如何实现MultiPart方法在Android中上传图片

Question

I want to add Image Upload functionality in my app. The thing is that I want to upload a big size image to the server. Thats why I want to use Multipart approach for this scenario. As I am new to this concept I don't know how to implement this. Also I have some specific queries regarding the image upload.

I need to send a POST request to the server in which I have to send JSON data, for example :-

JSONObject jsonObject = new JSONObject();

        jsonObject.put("filename", "menu.jpg");
        jsonObject.put("filetype", "image/jpeg");
        jsonObject.put("user_id", "1");
        jsonObject.put("user_file", "");

Here, the user file is the actual file which I want to upload and the above parameters are the one which I need to send with this Image file to the server and they all are mandatory to upload the file.

Now my question is that how can I send the JSON using MultiPart approach and should I use Volley or AsyncTask to perform the overall steps. Can anyone help me, any help would be appreciable. Thanks

Answer 1

you have to work like this

public void connectForMultipart() throws Exception {
    con = (HttpURLConnection) ( new URL(url)).openConnection();
    con.setRequestMethod("POST");
    con.setDoInput(true);
    con.setDoOutput(true);
    con.setRequestProperty("Connection", "Keep-Alive");
    con.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
    con.connect();
    os = con.getOutputStream();
}

public void addFormPart(String paramName, String value) throws Exception {
    writeParamData(paramName, value);
}

public void addFilePart(String paramName, String fileName, byte[] data) throws Exception {
    os.write( (delimiter + boundary + "\r\n").getBytes());
    os.write( ("Content-Disposition: form-data; name=\"" + paramName +  "\"; filename=\"" + fileName + "\"\r\n"  ).getBytes());
    os.write( ("Content-Type: application/octet-stream\r\n"  ).getBytes());
    os.write( ("Content-Transfer-Encoding: binary\r\n"  ).getBytes());
    os.write("\r\n".getBytes());

    os.write(data);

    os.write("\r\n".getBytes());
}   
public void finishMultipart() throws Exception {
    os.write( (delimiter + boundary + delimiter + "\r\n").getBytes());
}

---

for getting response

httpPost.setEntity(entity);
HttpResponse response = httpClient.execute(httpPost);

BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8"));



String sResponse;
while ((sResponse = reader.readLine()) != null) 
 {
     s = s.append(sResponse);
 }

 if(response.getStatusLine().getStatusCode() == HttpStatus.SC_OK)
 {
     return s.toString();
 }else
 {
     return "{\"status\":\"false\",\"message\":\"Some error occurred\"}";
 }   
} catch (Exception e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

In place of image you can send anything, you would like to... if it creates some heck then you should divide the large file into small parts then try to sending.And Join this small part on the server.

Answer 2

You will no need to add the image in the json object. Please go through this link. I think you will solve your problem. http://www.survivingwithandroid.com/2013/05/android-http-downlod-upload-multipart.html