multipart posting for Tumblr on Android.

gistfile1.java

  private static void addValue(String val, String key, OutputStream strm, String boundary) throws UnsupportedEncodingException, IOException {
		strm.write(boundary.getBytes("UTF-8"));
		strm.write("\r\n".getBytes("UTF-8"));
		strm.write("Content-Disposition: form-data; name=\"".getBytes("UTF-8"));
		strm.write(key.getBytes("UTF-8"));
		strm.write("\"\r\n\r\n".getBytes("UTF-8"));
		strm.write(val.getBytes("UTF-8"));
		strm.write("\r\n".getBytes("UTF-8"));
	}
	
	private static void addValue(File val, String key, OutputStream strm, String boundary) throws IOException {
		InputStream is = new FileInputStream(val);
		byte[] indata = new byte[(int)val.length()];
		is.read(indata);
		is.close();

		strm.write(boundary.getBytes("UTF-8"));
		strm.write("\r\n".getBytes("UTF-8"));
		strm.write("Content-Disposition: file; name=\"".getBytes("UTF-8"));
		strm.write(key.getBytes("UTF-8"));
		strm.write("\"; filename=\"file.jpg\"\r\n".getBytes("UTF-8"));
		strm.write("Content-Type: image/jpeg\r\n\r\n".getBytes("UTF-8"));
		strm.write(indata);
		strm.write("\r\n".getBytes("UTF-8"));
	}
	
	public static HttpURLConnection multipartPost(String _url, List<NameValuePair> parameters, List<String> fileKeys, List<File> files, OAuthConsumer consumer) throws UnsupportedEncodingException, IOException, OAuthMessageSignerException, OAuthExpectationFailedException, OAuthCommunicationException {
		final String boundary = "------------0xKhTmLbOuNdArY";
				
		HttpURLConnection con = null;
		con = (HttpURLConnection) new URL(_url).openConnection();
		con.setUseCaches(false);
		con.setDoInput(true);
		con.setDoOutput(true);
		con.setRequestMethod("POST");
		con.setConnectTimeout(60 * 1000);
		
		HttpParameters hp = new HttpParameters();
		Iterator<NameValuePair> pit = parameters.iterator();
		while (pit.hasNext()) {
			NameValuePair pair = (NameValuePair)pit.next();
			String parameterKey = pair.getName();
			String parameterValue = pair.getValue();
			parameterValue = URLEncoder.encode(parameterValue, "UTF-8");
			parameterValue = parameterValue.replace("+", "%20");
			hp.put(parameterKey, parameterValue);
		}
		if (consumer != null) {
			consumer.setAdditionalParameters(hp);
			consumer.sign(con);
		}

		con.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary.substring(2));
		
		OutputStream strm = con.getOutputStream();
		Iterator<String> itr = hp.keySet().iterator();
		while (itr.hasNext()) {
			String parameterKey = itr.next();
			String parameterValue = hp.getFirst(parameterKey, true);
			addValue(parameterValue, parameterKey, strm, boundary);
		}		
		Iterator<String> ki = fileKeys.iterator();
		Iterator<File> fi = files.iterator();
		while (ki.hasNext() && fi.hasNext()) {
			addValue(fi.next(), ki.next(), strm, boundary);
		}
		strm.write(boundary.getBytes("UTF-8"));
		strm.write("--\r\n".getBytes("UTF-8"));
		strm.flush();
		
		con.connect();
		return con;
	}