(Java) Slack OAuth2

See more OAuth2 Examples

Note: This example requires Chilkat v10.1.2 or greater.

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import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // For more information about the OAuth2, see OAuth 2.0 Authorization Flow

    CkOAuth2 oauth2 = new CkOAuth2();

    // This example is for desktop applicatons (it is not for code that runs on a web server).

    // Your applicaton must use your own public web server as an intermediate
    // to receive and forward the redirect to localhost.
    // See Using Your Web Server as an Intermediary for OAuth2 Redirect to localhost

    // This is the Redirect URL defined for your Slack App in the Slack developer portal, and contains the above PHP.
    oauth2.put_AppCallbackUrl("https://yourwebserver.com/oauth2_redirect");
    oauth2.put_ListenPort(3017);

    oauth2.put_AuthorizationEndpoint("https://slack.com/oauth/authorize");
    oauth2.put_TokenEndpoint("https://slack.com/api/oauth.access");

    // Replace these with actual values.
    oauth2.put_ClientId("CLIENT_ID");
    oauth2.put_ClientSecret("CLIENT_SECRET");

    oauth2.put_Scope("team:read users:read");

    // Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
    String url = oauth2.startAuth();
    if (oauth2.get_LastMethodSuccess() != true) {
        System.out.println(oauth2.lastErrorText());
        return;
        }

    System.out.println("url = " + url);

    // Launch the default browser on the system and navigate to the url.
    // The LaunchBrowser method was added in Chilkat v10.1.2.
    boolean success = oauth2.LaunchBrowser(url);
    if (success == false) {
        System.out.println(oauth2.lastErrorText());
        return;
        }

    // Wait for the user to approve or deny authorization in the browser.
    int numMsWaited = 0;
    while ((numMsWaited < 90000) && (oauth2.get_AuthFlowState() < 3)) {
        oauth2.SleepMs(100);
        numMsWaited = numMsWaited+100;
        }

    // If the browser does not respond within the specified time, AuthFlowState will be:
    // 
    // 1: Waiting for Redirect - The OAuth2 background thread is waiting for the browser's redirect request.
    // 2: Waiting for Final Response - The thread is awaiting the final access token response.
    // In either case, cancel the background task initiated by StartAuth.

    if (oauth2.get_AuthFlowState() < 3) {
        oauth2.Cancel();
        System.out.println("No response from the browser!");
        return;
        }

    // Check AuthFlowState to determine if authorization was granted, denied, or failed:
    // 
    // 3: Success - OAuth2 flow completed, the background thread exited, and the successful response is in AccessTokenResponse.
    // 4: Access Denied - OAuth2 flow completed, the background thread exited, and the error response is in AccessTokenResponse.
    // 5: Failure - OAuth2 flow failed before completion, the background thread exited, and error details are in FailureInfo.

    if (oauth2.get_AuthFlowState() == 5) {
        System.out.println("OAuth2 failed to complete.");
        System.out.println(oauth2.failureInfo());
        return;
        }

    if (oauth2.get_AuthFlowState() == 4) {
        System.out.println("OAuth2 authorization was denied.");
        System.out.println(oauth2.accessTokenResponse());
        return;
        }

    if (oauth2.get_AuthFlowState() != 3) {
        System.out.println("Unexpected AuthFlowState:" + oauth2.get_AuthFlowState());
        return;
        }

    System.out.println("OAuth2 authorization granted!");
    System.out.println("Access Token = " + oauth2.accessToken());

    // Get the full JSON response:
    CkJsonObject json = new CkJsonObject();
    json.Load(oauth2.accessTokenResponse());
    json.put_EmitCompact(false);

    // The JSON response looks like this:

    // {
    //   "ok": true,
    //   "access_token": "xoxp-348475395242-348621810805-4768936228341-9f512b295124e7c9846ce63cb1464c4d",
    //   "scope": "identify,team:read,users:read",
    //   "user_id": "UA8HZRUPP",
    //   "team_id": "TA3DZBN74",
    //   "enterprise_id": null,
    //   "team_name": "Chilkat Testing"
    // }

    System.out.println(json.emit());

    // Save the JSON to a file for future requests.
    CkFileAccess fac = new CkFileAccess();
    fac.WriteEntireTextFile("qa_data/tokens/slack.json",json.emit(),"utf-8",false);
  }
}