Introduction This can have a lot of causes which are broken down in following sections: Put servlet class in a package Set servlet URL in url-pattern @WebServlet works only on Servlet 3.0 or newer javax.servlet.* doesn’t work anymore in Servlet 5.0 or newer Make sure compiled *.class file is present in built WAR Test the … Read more
Introduction To browse and select a file for upload you need a HTML <input type=”file”> field in the form. As stated in the HTML specification you have to use the POST method and the enctype attribute of the form has to be set to “multipart/form-data”. <form action=”upload” method=”post” enctype=”multipart/form-data”> <input type=”text” name=”description” /> <input type=”file” … Read more
Copy pasted your code in my servlet worked fine Check that you overrided doPost method in the servlet Check that you that your post metod work fine and return value, I use “DHC Rest Client” plugin for chrome. It is very cool tool Try to remove httpCon.connect() line. It is not necessary. From oracle docs … Read more
What if you put the check in onfocus instead of onclick? Tabbing to a field technically isn’t a click anyways.
You should always use getParameter, when attribute come from GET or POST method. And use getAttribute when request is forwarded from another servlet/jsp. Such as : ServletA: request.setAttribute(“test”,”value”) request.getRequestDispatcher(“/ServletB”).forward(request, response) ServletB: request.getAttribute(“test”) <– you can get test attribute by using getAttribute