Facebook Connect example in JSP (tomcat)

Question

I\'m building a JSP application and I would like to use Facebook Connect as one path for user registration and authentication, but I\'m not finding much information about ho

Answer 1

Haven't used it myself, but there seems to be a (inofficial) Java API on Google Code: http://code.google.com/p/facebook-java-api/

Answer 2

Here is servlet solution I use. With little tweaking you can meke it work in any JSP with simple username-password form. No javascript needed!!! As far as address and phone number go read this: http://developers.facebook.com/blog/post/447

FBAuthServlet

public class FBAuthServlet extends HttpServlet {

private static final Logger log = Logger.getLogger(FBAuthServlet.class);

private static final long serialVersionUID = 1L;

private UserService userService = //here goes your user service implementation

public FBAuthServlet() {
    super();
}

public void destroy() {
    super.destroy(); // Just puts "destroy" string in log
    // Put your code here
}

public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {

    HttpServletRequest req = (HttpServletRequest) request;
    HttpServletResponse res = (HttpServletResponse) response;

    if ("y".equals(request.getParameter("FacebookLogin"))) {
        response.sendRedirect(FaceBookConfig.getLoginRedirectURL());
        return;
    }
    String code = req.getParameter("code");
    if (StringUtil.isNotBlankStr(code)) {
        String authURL = FaceBookConfig.getAuthURL(code);
        URL url = new URL(authURL);
        try {
            String result = readURL(url);
            String accessToken = null;
            Integer expires = null;
            String[] pairs = result.split("&");
            for (String pair : pairs) {
                String[] kv = pair.split("=");
                if (kv.length != 2) {
                    res.sendRedirect(FaceBookConfig.MAINURL);
                } else {
                    if (kv[0].equals("access_token")) {
                        accessToken = kv[1];
                    }
                    if (kv[0].equals("expires")) {
                        expires = Integer.valueOf(kv[1]);
                    }
                }
            }

            if (accessToken != null && expires != null) {

                User user = authFacebookLogin(accessToken, request.getRemoteAddr());
                if (user != null && user.getFacebookId() != null) {
                    //forward to spring security filter chain
                    res.sendRedirect(FaceBookConfig.MAINURL + "/j_spring_security_check?j_username=" + user.getEmail() + "&FaceBookId=" + user.getFacebookId());
                } else if (user != null && StringUtil.isNullOrBlank(user.getFacebookId())) {
                    res.sendRedirect(FaceBookConfig.MAINURL + "/login.html?login_error=You are not Registered By Facebook Connect");

                } else {
                    res.sendRedirect(FaceBookConfig.MAINURL);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
            res.sendRedirect(FaceBookConfig.MAINURL);
        }
    }

}

public void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    doGet(request, response);
}

public void init() throws ServletException {
}

private String readURL(URL url) throws IOException {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    InputStream is = url.openStream();
    int r;
    while ((r = is.read()) != -1) {
        baos.write(r);
    }
    return new String(baos.toByteArray());
}


private User authFacebookLogin(String accessToken, String ip) {
    try {
        String content = IOUtil.urlToString(new URL("https://graph.facebook.com/me?access_token=" + accessToken));

        JSONObject resp = new JSONObject(content);
        String facebookid = resp.getString("id");
        String firstName = resp.getString("first_name");
        String lastName = resp.getString("last_name");
        String email = resp.getString("email");

        log.info("Facebook response: " + content);

        CreateUserRequestCommand comm = new CreateUserRequestCommand();

        comm.setEmail(email);
        comm.setFacebookId(facebookid);
        comm.setFirst(StringAndDateUtils.safeChar(firstName));
        comm.setLast(StringAndDateUtils.safeChar(lastName));
        //if success login
        if (userService.getUserByEmail(email) == null) {
            //if first time login
            User u = userService.createUser(comm, ip);
            return u;
        } else {//if existed
            User existedUser = userService.getUserByEmail(email);
            return existedUser;

