DB2 Everyplace JSP support overview

DB2 Everyplace JSP support consists of two components:

• The mini HTTP Web server
• The JSP processor

The mini HTTP Web server receives requests from a Web browser and sends responses back to the Web browser (using HTTP 1.1 as the protocol for requests and responses). The JSP processor parses a JSP file, generates corresponding Java source code, and compiles the source code. The Java source code may include JavaBeans that generate dynamic content when the JSP page is requested. When a JSP page is requested, the mini HTTP Web server executes the corresponding Java code, and sends the output back to the Web browser as the response to the request.

When you enter a URL such as http://localhost/request.jsp in a Web browser (where request.jsp is the JSP page that you are requesting), the Web browser sends the request to the mini HTTP Web server. The request is forwarded to the JSP processor if one of these conditions is true:

• There is no corresponding .class file for the JSP page (for example, if the JSP page is a newly created page).
• There is a corresponding .class file for the JSP page, but the timestamp on the JSP file is more recent than the timestamp on the .class file (for example, if the JSP page has been modified).

  Note:

  For request.jsp, the corresponding .class file is _request_jsp_.class.

If the request is forwarded to the JSP processor and the JSP file syntax is valid, the mini HTTP Web server sends output to the Web browser indicating that the JSP page is valid. Click the request.jsp link in the output to view the JSP page.

If the request is forwarded to the JSP processor and the JSP file syntax is invalid, the mini HTTP Web server sends diagnostic information to the Web browser.

If the request does not need to be forwarded to the JSP processor, the mini HTTP Web server executes the corresponding .class file for the JSP page and sends the output to the Web browser.

JSP application development should be done on a Windows workstation. It is important to test your JSP pages throughout development. The JSP processor will catch any syntax errors in a JSP page. After the errors are fixed, test the JSP page again by clicking the Refresh button in the Web browser. You may need to delete the files in the Web browser's Temporary Internet Files folder or cache before the changes to the JSP page are reflected. After you complete your application, you can transfer the application to a device and run it on the device.

Note:

The JSP processor runs on the workstation and is not needed on the device.

Related tasks

• Transferring a JSP application to a Windows CE device
• Verifying JSP support on a Windows workstation
• Setting up for JSP development on a Windows CE device

Related concepts

• Developing DB2 Everyplace JSP applications
• The sample JSP applications