Issue
I have simple servlet that prints something to response
@WebServlet(name = "helloServlet", value = "/hello-servlet" , s )
public class HelloServlet extends HttpServlet {
private String message;
public void init() {
message = "Hello World!";
}
public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
response.setContentType("text/html");
// Hello
PrintWriter out = response.getWriter();
out.println("<html><body>");
out.println("<h1>" + message + "</h1>");
out.println("</body></html>");
}
public void destroy() {
}
}
that what web.xml looks like:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<welcome-file-list>
<welcome-file>hello-servlet</welcome-file>
</welcome-file-list>
</web-app>
and the problem is that url isn`t changed when it redirect to servlet in welcome-file list
my url : http://localhost:8080/testsss_war_exploded/
but should be : http://localhost:8080/testsss_war_exploded/hello-servlet
Solution
That is the way welcome resources are supposed to work:
The container may send the request to the welcome resource with a forward, a redirect, or a container specific mechanism that is indistinguishable from a direct request.
Tomcat redirects the request internally. If you want to send a HTTP redirect, you need to do it yourself. You can check the original URI to see if the request was forwarded by the welcome files mechanism:
@WebServlet(name = "helloServlet", urlPatterns = {"/hello-servlet"})
public class HelloServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
if (req.getRequestURI().endsWith("/")) {
resp.sendRedirect("hello-servlet");
return;
}
}
Another solution would be to renounce the the welcome files mechanism and explicitly bind your servlet to the applications root:
@WebServlet(name = "helloServlet", urlPatterns = {"", "/hello-servlet"})
public class HelloServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
if (req.getServletPath().isEmpty()) {
resp.sendRedirect("hello-servlet");
return;
}
}
Answered By - Piotr P. Karwasz
Answer Checked By - Pedro (JavaFixing Volunteer)
