System and method for preventing timeout of a client

• US 7,330,894 B2
• Filed: 04/19/2002
• Issued: 02/12/2008
• Est. Priority Date: 04/19/2002
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Vallone, Mark C.
• Primary Examiner(s): Vaughn; William
• Assistant Examiner(s): SERRAO, RANODHI N
• Application Number:
  US10/126,484
• Publication Number:
  US 20030200255A1
• Time in Patent Office: 2,125 Days
• Field of Search: 709/227, 709/203, 719/318
• US Class Current: 709/227
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/142 Managing session states for stateless protocols; Signalling session states; State transitions; Keeping-state mechanisms
• CPC Class Codes: H04L 67/60 Scheduling or organising the servicing of application requests, e.g. requests for application data transmissions using the analysis and optimisation of the required network resources admission control or resource allocation H04L47/70
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

A system for preventing timeout of a client interface accessing a main Java Servlet executing in a first thread which monitors an application executing in a second thread. A task status object is accessed by the application to post its completion state and by the client interface responsive to a state refresh request to post a state refresh response including the completion state to the client. The state refresh response selectively includes a refresh attribute instructing the client to periodically post the state refresh request. Upon the application going to completion or error state, subsequent state refresh responses do not include the refresh attribute.

Claims

1. A method for preventing time out, comprising:

initializing an application for execution in a server for responding to a first request from a client, wherein said client automatically times out if a response to said first request is not received in said client within a pre-determined time-out period;

transmitting a server application state with a refresh attribute from said server to said client, said server application state specifying a state of progress of said application in generating said response to said first request, said refresh attribute specifying a time interval and causing said client to post a state refresh request for refreshing said server application state upon expiration of said time interval, said time interval being less than said pre-determined time-out period;

receiving said state refresh request from said client in said server, said state refresh request being transmitted by said client before expiration of said pre-determined time-out period responsive to said refresh attribute specifying said time interval, wherein posting said state refresh request prevents time-out in said client; and

responsive to said state refresh request from said client, returning to said client a refreshed server application state, said refreshed server application state selectively including said refresh attribute while said application is in the process of generating said response to said first request and not including said refresh attribute upon said application completing generation of said response to said first request or going into an error state.

2. The method of claim 1, further comprising:

executing a client interface class in a first thread;

executing said application in a second thread;

maintaining a task status class accessible by said application for posting said state and by said client interface class for responding to said state refresh requests.

3. The method of claim 2, further comprising:

posting said state to a progress bar task from said task status class;

operating a publish task responsive to said state refresh request to access said progress bar task for said state of completion and derive a hypertext markup language representation of a progress bar for displaying said application state.

4. The method of claim 3, further comprising:

operating said client responsive to said refresh attribute to periodically post said state refresh request to said client interface class.

5. The method of claim 4, further comprising:

operating a browser at said client to display to a user said progress bar.

6. A method of claim 1, wherein said server application state comprises a hypertext markup language (HTML) metatag identifying a state of said application and containing said refresh attribute.

7. The method of claim 6, wherein said HTML metatag specifies a hypertext markup language representation of a progress bar for displaying state of completion of said application.

8. A program storage device readable by a machine, tangibly embodying a program of instructions executable by a machine to perform method steps for preventing time out, comprising:

initializing an application for execution in a server for responding to a first request from a client, wherein said client automatically times out if a response to said first request is not received in said client within a pre-determined time-out period;

transmitting a server application state with a refresh attribute from said server to said client, said server application state specifying a state of progress of said application in generating said response to said first request, said refresh attribute specifying a time interval and causing said client to post a state refresh request for refreshing said server application state upon expiration of said time interval, said time interval being less than said pre-determined time-out period;

receiving said state refresh request from said client in said server, said state refresh request being transmitted by said client before expiration of said pre-determined time-out period responsive to said refresh attribute specifying said time interval, wherein posting said state refresh request prevents time-out in said client; and

responsive to said state refresh request from said client, returning to said client a refreshed server application state, said refreshed server application state selectively including said refresh attribute while said application is in the process of generating said response to said first request and not including said refresh attribute upon said application completing generation of said response to said first request or going into an error state.

9. The program storage device of claim 8, said method further comprising:

executing a client interface class in a first thread;

executing said application in a second thread;

maintaining a task status class accessible said application for posting said state and by said client interface class for responding to said state refresh requests.

10. The program storage device of claim 9, said method further comprising:

posting said state to a progress bar task from said task status class;

operating a publish task responsive to said state refresh request to access said progress bar task for said state of completion and derive a hypertext markup language representation of a progress bar for displaying said application state.

11. The program storage device of claim 10, the method further comprising:

operating said client responsive to said refresh attribute to periodically post said state refresh request to said client interface class.

12. The program storage device of claim 11, said method further comprising:

operating a browser at said client to display to a user said progress bar.

13. A program storage device of claim 8, wherein said server application state comprises a hypertext markup language (HTML) metatag identifying a state of said application and containing said refresh attribute.

14. The program storage device of claim 13, wherein said HTML metatag specifies a hypertext markup language representation of a progress bar for displaying state of completion of said application.

15. A method for operating a web server, comprising the computer-executed steps of:

initializing a web server application for execution in said web server, said web server application for responding to a first request from a client, wherein said client automatically times out if a response to said first request is not received in said client within a pre-determined time-out period;

transmitting a contending instance of a server application state from said web server to said client, said server application state comprising a hypertext markup language (HTML) metatag identifying a state of progress of said web server application in generating said response to said first request and containing a refresh attribute, said refresh attribute specifying a time interval and causing said client to post a state refresh request for refreshing said server application state upon expiration of said time interval, said time interval being less than said pre-determined time-out period;

receiving said state refresh request in said web server, said state refresh request being received from said client responsive to said refresh attribute specifying said time interval, wherein posting said state refresh request prevents time-out in said client;

repeating said transmitting step and said receiving step at least once while said web server application is in the process of generating said response to said first request, each instance of said transmitting step being repeated responsive to receiving a respective state refresh request in said web server from said client responsive to a respective said refresh attribute specifying said time interval, wherein posting each respective state refresh request prevents time-out in said client; and

responsive to receiving an instance of said state refresh request in said web server after said web server application is no longer in the process of generating said response to said first request, transmitting a corresponding instance of said server application state from said web server to said client without said refresh attribute.

16. The method of claim 15, further comprising:

executing a client interface class in a first thread;

executing said web server application in a second thread;

maintaining a task status class accessible by said web server application for posting said server application state and by said client interface class for responding to said state refresh requests.