Servlet, GET and POST form problems - forms

Question

I have a problem with only one servlet, all the others (declared in the same way) work nice
Servlet with problem :
package com.myproject.servlets;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
#SuppressWarnings("serial")
public class Connexion extends HttpServlet {
public static final String VUE = "/WEB-INF/connexion.jsp";
public void doGet( HttpServletRequest request, HttpServletResponse response )
throws ServletException, IOException{
this.getServletContext().getRequestDispatcher( VUE ).forward( request, response );
}
public void doPost( HttpServletRequest request, HttpServletResponse response )
throws ServletException, IOException{
}
}
Another Servlet who works :
package com.myproject.servlets;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
#SuppressWarnings("serial")
public class Authentification extends HttpServlet {
public static final String VUE = "/WEB-INF/authentification.jsp";
public void doGet( HttpServletRequest request, HttpServletResponse response )
throws ServletException, IOException{
this.getServletContext().getRequestDispatcher( VUE ).forward( request, response );
}
public void doPost( HttpServletRequest request, HttpServletResponse response )
throws ServletException, IOException{
}
}
The JSP who call the servlet "Connexion" :
<form id="form_authentification" class="formulaire" method="post" action="connexion">
<input type="text" class="input_text" title="<fmt:message key="mail_ou_nom" />" placeholder="<fmt:message key="mail_ou_nom" />" required />
<input type="submit" class="btn" value="<fmt:message key="suivant" /> "/>
And the web.xml :
<!-- Authentification -->
<servlet>
<servlet-name>Authentification</servlet-name>
<servlet-class>com.myproject.servlets.Authentification</servlet-class>
<init-param>
<param-name>auteur</param-name>
<param-value>Atyss</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>Authentification</servlet-name>
<url-pattern>/authentification</url-pattern>
</servlet-mapping>
<!-- Connexion -->
<servlet>
<servlet-name>Connexion</servlet-name>
<servlet-class>com.myproject.servlets.Connexion</servlet-class>
<init-param>
<param-name>auteur</param-name>
<param-value>Atyss</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>Connexion</servlet-name>
<url-pattern>/connexion</url-pattern>
</servlet-mapping>
So If I put the method "get" in the form : "form_authentification" of the JSP authentification.jsp it works but I have in line the browser :
http://localhost:8080/myproject/connexion?
Where from "?" is coming in the line browser?
If I put the method "post" in the form : "form_authentification" of the JSP authentification.jsp I have a white page for connexion.jsp and the browser tag icon of apache server.
Thank you for your answer