LinkedIn integration - Establish a requestToken

Question

I'm developing (trying for now) portlet that will be integrated with LinkedIn.

Following the documentation about it: http://developer.linkedin.com/docs/DOC-1008 --> The first step to authorizing a LinkedIn member is requesting a requestToken. This request is done with an HTTP POST. For the requestToken step, the following components should be present in your string to sign:

* HTTP Method (POST)
* Request URI (https://api.linkedin.com/uas/oauth/requestToken)
* oauth_callback
* oauth_consumer_key
* oauth_nonce
* oauth_signature_method
* oauth_timestamp
* oauth_version

I have already API(it's oauth_consumer_key) key and i need to generate specific URL string. Have next java code for this URL and HTTP connection:

private void processAuthentication() {

    Calendar cal = Calendar.getInstance();
    Long ms = cal.getTimeInMillis();
    Long timestamp = ms / 1000;

    Random r = new Random();
    Long nonce = r.nextLong();

    String prefixUrl = "https://api.linkedin.com/uas/oauth/requestToken";
    String oauthCallback = "oauth_callback=http://localhost/";
    String oauthConsumerKey =
            "&oauth_consumer_key=my_consumer_key";
    String oauthNonce = "&oauth_nonce=" + nonce.toString();
    String oauthSignatureMethod = "&oauth_signature_method=HMAC-SHA1";
    String oauthTimestamp = "&oauth_timestamp=" + timestamp.toString();
    String oauthVersion = "&oauth_version=1.0";

    String mainUrl =
            oauthCallback + oauthConsumerKey + oauthNonce + oauthSignatureMethod
                    + oauthTimestamp + oauthVersion;

    try {
        prefixUrl =
                URLEncoder.encode(prefixUrl, "UTF-8") + "&"
                        + URLEncoder.encode(mainUrl, "UTF-8");

        URL url = new URL(prefixUrl);

        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("POST");
        String msg = connection.getResponseMessage();
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

The question is next,for those, who had faced this problem: How should really look URL string for connection and how response is received?

For URL, it's interested the example of URL, you generated. And for response interested, method to get it. As i understand, after HTTP connection been established,that response is:

connection.getResponseMessage();

Answer 1

You might try out the OAuth libraries to handle the connection: http://code.google.com/p/oauth/

Answer 2

@sergionni I found answer to your Question from linkedin-developer

As you know The first step to authorizing a Linked-In member is requesting a requestToken. This request is done with an HTTP POST.

Your base string should end up looking something like this if you're using a callback:

POST&https%3A%2F%2Fapi.linkedin.com%2Fuas%2Foauth%2FrequestToken &oauth_callback%3Dhttp%253A%252F%252Flocalhost%252Foauth_callback%26o auth_consumer_key%3DABCDEFGHIJKLMNOPQRSTUVWXYZ%26 oauth_nonce%3DoqwgSYFUD87MHmJJDv7bQqOF2EPnVus7Wkqj5duNByU%26 oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D1259178158%26 oauth_version%3D1.0

You then sign this base string with your consumer_secret, computing a signature. In this case, if your secret was 1234567890, the signature would be TLQXuUzM7omwDbtXimn6bLDvfF8=.

Now you take the signature you generated, along with oauth_nonce, oauth_callback, oauth_signature_method, oauth_timestamp, oauth_consumer_key, and oauth_version and create an HTTP Authorization header. For this request, that HTTP header would look like:

Authorization: OAuth oauth_nonce="oqwgSYFUD87MHmJJDv7bQqOF2EPnVus7Wkqj5duNByU", oauth_callback="http%3A%2F%2Flocalhost%2Foauth_callback", oauth_signature_method="HMAC-SHA1", oauth_timestamp="1259178158", oauth_consumer_key="ABCDEFGHIJKLMNOPQRSTUVWXYZ", oauth_signature="TLQXuUzM7omwDbtXimn6bLDvfF8=", oauth_version="1.0"

Please note, that the HTTP header is a single header -- not an HTTP header for each component. You can optionally supply a realm="http://api.linkedin.com".

As a response to your request for a requestToken, your requestToken will be in the "oauth_token" response field, a validation that we acknowledged your callback with the "oauth_callback_confirmed" field, an oauth_token_secret, and a oauth_expires_in, and a few other values.

(here us Your answaer) response would look like:

oauth_token=94ab03c4-ae2c-45e4-8732-0e6c4899db63 &oauth_token_secret=be6ccb24-bf0a-4ea8-a4b1-0a70508e452b &oauth_callback_confirmed=true&oauth_expires_in=599

Answer 3

I created a plugin for Play Framework to easily integrated with LinkedIn's OAuth: geeks.aretotally.in/projects/play-framework-linkedin-module. Hopefully it can help. You should def check out Play, very very cool Java framework.

