Before calling the Engine Bean, you must make sure that:
<install_root>\lib\JREngine.jar;<install_root>\lib\log4j-1.2.8.jar.
<install_root>\bin and then check whether it is valid by setting a runtime key in the bean. If you then open report.ini, you will find that the configuration information, including the temporary path, template path and the help path. JReport Engine Bean uses the temporary path to export temporary files. You should therefore make sure that the temporary folder specified in report.ini exists.