Method and system for on demand java resources

• US 20060112379A1
• Filed: 11/12/2004
• Published: 05/25/2006
• Est. Priority Date: 11/12/2004
• Status: Active Grant

• Current Assignee: Toshiba Global Commerce Solutions Holdings Corporation (Toshiba Corporation)
• Original Assignee: International Business Machines Corporation
• Inventors: Prorock, Thomas Joseph, Chirakansakcharoen, Monsak
• Granted Patent: US 7,444,629 B2
• Time in Patent Office: Days
• US Class Current: 717/166
• CPC Class Codes: G06F 9/445 Program loading or initiating bootstrapping G06F9/4401; security arrangements for program loading or initiating G06F21/57

Abstract

A method and system for using a Java Custom ClassLoader to dynamically build and maintain a list of Java Class Files and resources that are used by applications that run in Point Of Sale (POS) terminals or other POS devices. The Java Class Files and resources are ordinarily obtained from a file server known as a controller. If communication between the POS terminal and the controller is lost, other POS devices dynamically collaborate in a “self healing” process to find and provide the required resources (e.g., Java Class Files) to run the POS terminal in an off-line mode. The present system is thus autonomic, self-learning and self-healing.

Claims

1. A method comprising:

modifying a ClassLoader such that at a runtime of an application running in a first client, the ClassLoader functions as a Class File Listener that monitors all of the Class Files and resources that are actually loaded by the application at runtime;

using the monitored Class Files and resources to dynamically build a list of named resources and associated data that are used by the application;

transmitting a notification message from an offline capable Class Loader in a first client, the notification message stating that the offline capable Class Loader is operational and online with other clients, wherein the notification message includes the dynamically built resource list of named resources and associated data that are used by the application;

listening at the first client for other notification messages from the other clients, wherein a dynamically built resource list is created in the first client of resources and associated data that are stored in the other clients; and

in response to communication between the first client and a primary file server being disrupted, responding, by the first client, to a request for a class file in the application running in the first client by a) sending the requested class file to the application from the first client, or b) if the requested class file is stored in the first client, consulting the resource lists sent from the other clients and, if the requested resource is found, sending the requested class file from another client to the first client, or c) if, after determining that the requested resource is not available from the first client or the other clients, sending a “

resource not found”

message to the application, wherein a collaboration of Class Loaders from the first and other clients supply the requested class files to the first client upon communication between the first client and the primary file server being disrupted.

2. The method of claim 1, wherein the application is a Java application and the Class Loaders are Java Class Loaders.

3. The method of claim 1, wherein the notification messages are sent from the client computer on a pre-defined periodic schedule.

4. The method of claim 1, wherein the client is a Point of Sale (POS) device in a store.

5. The method of claim 4, wherein the POS device is a POS terminal.

6. The method of claim 4, wherein the primary file server is a controller in the store.

7. A method comprising:

creating a Custom Class Loader from a Base Class Loader in a Java environment, wherein the Custom Class Loader is able to load Java class files either using a Java “

import”

mechanism or a Java Class.forName( ) mechanism.

8. The method of claim 7, wherein the Java environment operates within an IBM 4690 Operating System environment.

9. The method of claim 8, wherein the Custom Class Loader operates in a first Point Of Sale (POS) device that is coupled to a controller, the method further comprising:

using the Custom Class Loader to dynamically load Java Classes from the controller to the first POS device, wherein the first POS device requests the Java Classes in response to a request from an application running on the first POS device.

10. The method of claim 9, wherein the first POS device is coupled to other POS devices, the other POS devices including a second POS device and a third POS device, the method further comprising:

upon an interruption in communication between the controller and the first POS device, sending a request from the first POS device to the other POS devices requesting the Java Class.

11. The method of claim 10, further comprising:

storing in the second POS device a record of Java Classes stored in the third POS device;

sending a request for the Java Class from the first POS device to the second POS device, wherein the requested Java Class is not stored in the second POS device, and wherein the requested Java Class is stored in the third POS device; and

in response to the second POS device not having the requested Java Class, sending the first POS device information identifying the third POS device as having the requested Java Class.

12. The method of claim 11, wherein the information includes a TCP/IP address for the third POS device.

13. The method of claim 9, wherein the first POS device is a POS terminal.

14. A computer program product, residing on a computer usable medium, comprising:

program code for creating a Custom Class Loader from a Base Class Loader in a Java environment, wherein the Custom Class Loader is able to load Java class files either using a Java “

import”

mechanism or a Java Class.forName( ) mechanism.

15. The computer program product of claim 14, wherein the Java environment operates within an IBM 4690 Operating System environment.

16. The computer program product of claim 15, wherein the Custom Class Loader operates in a first Point Of Sale (POS) device that is coupled to a controller, the method further comprising:

program code for using the Custom Class Loader to dynamically load Java Classes from the controller to the first POS device, wherein the first POS device requests the Java Classes in response to a request from an application running on the first POS device.

17. The computer program product of claim 16, wherein the first POS device is coupled to other POS devices, the other POS devices including a second POS device and a third POS device, the method further comprising:

upon an interruption in communication between the controller and the first POS device, sending a request from the first POS device to the other POS devices requesting the Java Class.

18. The computer program product of claim 17, further comprising:

program code for storing in the second POS device a record of Java Classes stored in the third POS device;

program code for sending a request for the Java Class from the first POS device to the second POS device, wherein the requested Java Class is not stored in the second POS device, and wherein the requested Java Class is stored in the third POS device; and

program code for, in response to the second POS device not having the requested Java Class, sending the first POS device information identifying the third POS device as having the requested Java Class.

19. The computer program product of claim 18, wherein the information includes a TCP/IP address for the third POS device.

20. The computer program product of claim 16, wherein the first POS device is a POS terminal.