Answer 4

portlet body:

public class LinkedInPortlet extends GenericPortlet {

    public static final String PAGE_PIN = "pin";

    public static final String PAGE_EDIT = "edit";

    public static final String PAGE_PROFILE = "profile";

    public static final String PAGE_CONNECTIONS = "connections";

    public static final String FORM_LINKEDIN_PREFERENCES = "preferencesLinkedInForm";

    public static final String PAGE_VIEW_MY_PROFILE = "/WEB-INF/portlets/linkedin/myProfile.jsp";

    public static final String PAGE_VIEW_MY_CONNECTIONS =
            "/WEB-INF/portlets/linkedin/myConnections.jsp";

    public static final String PAGE_PREFERENCES = "/WEB-INF/portlets/linkedin/edit.jsp";

    public void doView(RenderRequest request, RenderResponse response) throws PortletException,
        IOException {

        String view = PAGE_VIEW_MY_PROFILE;

        String page =
                (String) request.getPortletSession().getAttribute(
                        "page_" + getPortletIdentifier(request), PortletSession.PORTLET_SCOPE);

        String accessTokenToken =
                getStringConfiguration(request, LinkedInPreferencesForm.PARAM_ACCESS_TOKEN_TOKEN);
        String accessTokenSecret =
                getStringConfiguration(request, LinkedInPreferencesForm.PARAM_ACCESS_TOKEN_SECRET);

        LinkedInContact profile = new LinkedInContact();
        List<LinkedInContact> contacts = new ArrayList<LinkedInContact>();

        if (PAGE_PIN.equals(page)) {
            view = PAGE_PREFERENCES;
        } else if (PAGE_EDIT.equals(page)) {
            view = PAGE_PREFERENCES;
        } else if (PAGE_CONNECTIONS.equals(page)) {
            try {
                contacts =
                        ServiceResolver.getResolver().getLinkedInService().getConnections(
                                accessTokenToken, accessTokenSecret);
            } catch (ServiceException se) {
                view = PAGE_PREFERENCES;
                handleException(request, se);
            }
            view = PAGE_VIEW_MY_CONNECTIONS;
        } else {
            try {
                profile =
                        ServiceResolver.getResolver().getLinkedInService().getProfile(
                                accessTokenToken, accessTokenSecret);
            } catch (ServiceException se) {
                view = PAGE_PREFERENCES;
                handleException(request, se);
            }

            view = PAGE_VIEW_MY_PROFILE;
        }

        request.setAttribute("profile", profile);
        request.setAttribute("contacts", contacts);

        response.setContentType(request.getResponseContentType());
        PortletRequestDispatcher rd = getPortletContext().getRequestDispatcher(view);
        rd.include(request, response);

    }

    public void processAction(ActionRequest request, ActionResponse response)
        throws PortletException, IOException {

        String action;

        action = (String) request.getParameter("action");

        String page = request.getParameter("page");

        if (page == null) {
            page = PAGE_PROFILE;
        } else if ("auth".equals(action)) {
            request.getPortletSession().setAttribute(
                    "requestToken_" + getPortletIdentifier(request),
                    ServiceResolver.getResolver().getLinkedInService().getRequestToken(),
                    PortletSession.APPLICATION_SCOPE);
            LinkedInPreferencesForm form = new LinkedInPreferencesForm(request);
            request.getPortletSession().setAttribute(
                    FORM_LINKEDIN_PREFERENCES + getPortletIdentifier(request), form,
                    PortletSession.APPLICATION_SCOPE);
            response.setPortletMode(PortletMode.EDIT);
        } else if ("save".equals(action)) {
            try {
                try {
                    savePreferences(request, response);
                } catch (ServiceException e) {
                    handleException(request, e);
                }
            } catch (PortletModeException e) {
                handleException(request, e);
            }
        } else if ("myProfile".equals(action)) {
            page = PAGE_PROFILE;
        } else if ("myConnections".equals(action)) {
            page = PAGE_CONNECTIONS;
        }

        if (page != null) {
            request.getPortletSession().setAttribute("page_" + getPortletIdentifier(request), page,
                    PortletSession.PORTLET_SCOPE);
        }
    }

    private void savePreferences(ActionRequest request, ActionResponse response)
        throws PortletModeException, ServiceException {

        LinkedInPreferencesForm form = new LinkedInPreferencesForm(request);

        if (validateForm(request, form)) {

            LinkedInRequestToken requestToken =
                    (LinkedInRequestToken) request.getPortletSession().getAttribute(
                            "requestToken_" + getPortletIdentifier(request),
                            PortletSession.APPLICATION_SCOPE);

            String pin = request.getParameter("pinCode");

