Save Image in Google Cloud Storage

Question

I'm currently working on a project where we should have the possibility to upload files to the Google Cloud Storage. So we created an Bucket and I added the Maven dependency to my local "normal" application:

<dependencies>
    <dependency>
        <groupId>com.google.appengine.tools</groupId>
        <artifactId>appengine-gcs-client</artifactId>
        <version>RELEASE</version>
    </dependency>
</dependencies>

Then I started to read a local file and tried to push that to the Google Cloud Storage in a simply main:

try {
    final GcsService gcsService = GcsServiceFactory
        .createGcsService();

    File file = new File("/tmp/test.jpg");
    FileInputStream fis = new FileInputStream(file);
    GcsFilename fileName = new GcsFilename("test1213","test.jpg");
    GcsOutputChannel outputChannel;
    outputChannel = gcsService.createOrReplace(fileName, GcsFileOptions.getDefaultInstance());
    copy(fis, Channels.newOutputStream(outputChannel));
} catch (IOException e) {
    e.printStackTrace();
}

My copy method looks like this:

private static final int BUFFER_SIZE = 2 * 1024 * 1024;

private static void copy(InputStream input, OutputStream output)
        throws IOException {
    try {
        byte[] buffer = new byte[BUFFER_SIZE];
        int bytesRead = input.read(buffer);
        while (bytesRead != -1) {
            output.write(buffer, 0, bytesRead);
            bytesRead = input.read(buffer);
        }
    } finally {
        input.close();
        output.close();
    }
}

All I get from that is this:

The API package 'file' or call 'Create()' was not found.

After searching a lot in google, reading documentations even searching in bing i found this entry: The API package 'channel' or call 'CreateChannel()' was not found

It says that there is no way to use the appengine.tools -> gcs-client without such an AppEngine App. But is there an easy way to upload files to the Google Cloud Storage without to be forced on using the AppEngine service?

Answer 1

It sounds like you're not using App Engine. That's completely fine. Google Cloud Storage can work fine with App Engine, but it by no means requires it. The appengine-gcs-client package you're trying to use does require App Engine, though.

Instead, you want google-api-services-storage.

There's an example of using the GCS JSON API with Java and Maven here:

https://cloud.google.com/storage/docs/json_api/v1/json-api-java-samples

Answer 2

Here is the code for my servlet APP Engine which get back data and photo, then store them to datastore and cloud storage. Hope it help you..

@Override
          public void doPost(HttpServletRequest req, HttpServletResponse res)
              throws ServletException, IOException {            

            //Get GCS service
            GcsService gcsService = GcsServiceFactory.createGcsService();

            //Generate string for my photo
            String unique = UUID.randomUUID().toString();     

            //Open GCS File
            GcsFilename filename = new GcsFilename(CONSTANTES.BUCKETNAME, unique+".jpg");               

            //Set Option for that file
            GcsFileOptions options = new GcsFileOptions.Builder()
                    .mimeType("image/jpg")
                    .acl("public-read")
                    .build();


            //Canal to write on it
            GcsOutputChannel writeChannel = gcsService.createOrReplace(filename, options);

            //For multipart support
            ServletFileUpload upload = new ServletFileUpload(); 

            //Trying to create file   
            try {


                FileItemIterator iterator = upload.getItemIterator(req);


                    while (iterator.hasNext()) {
                        FileItemStream item = iterator.next();                      
                        InputStream stream = item.openStream();

                        if (item.isFormField()) {                       

                          String texte_recu_filtre = IOUtils.toString(stream);                       

                          if (item.getFieldName().equals("Type")){
                              Type=Integer.parseInt(texte_recu_filtre);                           
                          }else if (item.getFieldName().equals("DateHeure")){
                              DateHeure=texte_recu_filtre;
                          }else if (item.getFieldName().equals("NumPort")){
                              NumPort=texte_recu_filtre;
                          }else if (item.getFieldName().equals("CodePays")){
                              CodePays=Integer.parseInt(texte_recu_filtre);
                          }

                        } else {                    


                          byte[] bytes = ByteStreams.toByteArray(stream);

                          try {
                                //Write data from photo
                                writeChannel.write(ByteBuffer.wrap(bytes));                             

                          } finally {                             

                                writeChannel.close();
                                stream.close();

                                /
                                res.setStatus(HttpServletResponse.SC_CREATED);

                                res.setContentType("text/plain");
                          }        
                        }        
                  }



                Key<Utilisateur> cleUtilisateur = Key.create(Utilisateur.class, NumPort);               


                Utilisateur posteur = ofy().load().key(cleUtilisateur).now();               

                //Add to datatstore with Objectify
                Campagne photo_uploaded = new Campagne(CONSTANTES.chaineToDelete+unique+".jpg", Type, date_prise_photo, 0, cleUtilisateur, CodePays, posteur.getliste_contact());

                ofy().save().entity(photo_uploaded).now();                          


                } catch (FileUploadException e) {

                    e.printStackTrace();
                }               

         }