Storing and using classes in databases

• US 20060074994A1
• Filed: 09/24/2004
• Published: 04/06/2006
• Est. Priority Date: 09/24/2004
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Smits, Thomas
• Granted Patent: US 7,941,402 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/289 Object oriented databases
• CPC Class Codes: G06F 9/44521 Dynamic linking or loading; Link editing at or after load time, e.g. Java class loading
• CPC Class Codes: G06F 9/44536 Selecting among different versions

Abstract

Methods and apparatus, including computer systems and program products, for storing and using resources, such as classes, in databases. One implementation provides a technique for receiving a specified name, retrieving one or more resources from a database, and for each resource, one or more attributes associated with the resource, wherein each resource comprises executable instruction code, and wherein the attributes include a name that matches the specified name. The technique further provides for selecting one of the retrieved resources based on the attributes associated with each resource, and loading the selected resource into a runtime system. The attributes may include an archive name, an upload time, a package name, a checksum, a development flag, and/or a user name. By utilizing this technique, end-user or development sessions operative on application servers have the capability to use multiple different versions of classes in runtime environments without interfering with other operative sessions.

Claims

1. A computer program product, tangibly embodied in an information carrier, the computer program product comprising instructions operable to cause data processing apparatus to:

receive a specified name;

retrieve one or more resources from a database, and for each resource, one or more attributes associated with the resource, wherein each resource comprises executable instruction code, and wherein the attributes comprise a name that matches the specified name;

select one of the retrieved resources based on the attributes associated with each resource; and

load the selected resource into a runtime system.

2. The computer program product of claim 1, wherein the runtime system is a Java virtual machine or a Common Language Runtime (CLR) virtual machine.

3. The computer program product of claim 1, wherein each resource comprises a class.

4. The computer program product of claim 1, wherein the attributes associated with each resource further comprise one or more of:

an archive name representing a logical archive with which the resource is associated;

an upload time representing the time at which the resource was stored in the database;

a package name representing a package of which the resource is a part;

a checksum computed on the resource;

a development flag representing whether the resource is a development resource; and

a user name representing a developer to whom the resource belongs.

5. The computer program product of claim 4, wherein each resource comprises a class, and wherein the instructions to select one of the retrieved resources comprise instructions to:

receive a specification of a class path; and

identify one of the retrieved resources whose archive name appears first in the class path.

6. The computer program product of claim 4, wherein the instructions to select one of the retrieved resources comprise instructions to:

receive a specification of a start time associated with a user session executing in the runtime system;

sort the retrieved resources by the upload time associated with each of the retrieved resources; and

identify one of the retrieved resources whose upload time is older than and closest to the start time associated with the user session.

7. The computer program product of claim 4, wherein the instructions to select one of the retrieved resources comprise instructions to:

determine if a session executing in the runtime system is associated with a developer; and

if the session is associated with a developer, identify one or more of the retrieved resources whose development flag is set.

8. The computer program product of claim 7, wherein the instructions to select one of the retrieved resources further comprise instructions to:

receive a specification of a name associated with the session; and

if the session is associated with a developer, identify one or more of the retrieved resources whose associated user name matches the name associated with the session.

9. The computer program product of claim 4, wherein the database stores resources in a compressed format, and wherein the instructions are further operable to cause the data processing apparatus to:

decompress the selected resource.

10. The computer program product of claim 4, wherein the instructions are further operable to cause the data processing apparatus to:

use the checksum associated with the selected resource to validate the integrity of the selected resource.

11. A computer-implemented method comprising:

receiving a specified name;

retrieving one or more resources from a database, and for each resource, one or more attributes associated with the resource, wherein each resource comprises executable instruction code, and wherein the attributes comprise a name that matches the specified name;

selecting one of the retrieved resources based on the attributes associated with each resource; and

loading the selected resource into a runtime system.

12. An apparatus comprising:

means for receiving a specified name;

means for retrieving one or more resources from a database, and for each resource, one or more attributes associated with the resource, wherein each resource comprises executable instruction code, and wherein the attributes comprise a name that matches the specified name;

means for selecting one of the retrieved resources based on the attributes associated with each resource; and

means for loading the selected resource into a runtime system.

13. A computer program product, tangibly embodied in an information carrier, the computer program product comprising instructions operable to cause data processing apparatus to:

receive a list identifying one or more resources to be stored in a database, each resource comprising executable instruction code;

read the identified resources; and

for each resource of the identified resources;

compute one or more attributes based on metadata associated with the resource; and

store the resource and its attributes in a separate record in the database.

14. The computer program product of claim 13, wherein the instructions to read the identified resources comprise instructions to:

determine whether any of the identified resources are included in an archive; and

if any of the identified resources are included in an archive, unpack the archive.

15. The computer program product of claim 13, wherein the instructions are further operable to cause the data processing apparatus to:

compress each resource before storing the resource in the database.

16. The computer program product of claim 13, wherein the attributes computed for each resource comprise one or more of:

an archive name representing a logical archive with which the resource is associated;

an upload time representing the time at which the resource is being stored in the database;

a package name representing a package of which the resource is a part;

a checksum computed on the resource;

a development flag representing whether the resource is a development resource; and

a user name representing a developer to whom the resource belongs.

17. The computer program product of claim 16, wherein the instructions are further operable to cause the data processing apparatus to:

identify multiple versions of a resource in the database;

identify an oldest user session that is using the resource;

identify a version of the resource that has been loaded by the oldest user session, the version of the resource being one of the multiple versions of the resource in the database; and

delete all the versions of the resource in the database whose associated upload time is older than the upload time associated with the version of the resource that has been loaded by the oldest user session.

18. The computer program product of claim 13, wherein each resource comprises a class.

19. A computer-implemented method comprising:

receiving a list, the list identifying one or more resources to be stored in a database;

reading the identified resources; and

for each resource of the identified resources;

computing one or more attributes based on metadata associated with the resource; and

storing the resource and its attributes in a separate record in the database.

20. An apparatus comprising:

means for receiving a list, the list identifying one or more resources to be stored in a database;

means for reading the identified resources;

means for computing one or more attributes for each resource of the identified resources based on metadata associated with the resource; and

means for storing each resource of the identified resources and its attributes in a separate record in the database.