Http error 500 Problem accessing/index.jsp. Reason: jsp support not configured

I get the openfire source code , compile and run ,everything is well. but cannot open ‘Admin Web Console’ .

the web error code:http error 500 Problem accessing/index.jsp. Reason: jsp support not configured.

the eclipse logcat: 12:02:00,444 INFO /:2052 - No JSP support. Check that JSP jars are in lib/jsp and that the JSP option has been specified to start.jar

what can I do?

Just go to the build folder then execute ant

cd build

ant