Question

I was wondering if I can develop a Desktop App for LinkedIn using Java. I know it can be done as a web application easily, but a completely desktop application, is it possible?
I had a look at the linkedin api’s and Java Wrapper for LinkedIn.
The code was explained for a web application. How do I manage that in a java desktop app, specifically the authorization part?
oAuth using Swing?

Please direct me in the right way.

Answer 1

After a very long time of testing with oAuth (with my own wrappers), I settled for Scribe which is a Java Wrapper for almost all oAuth mechanisms. To include Linkedin in a Desktop client, as Adam Trachtenberg (Thank you again) suggested, oob option was used, i.e., after logging in, a code generated by linkedin has to be entered in our Client so that it can be validated against the requested url. Hope this is useful for someone.

public class LinkedInExample
    {
  private static final String PROTECTED_RESOURCE_URL = "http://api.linkedin.com/v1/people/~/connections:(id,last-name)";

  public static void main(String[] args) throws IOException
  {
    OAuthService service = new ServiceBuilder()
                                .provider(LinkedInApi.class)
                                .apiKey("YourApiKey")
                                .apiSecret("YourApiSecret")
                                .build();
    Scanner in = new Scanner(System.in);
    //BareBonesBrowserLaunch.openURL("www.google.com");
    System.out.println("=== LinkedIn's OAuth Workflow ===");
    System.out.println();

    // Obtain the Request Token
    System.out.println("Fetching the Request Token...");
    Token requestToken = service.getRequestToken();
    System.out.println("Got the Request Token!");
    System.out.println();

    System.out.println("Now go and authorize Scribe here:");
    String authURL = service.getAuthorizationUrl(requestToken);
    System.out.println(authURL);
    BareBonesBrowserLaunch.openURL("www.google.com");
    System.out.println("And paste the verifier here");
    System.out.print(">>");
    Verifier verifier = new Verifier(in.nextLine());
    System.out.println();

    // Trade the Request Token and Verfier for the Access Token
    System.out.println("Trading the Request Token for an Access Token...");
    Token accessToken = service.getAccessToken(requestToken, verifier);
    System.out.println("Got the Access Token!");
    System.out.println("(if your curious it looks like this: " + accessToken + " )");
    System.out.println();

    // Now let's go and ask for a protected resource!
    System.out.println("Now we're going to access a protected resource...");
    OAuthRequest request = new OAuthRequest(Verb.GET, PROTECTED_RESOURCE_URL);
    service.signRequest(accessToken, request);
    Response response = request.send();
    System.out.println("Got it! Lets see what we found...");
    System.out.println();
    System.out.println(response.getBody());

    System.out.println();
    System.out.println("Thats it man! Go and build something awesome with Scribe! :)");
  }

}

The BareBonesBrowserLaunch is used to launch the default browser with the Linkedin URL for the token request in most OS’s. Since the Desktop part is not available in Java 1.5, the BareBonesBrowserLaunch solves the problem.

public class BareBonesBrowserLaunch {

   static final String[] browsers = { "google-chrome", "firefox", "opera",
      "epiphany", "konqueror", "conkeror", "midori", "kazehakase", "mozilla" };
   static final String errMsg = "Error attempting to launch web browser";

   public static void openURL(String url) {
      try {  //attempt to use Desktop library from JDK 1.6+
         Class<?> d = Class.forName("java.awt.Desktop");
         d.getDeclaredMethod("browse", new Class[] {java.net.URI.class}).invoke(
            d.getDeclaredMethod("getDesktop").invoke(null),
            new Object[] {java.net.URI.create(url)});
         //above code mimicks:  java.awt.Desktop.getDesktop().browse()
         }
      catch (Exception ignore) {  //library not available or failed
         String osName = System.getProperty("os.name");
         try {
            if (osName.startsWith("Mac OS")) {
               Class.forName("com.apple.eio.FileManager").getDeclaredMethod(
                  "openURL", new Class[] {String.class}).invoke(null,
                  new Object[] {url});
               }
            else if (osName.startsWith("Windows"))
               Runtime.getRuntime().exec(
                  "rundll32 url.dll,FileProtocolHandler " + url);
            else { //assume Unix or Linux
               String browser = null;
               for (String b : browsers)
                  if (browser == null && Runtime.getRuntime().exec(new String[]
                        {"which", b}).getInputStream().read() != -1)
                     Runtime.getRuntime().exec(new String[] {browser = b, url});
               if (browser == null)
                  throw new Exception(Arrays.toString(browsers));
               }
            }
         catch (Exception e) {
            JOptionPane.showMessageDialog(null, errMsg + "\n" + e.toString());
            }
         }
      }

   }

The LinkedInExample is taken mostly from this library – https://github.com/fernandezpablo85/scribe-java/downloads
Don’t forget to include the Scribe jar and apache commons-codec (for Base64)