Java

Get Google Cloud Storage Access Token using Service Account JSON Private Key

See more Google Cloud Storage Examples

Demonstrates how to get a Google Cloud Storage access token using a JSON service account private key. Obtaining an access token for a service account requires no user interaction (it does not require a browser, nor callback URI's, etc.).

When an access token expires, an application can be (and should be) designed to automatically fetch a new access token.

Chilkat2 Java

import com.chilkatsoft.chilkat2.AuthGoogle;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.FileAccess;
import com.chilkatsoft.chilkat2.Socket;
import com.chilkatsoft.chilkat2.StringBuilder;

public class ChilkatExample {

    public static void main(String[] args) {
        // This example requires the Chilkat API to have been previously unlocked.
        // See Global Unlock Sample for sample code.

        // First load the JSON key into a string.
        FileAccess fac = new FileAccess();
        String jsonKey;
        try {
            jsonKey = fac.readEntireTextFile("qa_data/googleApi/ChilkatCloud-13a07a2e8b3f.json", "utf-8");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // A JSON private key should look something like this:

        //     {
        //       "type": "service_account",
        //       "project_id": "chilkattest-1350",
        //       "private_key_id": "fa2e36ee26986eab628b59868af8bec1d1c64c38",
        //       "private_key": "-----BEGIN PRIVATE KEY-----\nMIIEvgIjFa...28N64N2n1E4FYzBZjSdy\n-----END PRIVATE KEY-----\n",
        //       "client_email": "598922945226-00rb0ppfg0sndajo6bhvd4v17jtj2d3a@developer.gserviceaccount.com",
        //       "client_id": "598922945226-00rb0ppfg0snd9jo7bhvd4v17jtj2d3a.apps.googleusercontent.com",
        //       "auth_uri": "https://accounts.google.com/o/oauth2/auth",
        //       "token_uri": "https://accounts.google.com/o/oauth2/token",
        //       "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
        //       "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/598922945226-00rb0ppfg0sndajo6bhvd4v17jtj2d3a%40developer.gserviceaccount.com"
        //     }

        AuthGoogle gAuth = new AuthGoogle();
        gAuth.setJsonKey(jsonKey);

        // Choose a scope.
        gAuth.setScope("https://www.googleapis.com/auth/cloud-platform");

        // Request an access token that is valid for this many seconds.
        gAuth.setExpireNumSeconds(3600);

        // If the application is requesting delegated access:
        // The email address of the user for which the application is requesting delegated access,
        // then set the email address here. (Otherwise leave it empty.)
        gAuth.setSubEmailAddress("");

        // Connect to www.googleapis.com using TLS (TLS 1.2 is the default.)
        // The Chilkat socket object is used so that the connection can be established
        // through proxies or an SSH tunnel if desired.
        Socket tlsSock = new Socket();
        try {
            tlsSock.connect("www.googleapis.com", 443, true, 5000);

            // Send the request to obtain the access token.
            gAuth.obtainAccessToken(tlsSock);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Examine the access token:
        System.out.println("Access Token: " + gAuth.getAccessToken());

        // We're going to save this access token to a file to be used
        // by other examples.
        StringBuilder sbToken = new StringBuilder();
        sbToken.append(gAuth.getAccessToken());
        sbToken.writeFile("qa_data/tokens/googleCloudStorageAccessToken.txt", "utf-8", false);
    }
}