Issue
If I have action to a servlet, we should use mapping in XML which is recommended. So it would look like this:
HTML index:
<!DOCTYPE html>
</head><body>
<form action="go" method="POST">
Enter name: <input type="text" name="name">
<button>Submit form :)</button>
</form>
</body></html>
XML mapping:
<web-app..........
<servlet>
<servlet-name>servlet</servlet-name>
<servlet-class>ServletOne</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>servlet</servlet-name>
<url-pattern>/go</url-pattern>
</servlet-mapping>
</web-app>
Servlet class
public class ServletOne extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
String s = req.getParameter("name");
PrintWriter pw = resp.getWriter();
pw.println("Welcome " + s);
}
}
And it works fine. But my question is what if I don't want to make a mapping - I want to call Servlet class directly. I removed my XML file and I did all of these lines:
<form action="ServletOne" method="POST">
<form action="ServletOne.class" method="POST">
<form action="ServletOne.java" method="POST">
And.. none of them work. Can I actually call Servlet directly without mapping at all? If yes, how? Sometimes for testing purposes, I don't need to waste time on mapping every servlet.
Solution
You can use annotation e.g.
@WebServlet("/go")
public class ServletOne extends HttpServlet {
//...
}
In fact, Servlet 3.0 onwards, most of the developers prefer this to XML configuration.
Note that the Servlet Specification requires the mapping to start with a /. Check this to learn more about it.
Answered By - Arvind Kumar Avinash
Answer Checked By - David Goodson (JavaFixing Volunteer)
