Wednesday, March 9, 2011

Unable to compile JSP on AppEngine

If you are seeing this JSP compile error in eclipse:

An error occurred at line: -1 in the generated java file


The correct answer is to move you AppEngine SDK jar higher in the build path so that the correct JspFactory is found by the class loader. (There is a class by the same name in the GWT jar file.)

Kudos to Mike’s post here, where he gives specific instruction, approximately this:

1) Right click project, select “Properties”
2) Select Java Build Path
3) Select Order and Export
4) Move “App Engine SDK” up so it is above “GWT SDK”