User Request 3 (http://myAppServer/MyApp1/firstGrid.jsp)

  1. Dave goes back to welcome.html and clicks a link that points to firstGrid.jsp. An HTTP request for http://myAppServer/MyApp1/firstGrid.jsp is sent.
  2. The application server accesses the cookie and header information to look up the J2EE session ID and verify the security.
  3. The application server first checks to see if this file has been compiled or has changed since it was last compiled.
  4. If compilation is needed, its JSP engine processes and compiles the file into a Java™ class file. The application server checks whether the classes, packages, and tag library descriptor (TLD) files as referenced in the <%@ ...%> directive exist, whether the Java methods and custom tags used are valid, and whether the syntax is correct. The application server then execute through firstGrid.jsp.
  5. It encounters the following scriptlet and processes it. The variable banding gets a value of true or false: 
       <% String banding =
    (Math.random() >= 0.5) ? "true" : "false"; %>
  6. Then it encounters a tag it is unfamiliar with—<blox:grid...>. The prefix blox matches what is specified in the taglib directive <%@ taglib uri="bloxtld" prefix="blox" %>.
  7. The application server goes to the tag library as defined in the taglib directive. Tags are “macros” that are replaced by actual Java code that creates and initializes beans.
  8. Alphablox is now called into duty. Alphablox initializes the bean, user session, application instance, and peers, and sends the results back to the application server. The details on how Blox are processed and served are discussed in the next section, Alphablox program flow.
  9. The application server continues to process the lines in firstGrid.jsp until it reaches the end.
  10. The application server sends the result back to the browser.
Parent topic: Request processing