| Methods Summary |
|---|
| public void | destroy()Resets the instance variable.
config = null;
|
| public void | doFilter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain chain)Looks for the authentication token in the session and forwards
to the login page if not found.
HttpServletRequest httpReq = (HttpServletRequest) request;
HttpServletResponse httpResp = (HttpServletResponse) response;
if (!isAuthenticated(httpReq)) {
String forwardURI = getForwardURI(httpReq);
// Forward to the login page and stop further processing
ServletContext context = config.getServletContext();
RequestDispatcher rd = context.getRequestDispatcher(forwardURI);
if (rd == null) {
httpResp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
"Login page doesn't exist");
}
rd.forward(request, response);
return;
}
/*
* Process the rest of the filter chain, if any, and ultimately
* the requested servlet or JSP page.
*/
chain.doFilter(request, response);
|
| private java.lang.String | getContextRelativeURI(javax.servlet.http.HttpServletRequest request)Returns a context-relative path for the request, including
the query string, if any.
int ctxPathLength = request.getContextPath().length();
String requestURI = request.getRequestURI();
StringBuffer uri =
new StringBuffer(requestURI.substring(ctxPathLength));
String query = request.getQueryString();
if (query != null) {
uri.append("?").append(query);
}
return uri.toString();
|
| private java.lang.String | getForwardURI(javax.servlet.http.HttpServletRequest request)Returns the context-relative path to the login page, with the
parameters used by the login page.
StringBuffer uri = new StringBuffer(loginPage);
uri.append("?errorMsg=Please+log+in+first&origURL=").
append(URLEncoder.encode(getContextRelativeURI(request)));
return uri.toString();
|
| public void | init(javax.servlet.FilterConfig config)Reads the "loginPage" filter init parameter and saves the
value in an instance variable.
this.config = config;
loginPage = config.getInitParameter("loginPage");
if (loginPage == null) {
throw new ServletException("loginPage init parameter missing");
}
|
| private boolean | isAuthenticated(javax.servlet.http.HttpServletRequest request)Returns true if the session contains the authentication token.
boolean isAuthenticated = false;
HttpSession session = request.getSession();
if (session.getAttribute("validUser") != null) {
isAuthenticated = true;
}
return isAuthenticated;
|
