将图像上传到Google App Engine上的Blob存储

Question

I am new to app engine and working on uploading an image on blob store. I am uploading image from android application. I have plan to save blob key in an entity, so that I can retrieve it if it matches certain condition.

My problems are :
1. ever since I have implemented "upload handler" blob store is not storing images. Before implementing "Upload handler" it was saving it properly.
2. Another issue is, upload handler is not getting any blob keys.

Please find the code below:

For uploading image following code is used in Android:

public void uploadBlobImage( String path, String link ) {
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost(link);

        try {
            MultipartEntity entity = new MultipartEntity();
            entity.addPart("type", new StringBody("photo"));
            File file = new File( path );
            entity.addPart("data", new FileBody(file, ContentType.create( "image/jpg")/*,"Swapnil.jpg" */));

            httppost.setEntity(entity);
            HttpResponse response = httpclient.execute(httppost);
            Log.d( Utils.AppName, "Image uploaded: "+ response.getStatusLine( ));
        } catch (Exception e) {
            Log.d( Utils.AppName, "Image not uploaded: Exception:"+ e.toString( ));
        }        
    }

Upload link is of the form:

http://<server domain>/_ah/upload/AMmfu6YsZrgX5lDxBjlb5ddPQdGU6kd63WD9nN8FI2rOGpC1VA9qoyYneKYiLvNGNR0Mw-Oi_LyfKzxI9lvL7rjk0CoTuN7O_1rRCmTKLB2c4MOjRWJ8BKuiaquIvcQf-1H47ULHbMoY6w5_lZts8JiG1DDPez8iAQ/ALBNUaYAAAAAUzv_0cB5QIh3hkGn4CokBt0a37zGDAGm/

Upload blob handler code is:

public class UploadBlobHandler extends HttpServlet {

    @Override
    public void doPost(HttpServletRequest req, HttpServletResponse res)
        throws ServletException, IOException {
        BlobstoreService blobstoreService = BlobstoreServiceFactory.getBlobstoreService();

        Map<String, List<BlobKey>> blobs = blobstoreService.getUploads( req );
        Set< String > set = blobs.keySet( );
        Utils.log.log( Level.SEVERE, "UploadBlobHandler.doPost() size::"+set.size( ));
        Iterator< String > iterator = set.iterator( );
        while ( iterator.hasNext( )) {
            Utils.log.log( Level.SEVERE, "UploadBlobHandler.doPost(): Blobstore key: "+iterator.next( ));
        }
        List< BlobKey> list = blobs.get("data");
        for(int i=0;list !=null && i<list.size( );i++){
            BlobKey key = list.get( i );
            Utils.log.log( Level.SEVERE, "UploadBlobHandler.doPost(): Blobstore key: "+key.getKeyString( ));
        }
}

I tried adding and removing following entry in web.xml:

<servlet>
        <servlet-name>UploadBlobHandler</servlet-name>
        <servlet-class>com.swapnilutilities.eRecommendation.servlets.UploadBlobHandler</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>UploadBlobHandler</servlet-name>
        <url-pattern>/upload</url-pattern>
    </servlet-mapping>

On android following log is generated:

Image uploaded: HTTP/1.1 200 OK

On server log was:

0.1.0.30 - - [02/Apr/2014:05:02:02 -0700] "POST /upload HTTP/1.1" 200 53 - "Apache-HttpClient/UNAVAILABLE (java 1.4)" "domain.com" ms=327 cpu_ms=260 cpm_usd=0.000006 app_engine_release=1.9.2 instance=00c61b117cbb73996c2a0799c02bf971906801e2
E 2014-04-02 17:32:02.764
package.UploadBlobHandler doPost: UploadBlobHandler.doPost() size::0
E 2014-04-02 17:32:02.765
package.utils.Utils writeResponse: Swapnil: writeResponse():{"status":0,"ec":0}

Please guide me for this.

Answer 1

Problem got solved. Though I don't understand why did it occur. I changed

new FileBody(file, ContentType.create( "image/jpg")/*,"Swapnil.jpg"*/ )

to

new FileBody(file, ContentType.create( "image/jpg"),"Swapnil.jpg" ).

For some reason it solved the issue.