Hello,
I am going through the Petstore's SignOnFilter class and I am wondering why it has
been named SignOnFilter and not SignInFilter. Isn't the businesss logic of the class
to help the signing in and not the signing on? Am I right or wrong?
Thanks in advance for your replies.
Julien.
Here is the source for the class:
package com.sun.j2ee.blueprints.signon.web;import java.io.PrintWriter;import
java.io.OutputStreamWriter;import java.io.IOException;import java.util.HashMap;import
java.util.Iterator;import java.net.URL;// J2EE importsimport
javax.servlet.ServletException;import javax.servlet.ServletContext;import
javax.servlet.Filter;import javax.servlet.FilterChain;import
javax.servlet.FilterConfig;import javax.servlet.http.HttpSession;import
javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import
javax.servlet.http.HttpServletRequest;import
javax.servlet.http.HttpServletResponse;import javax.servlet.http.Cookie;import
javax.ejb.CreateException;import javax.naming.NamingException;import
javax.naming.InitialContext;// SignOn EJB Importsimport
com.sun.j2ee.blueprints.signon.ejb.SignOnLocalHome;import
com.sun.j2ee.blueprints.signon.ejb.SignOnLocal;public class SignOnFilter implements
Filter { // these static strings define where to put/get things public static
final String FORM_SIGNON_URL = "j_signon_check"; public static final String
FORM_USER_NAME = "j_username"; public static final String FORM_PASSWORD =
"j_password"; public static final String REMEMBER_USERNAME = "j_remember_username";
public static final String USER_NAME = "j_signon_username"; public static final
String SIGNED_ON_USER = "j_signon"; public static final String ORIGINAL_URL =
"j_signon_original_url"; public static final String CREATE_USER_URL =
"j_create_user"; public static final String COOKIE_NAME = "bp_signon"; private
HashMap protectedResources; private FilterConfig config = null; private String
signOnErrorPage = null; private String signOnPage = null; private String
userCreationError = null; public void init(FilterConfig config) throws
ServletException { this.config = config; URL protectedResourcesURL =
null; try { protectedResourcesURL =
config.getServletContext().getResource("/WEB-INF/signon-config.xml");
SignOnDAO dao = new SignOnDAO(protectedResourcesURL); signOnErrorPage =
dao.getSignOnErrorPage(); signOnPage = dao.getSignOnPage();
protectedResources = dao.getProtectedResources(); } catch
(java.net.MalformedURLException ex) { System.err.println("SignonFilter:
malformed URL exception: " + ex); } } public void destroy() {
config = null; } public void doFilter(ServletRequest request, ServletResponse
response, FilterChain chain) throws IOException, ServletException {
HttpServletRequest hreq = (HttpServletRequest)request; String currentURI =
hreq.getRequestURL().toString(); String currentURL = hreq.getRequestURI();
// get everything after the context root int firstSlash =
currentURL.indexOf("/",1); // jump past the starting slash String targetURL =
null; if (firstSlash != -1) targetURL = currentURL.substring(firstSlash + 1,
currentURL.length()); if ((targetURL != null) &&
targetURL.equals(FORM_SIGNON_URL)) { validateSignOn(request, response,
chain); // jump out of this method return; } //
check if the user is signed on boolean signedOn = false; if
(hreq.getSession().getAttribute(SIGNED_ON_USER) != null) { signedOn
=((Boolean)hreq.getSession().getAttribute(SIGNED_ON_USER)).booleanValue(); }
else { hreq.getSession().setAttribute(SIGNED_ON_USER, new Boolean(false));
} // jump to the resource if signed on if (signedOn) {
chain.doFilter(request,response); return; } // find
out if the patterns match the target URL Iterator it =
protectedResources.keySet().iterator(); while (it.hasNext()) {
String protectedName = (String)it.next(); ProtectedResource resource =
(ProtectedResource)protectedResources.get(protectedName); String urlPattern
= resource.getURLPattern(); // now check agains the targetURL if
(urlPattern.equals(targetURL)) { // put the orginal url in the session
so others can access hreq.getSession().setAttribute(ORIGINAL_URL,
targetURL); config.getServletContext().getRequestDispatcher("/" +
signOnPage).forward(request, response); // Jump out of the filter and
go to the next page return; } } // No matches
if we made it to here chain.doFilter(request,response); } public void
validateSignOn(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException { // convert to a http servlet
request for now HttpServletRequest hreq = (HttpServletRequest)request;
HttpServletResponse hres = (HttpServletResponse)response; // get the user name
String userName = hreq.getParameter(FORM_USER_NAME); // get the password
String password = hreq.getParameter(FORM_PASSWORD); // check if the user
wants userName set in cookie String rememberUserName =
hreq.getParameter(REMEMBER_USERNAME); if (rememberUserName != null) {
// set a cookie with the username in it Cookie userNameCookie = new
Cookie(COOKIE_NAME, userName); // set cookie to last for one month
userNameCookie.setMaxAge(2678400); hres.addCookie(userNameCookie); }
else { // see if the cookie exists and remove accordingly
Cookie[] cookies = hreq.getCookies(); if (cookies != null) {
for (int loop=0; loop < cookies.length; loop++) { if
(cookies[loop].getName().equals(COOKIE_NAME)) {
cookies[loop].setMaxAge(0); hres.addCookie(cookies[loop]);
} } } } //validate against the
registered users SignOnLocal signOn = getSignOnEjb(); boolean
authenticated = signOn.authenticate(userName, password); if (authenticated) {
// place a true boolean in the session if
(hreq.getSession().getAttribute(USER_NAME) != null) {
hreq.getSession().removeAttribute(USER_NAME); }
hreq.getSession().setAttribute(USER_NAME, userName); // remove the sign on
user key before putting it back in if
(hreq.getSession().getAttribute(SIGNED_ON_USER) != null) {
hreq.getSession().removeAttribute(SIGNED_ON_USER); }
hreq.getSession().setAttribute(SIGNED_ON_USER, new Boolean(true)); //
redirect to the original destination String targetURL =
(String)hreq.getSession().getAttribute(ORIGINAL_URL);
hres.sendRedirect(targetURL); return; } else {
hres.sendRedirect(signOnErrorPage); return; } } private
SignOnLocal getSignOnEjb() throws ServletException { SignOnLocal signOn =
null; try { InitialContext ic = new InitialContext();
Object o = ic.lookup("java:comp/env/ejb/SignOn"); SignOnLocalHome home
=(SignOnLocalHome)o; signOn = home.create(); } catch
(javax.ejb.CreateException cx) { throw new ServletException("Failed to
Create SignOn EJB: caught " + cx); } catch (javax.naming.NamingException nx) {
throw new ServletException("Failed to Create SignOn EJB: caught " + nx);
} return signOn; }}
