Uploading file via form into GAE from Android

问题

I have an app on GAE at: http://1.myawesomecity.appspot.com/

FIXED:

                HttpPost post = new HttpPost("http://1.myawesomecity.appspot.com/");
                http_client.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);
                String result = EntityUtils.toString( http_client.execute(post).getEntity(), "UTF-8");
                String actualURL = result.substring(result.indexOf("http://"), result.indexOf("\" method"));
                Log.w("asdf", "url " + actualURL );


                post = new HttpPost(actualURL);
                http_client.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);                    
                MultipartEntity entity = new MultipartEntity( HttpMultipartMode.BROWSER_COMPATIBLE );
                String mime_type = "image/png";
                File file = new File( filename ); //context.getFilesDir(), 
                entity.addPart( "myFile", new FileBody( file, mime_type));
                post.setEntity( entity );

                String res = EntityUtils.toString( http_client.execute(post).getEntity(), "UTF-8");
                Log.w("asdf", res);

The above grabs the ACTUAL upload URL from the GAE server, and passes in the file as dictated by the CORRECT answer below.

Old Question:

As you can see, if you choose a file and hit submit, it will 404, but the file actually does get stored (as long as it is not too big, < 100kb). Don't type in anything in the first text field.

Now, putting aside how this particular app is barely functional, I'm trying to upload a file from Android onto this server.

The site's upload script uses blobstore, and the file field's name is "myFile".

Now in my Android app, I have:

    HttpClient httpclient = new DefaultHttpClient();

    HttpPost httppost = new HttpPost(<my app's url>);

    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
    nameValuePairs.add(new BasicNameValuePair("myFile", <path to a file selected by user> ) );
    httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

    httpclient.execute(httppost);

This throws an exception.

How is this any different from me going to my site through a browser, choosing a file, and hitting submit? Why does going through a browser actually go through with uploading the file, when the Android code does not?

I know that my filepath is valid. Is there something I'm doing wrong? or is clicking on "submit" from a browser different from executing a httpclient from Android?

回答1:

Uploading file to a blobstore on GAE is a two step process:

first you need to get a proper URL where to POST your data, usually people use something like "/bloburl" handler for that purpose
when you have blob upload URL, you use it in your request.
the file you send does not go as NameValuePair, it's supposed to go as a MultiPartEntity.

here's the code that works (you'll need apache http library for MultiPartEntry support):

DefaultHttpClient http_client = new DefaultHttpClient();
HttpGet http_get = new HttpGet(Config.BASE_URL + "bloburl");
HttpResponse response = http_client.execute(http_get);
BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
String first_line = reader.readLine();
Log.w(TAG, "blob_url: " + first_line);

HttpPost post = new HttpPost(first_line);
http_client.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);
MultipartEntity entity = new MultipartEntity( HttpMultipartMode.BROWSER_COMPATIBLE );

mime_type = "application/zip";
File file = new File( context.getFilesDir(), filename );
entity.addPart( "file", new FileBody( file, mime_type));
post.setEntity( entity );

String result = EntityUtils.toString( http_client.execute(post).getEntity(), "UTF-8");
Log.i(TAG, result);

来源：https://stackoverflow.com/questions/15317270/uploading-file-via-form-into-gae-from-android

标签

android

google-app-engine

blobstore