium as recited in claim 15, wherein the instructions for carrying out the step of loading the first version of the class using a first version class loader further comprise instructions for carrying out the steps of:

defining the first version class loader; and

adding the first version class to a classpath of the first version class loader.

22. The computer-readable medium as recited in claim 15, wherein the instructions for carrying out the step of loading the first version of the class using a first version class loader further comprise instructions for carrying out the steps of:

determining a class file name for the class that represents the serialized object;

determining a proper serial version uid; and

determining correct data members to be added to the class.

23. The computer-readable medium as recited in claim 15, wherein the instructions for carrying out the step of converting information according to the first version class into an intermediate storage format further comprise instructions for carrying out the steps of:

converting information according to the first version class into at least one of a string, an XML object, a hashmap and a Java object.

24. The computer-readable medium as recited in claim 15, further comprising instructions which, when executed by the one or more processors, cause the one or more processors to carry out the steps of:

providing the intermediate storage format data to a process or user requesting loading of the first version of the class.

25. The computer-readable medium as recited in claim 15, further comprising instructions which, when executed by the one or more processors, cause the one or more processors to carry out the steps of:

loading a second version of the class using a second version class loader, the second version class loader being incompatible with the first version class.

26. The computer-readable medium as recited in claim 15, wherein the second version of the runtime environment comprises a modified version of the first version of the runtime environment.

27. The computer-readable medium as recited in claim 15, wherein the instructions for automatically converting information according to the first version class into an intermediate storage format for use with the second version runtime environment comprise instructions for carrying out the steps of:

selecting based upon the first version class an appropriate intermediate storage format for the information for use with the second version runtime environment.

28. The computer-readable medium as recited in claim 27, wherein the instructions for selecting based upon the first version class an appropriate intermediate storage format for the information for use with the second version runtime environment comprise instructions for carrying out at least one of the steps of:

selecting a hashmap as intermediate storage format for the information if the first version class comprises name/value pairings;

selecting an eXtended Markup Language (XML) object as intermediate storage format for the information if the first version class comprises metadata; and

selecting a string object as intermediate storage format for the information if the first version class comprises a long string data.

29. An apparatus for loading a first version class into a second version runtime environment running a second version of the class, the apparatus comprising:

a processor; and

one or more stored sequences of instructions which, when executed by the processor, cause the processor to carry out the steps of;

receiving a first version of a class, the first version of the class being incompatible with a second version class loader of a currently instantiated second version runtime environment;

loading the first version of the class in the second version runtime environment using a first version class loader compatible with the first version of the class; and

automatically converting information according to the first version class into an intermediate storage format for use with the second version runtime environment.