I've been following the Google App Engine tutorials, and I'm having a problem with the .jsp file. Here is the code from Google: Using JSPs. I'm using Eclipse to build my project, and for some reason when I add the guestbook.jsp file to the war directory, it instantly gets a red error icon. I can't double click to open guestbook.jsp either. What could be going on here?
3 Suggestions:
Make sure you have this in web.xml:
<welcome-file-list>
<welcome-file>guestbook.jsp</welcome-file>
</welcome-file-list>
Have Project-->Build Automatically enabled, I deployed a Java app on AppEngine long time back and I see a classes folder in the WB-INF folder which has the class of the servlet and the META-INF folder.
In the end I seem to have wasted my bounty as I found the solution (with a little help) myself.
The problem arose because I was unfamiliar with Eclipse. When I found the more verbose error message Your project must be configured to use a JDK in order to use JSPs guestbook.jsp.
It was located in a tab called 'Markers' in pane found at the bottom of the Eclipse window.
It seems that Eclipse wasn't aware that I had installed the JDK.
In Eclipse I went to menu Window->Preferences->Java->Installed JREs . Eclipse had only one entry there named jre6 I clicked the Add... button Chose Standard VM and browsed to the base directory of the jdk (in my case C:\Program Files\Java\jdk1.6.0_20)
I rebuilt my project but the same error was there. I had forgotten to check the box that tells Eclipse to use the jdk instead of the jre.
As soon as I did that Eclipse rebuilt my project and the error was gone.