Java

Download Object from Google Cloud Storage

See more Google Cloud Storage Examples

Demonstrates how to download an object from Google Cloud Storage to a file. Chilkat2 Java

import com.chilkatsoft.chilkat2.BinData;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Http;
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.

        // This example uses a previously obtained access token having permission for the
        // scope "https://www.googleapis.com/auth/cloud-platform"

        // In this example, Get Google Cloud Storage OAuth2 Access Token,
        // the service account access token was saved to a text file.  This example fetches the access token from the file..
        StringBuilder sbToken = new StringBuilder();
        sbToken.loadFile("qa_data/tokens/googleCloudStorageAccessToken.txt", "utf-8");

        // Send a GET equivalent to this curl command.

        // curl -X GET \
        //     -H "Authorization: Bearer [OAUTH2_TOKEN]" \
        //     -o "[SAVE_TO_LOCATION]" \
        //     "https://www.googleapis.com/storage/v1/b/[BUCKET_NAME]/o/[OBJECT_NAME]?alt=media"

        Http http = new Http();

        http.setAuthToken(sbToken.getAsString());

        // Construct a URL to download an object named "starfish.jpg" from the "chilkat-ocean" bucket.
        http.setUrlVar("bucket_name", "chilkat-ocean");
        http.setUrlVar("object_name", "starfish.jpg");
        String url = "https://www.googleapis.com/storage/v1/b/{$bucket_name}/o/{$object_name}?alt=media";

        // If there is an error response, then we didn't actually download the file data,
        // but instead we downloaded an error response..
        BinData fileData = new BinData();
        try {
            http.downloadBd(url, fileData);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        StringBuilder sbErrorResponse = new StringBuilder();
        int responseCode = http.getLastStatus();
        if (responseCode == 401) {
            System.out.println("If invalid credentials, then it is likely the access token expired.");
            System.out.println("Your app should automatically fetch a new access token and re-try.");
        }

        if (responseCode != 200) {
            // Get the error response
            sbErrorResponse.appendBd(fileData, "utf-8", 0, 0);
            System.out.println("Error response code = " + responseCode);
            System.out.println("Error:");
            System.out.println(sbErrorResponse.getAsString());
            return;
        }

        System.out.println("Success.");

        // Save the downloaded data to a file.
        fileData.writeFile("qa_output/starfish.jpg");
    }
}