            LinkedInAccessToken accessToken;

            try {
                accessToken =
                        ServiceResolver.getResolver().getLinkedInService().getAccessToken(
                                requestToken, pin);
            } catch (LinkedInOAuthServiceException ase) {
                response.setPortletMode(PortletMode.EDIT);
                throw new ServiceException("linkedin.authentication.failed");

            }

            String tokenToken = requestToken.getToken();
            String secret = requestToken.getTokenSecret();
            String tokenURL = requestToken.getAuthorizationUrl();

            Properties configuration = new Properties();
            configuration.setProperty(LinkedInPreferencesForm.PARAM_PIN, form.getPin());
            configuration
                    .setProperty(LinkedInPreferencesForm.PARAM_REQUEST_TOKEN_TOKEN, tokenToken);
            configuration.setProperty(LinkedInPreferencesForm.PARAM_REQUEST_TOKEN_SECRET, secret);
            configuration.setProperty(LinkedInPreferencesForm.PARAM_REQUEST_TOKEN_URL, tokenURL);
            configuration.setProperty(LinkedInPreferencesForm.PARAM_ACCESS_TOKEN_TOKEN, accessToken
                    .getToken());

            configuration.setProperty(LinkedInPreferencesForm.PARAM_ACCESS_TOKEN_SECRET,
                    accessToken.getTokenSecret());
            ServiceResolver.getResolver().getPortalService().savePortletConfiguration(request,
                    configuration);

            resetSessionForm(request, FORM_LINKEDIN_PREFERENCES);
            response.setPortletMode(PortletMode.VIEW);

        } else {
            // store in session
            request.getPortletSession().setAttribute(
                    FORM_LINKEDIN_PREFERENCES + getPortletIdentifier(request), form,
                    PortletSession.APPLICATION_SCOPE);
            response.setPortletMode(PortletMode.EDIT);
            logger.debug(FORM_LINKEDIN_PREFERENCES + " is in edit mode");
        }
    }

    @Override
    protected void addConfiguration(MessageSource messageSource, Locale locale,
        Map<String, String> result) {
        result.put(LinkedInPreferencesForm.PARAM_PIN, messageSource.getMessage(
                "linkedIn.preferences.pin", null, locale));
        result.put(LinkedInPreferencesForm.PARAM_REQUEST_TOKEN_TOKEN, messageSource.getMessage(
                "linkedIn.preferences.requestTokenToken", null, locale));
        result.put(LinkedInPreferencesForm.PARAM_REQUEST_TOKEN_SECRET, messageSource.getMessage(
                "linkedIn.preferences.requestTokenSecret", null, locale));
        result.put(LinkedInPreferencesForm.PARAM_REQUEST_TOKEN_URL, messageSource.getMessage(
                "linkedIn.preferences.requestTokenURL", null, locale));
        result.put(LinkedInPreferencesForm.PARAM_ACCESS_TOKEN_TOKEN, messageSource.getMessage(
                "linkedIn.preferences.accessToken", null, locale));
        result.put(LinkedInPreferencesForm.PARAM_ACCESS_TOKEN_SECRET, messageSource.getMessage(
                "linkedIn.preferences.accessTokenSecret", null, locale));
    }

    @Override
    protected void addPreference(MessageSource messageSource, Locale locale,
        Map<String, String> result) {
    }

    @Override
    public String getAsyncTitle(RenderRequest request) {
        return this.getTitle(request);
    }

    protected boolean validateForm(ActionRequest request, LinkedInPreferencesForm form) {
        return form.validate();
    }

    protected String myEdit(RenderRequest request, RenderResponse response)
        throws PortletException, IOException {

        LinkedInPreferencesForm form = new LinkedInPreferencesForm();

        form.setPin(getStringConfiguration(request, LinkedInPreferencesForm.PARAM_PIN));
        form.setRequestTokenToken(getStringConfiguration(request,
                LinkedInPreferencesForm.PARAM_REQUEST_TOKEN_TOKEN));
        form.setRequestTokenSecret(getStringConfiguration(request,
                LinkedInPreferencesForm.PARAM_REQUEST_TOKEN_SECRET));
        form.setRequestTokenURL(getStringConfiguration(request,
                LinkedInPreferencesForm.PARAM_REQUEST_TOKEN_URL));

        registerSessionForm(request, FORM_LINKEDIN_PREFERENCES, form);

        LinkedInRequestToken requestToken;

        requestToken =
                (LinkedInRequestToken) request.getPortletSession().getAttribute(
                        "requestToken_" + getPortletIdentifier(request),
                        PortletSession.APPLICATION_SCOPE);

        if (requestToken == null) {
            requestToken =
                    new LinkedInRequestToken(form.getRequestTokenToken(), form
                            .getRequestTokenSecret());
            requestToken.setAuthorizationUrl(form.getRequestTokenURL());
        }

        request.setAttribute("requestToken", requestToken);

        return PAGE_PREFERENCES;

    }
}