Display list of files/folders in a Google Cloud Storage(GSC) bucket

ListFilesAndFolderInBucket.java

import com.google.cloud.Page;
import com.google.cloud.storage.Blob;
import com.google.cloud.storage.Storage;
import com.labsite.repository.StorageFactory;

import java.util.Iterator;

/**
 * User: Halil Karakose
 * Date: 31/01/17
 * Time: 21:31
 */
public class ListFilesAndFoldersInBucket {
    private static final String BUCKET_NAME = "ENTER_YOUR_BUCKET_NAME_HERE";
    private static final String SERVICE_ACCOUNT_KEY = "ENTER_YOUR_SERVICE_ACCOUNT_KEY";
    private static final String project_id = "ENTER_YOUR_PROJECT_ID";
    
    public static void main(String[] args) {
        list("");
    }

    public static void list(String directory){
        Storage storage = storageService();
        Page<Blob> blobs = storage.list(BUCKET_NAME, Storage.BlobListOption.currentDirectory(), Storage.BlobListOption.prefix(directory));
        Iterable<Blob> blobIterator = blobs.iterateAll();
        blobIterator.forEach(blob -> {
            if (blob.isDirectory()) {
                list(blob.getName());
            } else {
                System.out.println(blob.getName());
            }
        });
    }

    public static Storage storageService() {
        ServiceAccountCredentials oauth2 = null;
        try {
            oauth2 = ServiceAccountCredentials.fromStream(new StringBufferInputStream(SERVICE_ACCOUNT_KEY));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

        return StorageOptions.newBuilder()
                .setCredentials(oauth2)
                .setProjectId(project_id)
                .build()
                .getService();
    }
}

pom.xml

        <dependency>
            <groupId>com.google.cloud</groupId>
            <artifactId>google-cloud</artifactId>
            <version>0.18.0-alpha</version>
        </dependency>

I updated gist.
You may acquire required dependencies if you use com.google.cloud:google-cloud:0.18.0-alpha