ROOT does not mean what you think it means.
ROOT is the "default" web application. The one that is accessed if the url doesn't match any existing contexts.
Your WEB-INF directory must always be in the top level of your web application to have any effect.
Because you have yours in webapps/ROOT/test_jsp/WEB-INF, it doesn't recognise it as valid. As a result it doesn't recognise the classes directory, and can't find your java class.
Move your test_jsp folder up a level from ROOT to webapps. ie: webapps/test_jsp
Restart your server.
Things should start working as you expect at that point.