My project works fine locally, but when trying to deploy it to the GAE servers, I get the following error message:
Unable to update app: Failed to compile the generated JSP java files.
This happened mainly when I switched from Java 7 to Java 6, since apparently GAE doesn’t support that yet. I am using GAE 1.7.4, is this a known problem? What is wrong with the project? Is it syntax within the JSPs? They used to compile before I starting using GAE 1.7.4, but I don’t know the exact cause of when this started.
I have been having the same problem and was convinced that there was a GAE problem. However, now I realize that I had changed the name of a .java file referenced by a couple of my .jsp files and the file name had not gotten changed in the .jsp. After I fixed the file name in the .jsp deployment worked normally again. Arrgh.
I think before GAE started compiling the JSP files, JSP files with errors would deploy successfully. Also, when running locally, the JSP are apparently not compiled until they are accessed, so unless all the JSP files are tested locally, you may not know of the error. But if you try to deploy, the JSP compilation fails and the deploy is aborted. Unfortunately, there is no sensible error message to suggest where the problem was found.