Proxy-GoogleCloud

ProxyGoogleCloud.java

HttpTransportFactory hf = new HttpTransportFactory(){
    @Override
    public HttpTransport create() {
        return mHttpTransport;
    }
};            
com.google.auth.oauth2.GoogleCredentials credential = com.google.auth.oauth2.GoogleCredentials.getApplicationDefault(hf);
    if (credential.createScopedRequired())
       credential = credential.createScoped(Arrays.asList("https://www.googleapis.com/auth/devstorage.read_write"));
TransportOptions options = HttpTransportOptions.newBuilder().setHttpTransportFactory(hf).build();            
com.google.cloud.storage.Storage storage = com.google.cloud.storage.StorageOptions.newBuilder()
    .setCredentials(credential)
    .setProjectId("your_project")
    .setTransportOptions(options)
    .build().getService();