如何从另一个Sevlet设置JSP属性？

Question

I have a login and a register form in the same JSP, but I'd like to them to call two different servlet. The main functions are works, so you can log in or register, but if something happened, I'd like to change a ${message} attribute on the main page both from the Login and the Register servlet. How can I do it?

Login JSP page (login.jsp)

<form action="register" method="POST">
    INPUTS...
</form>
<form action="login" method="POST">
    INPUTS...
</form>

Login Servlet (LoginSV.java)

protected void doPost(HttpServletRequest request, HttpServletResponse response) {
    //Happens when e-mail or password incorrect
    request.setAttribute("message", "Incorrect email/password.");
    request.getRequestDispatcher("/login.jsp").forward(request, response);
    return;
}

Register Servlet (RegisterSV.java)

protected void doPost(HttpServletRequest request, HttpServletResponse response) {       
    //Happens if user leaves a field empty
    request.setAttribute("message", "One or more field is epty.");
    request.getRequestDispatcher("/login.jsp").forward(request, response);
    return;
}

web.xml

<servlet>
    <servlet-name>LoginSV</servlet-name>
    <servlet-class>servlet.LoginSV</servlet-class>
</servlet>
<servlet>
    <servlet-name>RegisterSV</servlet-name>
    <servlet-class>servlet.RegisterSV</servlet-class>
</servlet> 

<servlet-mapping>
    <servlet-name>LoginSV</servlet-name>
    <url-pattern>/login</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>RegisterSV</servlet-name>
    <url-pattern>/register</url-pattern>
</servlet-mapping>

I have the forms in the login.jsp file, so the Login Servlet can change the attribute (so it works fine in case the login form calls it), but the Register can't, the ${message} variable isn't there in any form.

Answer 1

The problem solved. There were a redirect script in the login.jsp what screwed the things up. Thanks everyone.