将照片上传到flickr（Java）

Question

I'm a beginner trying to figure out the Flickr API. I'm trying to create a simple app that uploads pics to Flickr.

While trying to send my request to upload a photo I get an "Invalid signature" response.

This is my base string for my signature:

POST&http%3A%2F%2Fapi.flickr.com%2Fservices%2Fupload&oauth_consumer_key%3D3f1e1948c1db9a45ca95febef6f5590e%26oauth_nonce%3D6151b3221a15f56c82ba0df47d57637e%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D1366133923%26oauth_token%3D72157633261587382-7dcbe2359dbcfb06%26oauth_version%3D1.0

I basically did the same thing I did when I requested the user's authentication, but with the access token as an argument.

This is my code for the request:

import java.io.File;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.NoSuchAlgorithmException;
import java.security.SignatureException;

import org.apache.commons.codec.DecoderException;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.DefaultHttpClient;

public class Test {

  /**
   * @param args
 * @throws DecoderException 
 * @throws SignatureException 
 * @throws NoSuchAlgorithmException 
   */
  public static void main(String[] args) throws NoSuchAlgorithmException, SignatureException, DecoderException {
    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost("http://api.flickr.com/services/upload");

    try {
      FileBody bin = new FileBody(new File("/Users/[MYUSERNAME]/Desktop/Untitled-1.png"));

      MultipartEntity reqEntity = new MultipartEntity();
      reqEntity.addPart("photo", bin);

      reqEntity.addPart("api_key", new StringBody(Utils.consumer_key));
      reqEntity.addPart("oauth_token", new StringBody(Utils.oauth_token));
      reqEntity.addPart("api_sig", new StringBody(Request.sig()));
      httppost.setEntity(reqEntity);

      System.out.println("Requesting : " + httppost.getRequestLine());
      ResponseHandler<String> responseHandler = new BasicResponseHandler();
      String responseBody = httpclient.execute(httppost, responseHandler);

      System.out.println("responseBody : " + responseBody);

    } catch (UnsupportedEncodingException e) {
      e.printStackTrace();
    } catch (ClientProtocolException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    } finally {
      httpclient.getConnectionManager().shutdown();
    }
  }

}

Do I have a problem with my understanding of sending a MIME request, or is it just the signature? If so, how should I construct my signature? Thank you.

Answer 1

Basically to do anything with the Flickr api you need some type of authorization "token" - and depending on how you go about authenticating, you may get different authorization tokens. There are 2 types of authorization tokens:

1. oauth token - if you do oauth authentication
2. auth token - if you use the old deprecated authentication method

Flickr's api documentation only shows how to upload using auth token (#2), but it is also possible to upload using Oauth to get an oauth token (just not documented). Your issue seems to be that you are mixing up your ouath token with Flickr's auth token method of uploading.

If you are going to use Oauth authentication you will need to pass Oauth equivalents of the api_key and api_sig , which are oauth_consumer_key and oauth_signature . In addition, a proper Oauth payload should contain oauth_timestamp , oauth_nonce , oauth_signature_method and oauth_version .

One other thing to note: you also need to pass perms=write param in your original Oauth authentication so that a write permission is enabled for your oauth token - otherwise you will lack permissions to upload.

Answer 2

I believe the problem is with the FileBody Constructor

FileBody bin = new FileBody(new File("/Users/[MYUSERNAME]/Desktop/Untitled-1.png"));

If this constructor is used than the result of MultiPart Encoding is

Content-Disposition: form-data; name="photo";

Whereas the expected request should be of the form

Content-Disposition: form-data; name="photo"; filename="Untitled-1.png"

So the correct constructor to be used here is

new FileBody(new File("/Users/[MYUSERNAME]/Desktop/Untitled-1.png"),ContentType.APPLICATION_OCTET_STREAM, "Untitled-1.png")

Although i haven't tried executing your code myself but hopefully this should fix your problem.