Can not load resenly created HTML or PDF file

I had done a vaadin application to generate report. (here., when I click a button to create a .html or .pdf in the tomcat server (ie., tomcat/webapps/vaadinproject/report/file.html)). the file is created when the button was pressed. but the link show 404 error the file not available. but I restart tomcat and refresh the link shows the report. give me a solution to show html file with out restart tomcat.