Java Requires Chilkat v10.1.2+

Dropbox: OAuth2 Authorization to Obtain an Access Token

See more Dropbox Examples

Demonstrates how to get a Dropbox OAuth2 access token from a desktop application or script.

This example runs the OAuth 2.0 authorization flow that lets the user sign in to Dropbox and authorize your app.

Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.JsonObject;
import com.chilkatsoft.chilkat2.OAuth2;

public class ChilkatExample {

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

        OAuth2 oauth2 = new OAuth2();

        // The port should match the Authorized Redirect URL in your Dropbox app,
        // which would look like "http://localhost:3017/"
        oauth2.setListenPort(3017);

        // IMPORTANT: One of the OAuth2 redirect URIs for your Dropbox app must be
        // exactly this string:  http://localhost:3017/

        oauth2.setAuthorizationEndpoint("https://www.dropbox.com/oauth2/authorize");
        oauth2.setTokenEndpoint("https://api.dropboxapi.com/oauth2/token");

        // Replace this with your actual Dropbox App Key
        oauth2.setClientId("DROPBOX_APP_KEY");

        // This is for Require Proof Key for Code Exchange (PKCE)
        // See OAuth2 PKCE Explained
        oauth2.setCodeChallenge(true);
        oauth2.setCodeChallengeMethod("S256");

        // Add token_access_type=offline to also get a refresh token in the response
        oauth2.addAuthQueryParam("token_access_type", "offline");

        // Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
        String url;
        try {
            url = oauth2.startAuth();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            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.
        try {
            oauth2.launchBrowser(url);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Wait for the user to approve or deny authorization in the browser.
        int numMsWaited = 0;
        while ((numMsWaited < 90000) && (oauth2.getAuthFlowState() < 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.getAuthFlowState() < 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.getAuthFlowState() == 5) {
            System.out.println("OAuth2 failed to complete.");
            System.out.println(oauth2.getFailureInfo());
            return;
        }

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

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

        System.out.println("OAuth2 authorization granted!");

        JsonObject json = new JsonObject();
        json.load(oauth2.getAccessTokenResponse());
        json.setEmitCompact(false);

        System.out.println("Access Token Response = " + json.emit());

        // A sample access token response:

        // {
        //   "access_token": "...",
        //   "token_type": "bearer",
        //   "expires_in": 14399,
        //   "refresh_token": "...",
        //   "scope": "account_info.read",
        //   "uid": "562542581",
        //   "account_id": "dbid:AACQhDS0E3_Vb72Ynd0F-GxGWdTI2qcTHzA"
        // }

        System.out.println("Access Token = " + oauth2.getAccessToken());

        // Save the JSON access token response to a file for subsequent use..
        json.writeFile("qa_data/tokens/dropbox.json");
    }
}