How can I use an Async Task to upload a file to the server?

Question

Below is my code for uploading a file to the server. But I\'m getting network exceptions even after several tries and even after adding strict mode.

I\'m new to Andr

Answer 1

/**
 * *******Async Task for Use this UTILITY CLASS *
 * pass the file which need to upload *
 * Progress dialog commente/ Uncomment according requirment*******/

private class ImageUploaderTask extends AsyncTask<String, Integer, Void> {
    @Override
    protected void onPreExecute(){
        //  simpleWaitDialog = ProgressDialog.show(BlogPostExamplesActivity.this, "Wait", "Uploading Image");
    }
    @Override
    protected Void doInBackground(String... params) {
        new ImageUploadUtility().uploadSingleImage(params[0]);
        return null;
    }
    @Override
    protected void onPostExecute(Void result){
        //  simpleWaitDialog.dismiss();
    }

    /**
     * Method uploads the image using http multipart form data.
     * We are not using the default httpclient coming with android we are using the new from apache
     * they are placed in libs folder of the application
     *
     * @param imageData
     * @param filename
     * @return
     * @throws Exception
     */
    static boolean doUploadinBackground(final byte[] imageData, String filename) throws Exception{
        String responseString = null;
        PostMethod method;
        method = new PostMethod("your url to upload");
        org.apache.commons.httpclient.HttpClient client = new org.apache.commons.httpclient.HttpClient();
        client.getHttpConnectionManager().getParams().setConnectionTimeout(
                                                                           100000);
        FilePart photo = new FilePart("userfile", new ByteArrayPartSource(
                                                                          filename, imageData));
        photo.setContentType("image/jpeg");
        photo.setCharSet(null);
        String s  =  new String(imageData);
        Part[] parts = {
            new StringPart("latitude", "123456"),
            new StringPart("longitude","12.123567"),
            new StringPart("imei","1234567899"),
            new StringPart("to_email","some email"),
            photo
        };
        method.setRequestEntity(new MultipartRequestEntity(parts, method
                                                           .getParams()));
        client.executeMethod(method);
        responseString = method.getResponseBodyAsString();
        method.releaseConnection();
        Log.e("httpPost", "Response status: " + responseString);
        if (responseString.equals("SUCCESS")) {
            return true;
        } else {
            return false;
        }
    }
    /**
     * Simple Reads the image file and converts them to Bytes
     *
     * @param file name of the file
     * @return byte array which is converted from the image
     * @throws IOException
     */
    public static byte[] getBytesFromFile(File file) throws IOException {
        InputStream is = new FileInputStream(file);
        // Get the size of the file
        long length = file.length();
        // You cannot create an array using a long type.
        // It needs to be an int type.
        // Before converting to an int type, check
        // to ensure that file is not larger than Integer.MAX_VALUE.
        if (length > Integer.MAX_VALUE) {
            // File is too large
        }
        // Create the byte array to hold the data
        byte[] bytes = new byte[(int)length];
        // Read in the bytes
        int offset = 0;
        int numRead = 0;
        while (offset < bytes.length
               && (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) {
            offset += numRead;
        }
        // Ensure all the bytes have been read in
        if (offset < bytes.length) {
            throw new IOException("Could not completely read file "+file.getName());
        }
        // Close the input stream and return bytes
        is.close();
        return bytes;
    }
}

Answer 2

mButton.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {

new UploadImageTask().execute(); // initialize asynchronous task

}});

//Now implement Asynchronous Task


public class Get_User_Data extends AsyncTask<Void, Void, Void> {

            private final ProgressDialog dialog = new ProgressDialog(
            MyActivity.this);

    protected void onPreExecute() {
        this.dialog.setMessage("Loading...");
        this.dialog.setCancelable(false);
        this.dialog.show();
    }
        @Override
        protected Void doInBackground(Void... params) {

                    uploadImage(); // inside the method paste your file uploading code
            return null;
        }

        protected void onPostExecute(Void result) {

            // Here if you wish to do future process for ex. move to another activity do here

            if (dialog.isShowing()) {
                dialog.dismiss();
            }

        }
    }

For more information refer this link http://vikaskanani.wordpress.com/2011/01/29/android-image-upload-activity/