System for integrating java servlets with asynchronous messages

• US 7,003,570 B2
• Filed: 10/03/2002
• Issued: 02/21/2006
• Est. Priority Date: 10/05/2001
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: BEA Systems Incorporated (Oracle Corporation)
• Inventors: Messinger, Adam, Pullara, Sam, Brown, Dave
• Primary Examiner(s): Vaughn, Jr., William C.
• Application Number:
  US10/264,973
• Publication Number:
  US 20030084097A1
• Time in Patent Office: 1,237 Days
• Field of Search: 709203-207, 709/226, 719315-319, 707/104.1
• US Class Current: 709/226
• CPC Class Codes: G06F 9/546 Message passing systems or structures, e.g. queues
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 69/12 Protocol engines
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

In a traditional application server that uses servlets, when a request is dispatched to a thread the service( ) method of the appropriate servlet is called. When the service( ) method returns the response is sent. This is sub-optimal in the case that an asynchronous event must occur before the response can be sent, because the thread running the servlet must block until the event occurs. The invention provides for asynchronous processing of such requests. In one embodiment, the invention provides an extension to the Servlet API which allows the service( ) method to return (and thus the thread to be freed) before the response is ready to be sent. Then when the asynchronous event later occurs the response may be completed and sent.

Claims

1. A system for asynchronous messaging between Java servlets and an HTTP client, comprising:

a server including a servlet container, a servlet and a servlet response handler;

an HTTP interface at the servlet container that receives requests from, and sends responses to an HTTP client, wherein a request from the HTTP client is transmitted by the servlet container to the servlet; and

wherein the servlet assumes responsibility for processing the requests, including

receiving a request from the servlet container and immediately returning a partial response data via the servlet response handler to release the servlet response handler from waiting for a complete response,

setting a response code to be used with subsequent responses,

releasing the response handler to interleave the processing of subsequent requests from the HTTP client or from other HTTP clients, and

subsequently processing the original request by locating the required information, resetting the response code, and sending the information to the HTTP client via the servlet response handler.

2. The system of claim 1 wherein the servlet subsequent response is triggered by a response command to send additional response data.

3. The system of claim 2 wherein the response command is a JMS message.

4. The system of claim 1 wherein the functioning of the servlet and servlet response handler is exposed to the user via a JSP tag library.

5. The system of claim 4 wherein the JSP tag library is used to indicate which HTTP response data should be returned immediately and which response data should be returned later.

6. The system of claim 4 further comprising support for JSP execution contexts.

7. The system of claim 1 wherein the system includes an extension to the http interface that allows a service( ) method to return, and allows the thread handling that service( ) method to be freed-up before the response is ready to be sent.

8. The system of claim 1 further including a Java Messaging Service, wherein when a servlet is executed, it builds a portion of a response, queues a JMS message requesting the data, and creates a response object as the response code, which is later retrieved when another JMS message containing the requested data arrives.

9. The system of claim 1 wherein the system sets a period of time t for which to send subsequent responses, after which period of time t the servlet sends a send signal to the response handler, which then sends a send-response signal to the servlet container to send the response to the client.

10. The system of claim 1 wherein the system is used to provide information within a search function to a user of a web page, and wherein the system provides partial items of information to the user'"'"'s screen, while other items of information are returned successively to the user'"'"'s screen as the servlet finds the appropriate data and returns it.

11. A method for asynchronous messaging between Java servlets and an HTTP client, comprising the steps of:

receiving a request from an HTTP client to access a servlet contained in a servlet container; and

responding to said requests asynchronously, including the steps of

receiving a request at the servlet from the servlet container and immediately returning a partial response data via a servlet response handler to release the servlet response handler from waiting for a complete response,

setting a response code to be used with subsequent responses,

releasing the response handler to interleave the processing of subsequent requests from the HTTP client or from other HTTP clients, and

subsequently processing the original request by locating the required information, resetting the response code, and sending the information to the HTTP client via the servlet response handler.

12. The method of claim 11 wherein the servlet subsequent response is triggered by a response command to send additional response data.

13. The method of claim 12 wherein the response command is a JMS message.

14. The method of claim 11 wherein the functioning of the servlet and servlet response handler is exposed to the user via a JSP tag library.

15. The method of claim 14 wherein the JSP tag library is used to indicate which HTTP response data should be returned immediately and which response data should be returned later.

16. The system of claim 14 further comprising support for JSP execution contexts.

17. The method of claim 11 further comprising providing an extension to the http interface that allows a service( ) method to return, and allows the thread handling that service( ) method to be freed-up before the response is ready to be sent.

18. The method of claim 11 further comprising using a Java Messaging Service, including wherein when a servlet is executed, building a portion of a response, queuing a JMS message requesting the data, and creating a response object as the response code, which is later retrieved when another JMS message containing the requested data arrives.

19. The method of claim 11 further comprising setting a period of time t for which to send subsequent responses, after which period of time t sending by the servlet a send signal to the response handler, which then sends a send-response signal to the servlet container to send the response to the client.

20. The method of claim 11 wherein the method is used to provide information within a search function to a user of a web page, and wherein the method provides partial items of information to the user'"'"'s screen, while other items of information are returned successively to the user'"'"'s screen as the servlet finds the appropriate data and returns it.