        }
    } catch (Throwable ex) {
        ex.printStackTrace();
    }

    return null;
}
}

FBEnableServlet

public class FBEnableServlet extends HttpServlet {

private static final long serialVersionUID = 1L;

private UserService userService = (UserService) ServiceLocator.getContext().getBean("userService");

public FBEnableServlet() {
    super();
}

public void destroy() {
    super.destroy(); // Just puts "destroy" string in log
    // Put your code here
}

public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {

    HttpServletRequest req = (HttpServletRequest) request;
    HttpServletResponse res = (HttpServletResponse) response;

    if ("y".equals(request.getParameter("EnableFacebookConnect"))) {
        response.sendRedirect(FaceBookConfig.getEnableRedirectURL());
        return;
    }
    String code = req.getParameter("code");
    if (StringUtil.isNotBlankStr(code)) {
        String authURL = FaceBookConfig.getEnableAuthURL(code);
        URL url = new URL(authURL);
        try {
            String result = readURL(url);
            String accessToken = null;
            Integer expires = null;
            String[] pairs = result.split("&");
            for (String pair : pairs) {
                String[] kv = pair.split("=");
                if (kv.length != 2) {
                    res.sendRedirect(FaceBookConfig.MAINURL);
                } else {
                    if (kv[0].equals("access_token")) {
                        accessToken = kv[1];
                    }
                    if (kv[0].equals("expires")) {
                        expires = Integer.valueOf(kv[1]);
                    }
                }
            }

            if (accessToken != null && expires != null) {
                User user = authFacebookLogin(accessToken, request.getRemoteAddr());
                String loginedEmail = "";
                try {
                    loginedEmail = SecurityContextHolder.getContext().getAuthentication().getName();
                } catch (Exception ex) {

                }
                System.out.println("Logined email = " + loginedEmail);
                System.out.println("Facebook Login email = " + user.getEmail());
                if (user != null && user.getFacebookId() != null && user.getEmail().equals(loginedEmail)) {
                    userService.setFaceBookid(user.getFacebookId());
                    //forward to spring security filter chain
                    res.sendRedirect(FaceBookConfig.MAINURL + "/j_spring_security_check?j_username=" + user.getEmail() + "&FaceBookId=" + user.getFacebookId());
                } else {
                    res.sendRedirect(FaceBookConfig.MAINURL + "/secure/myAccount.html?message=Please login Facebook with same Email,you Login with " + user.getEmail());
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
            res.sendRedirect(FaceBookConfig.MAINURL);
        }
    }

}

public void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    doGet(request, response);
}

public void init() throws ServletException {
}

private String readURL(URL url) throws IOException {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    InputStream is = url.openStream();
    int r;
    while ((r = is.read()) != -1) {
        baos.write(r);
    }
    return new String(baos.toByteArray());
}


private User authFacebookLogin(String accessToken, String ip) {
    try {
        String content = IOUtil.urlToString(new URL("https://graph.facebook.com/me?access_token=" + accessToken));

        JSONObject resp = new JSONObject(content);
        String facebookid = resp.getString("id");
        String email = resp.getString("email");

        User existedUser = userService.getUserByEmail(email);
        if (existedUser == null) {
            return null;
        } else {
            existedUser.setFacebookId(facebookid);
            return existedUser;
        }


    } catch (Throwable ex) {
        ex.printStackTrace();
    }

    return null;
}
}

Answer 3

It doesn't take long to do the integration yourself, it's just OAuth 2.0 followed by an http request for some user details (json formatted).

We have some code in github (that's quite tied to our social model) that checks the OAuth token and returns the user id (link at bottom of post). You can get the current user's access token from the cookie that the Facebook Connect JavaScript writes (the cookie name begins 'fbs_').

https://github.com/mbst/common-social/blob/master/src/main/java/com/metabroadcast/common/social/auth/facebook/FacebookAccessTokenChecker.java