Exception handler works for doGet(), but not for doPost() - servlets

Question

I have a servlet api where I used to throw my own exceptions from servlets level
When I throw exception from doGet method everything works fine and exception handler catches and processed my exception. the problem ocures when I throw exception from doPost method. in this case unfortunatelly I never see error page
web.xml
<error-page>
<exception-type>java.lang.Throwable</exception-type >
<location>/ErrorHandler</location>
</error-page>
exception handler
#WebServlet("/ErrorHandler")
public class ErrorHandler extends HttpServlet {
private final Logger logger;
public ErrorHandler() {
logger = Logger.getLogger(ErrorHandler.class);
}
#Override
public void doGet(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws IOException, ServletException {
Throwable throwable = (Throwable) httpServletRequest.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
logger.error("occurred exception: ", throwable);
httpServletRequest.getRequestDispatcher("/error.jsp").forward(httpServletRequest, httpServletResponse);
}
}
Servlet
#Override
public void doPost(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws IOException {
throw new UserException("error message");
}

Answer 1

Add to your ErrorHandler
#Override
public void doPost(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws IOException, ServletException {
Throwable throwable = (Throwable) httpServletRequest.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
logger.error("occurred exception: ", throwable);
httpServletRequest.getRequestDispatcher("/error.jsp").forward(httpServletRequest, httpServletResponse);
}
To avoid code duplication consider creating third method
private void processError(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
Throwable throwable = (Throwable) httpServletRequest.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
logger.error("occurred exception: ", throwable);
httpServletRequest.getRequestDispatcher("/error.jsp").forward(httpServletRequest, httpServletResponse);
}
and invoke it from both doGet() and doPost()
#Override
public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
processError(req, resp);
}
#Override
public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
processError(req, resp);
}