Multipart HTTP Requests Example?

Wrote this snippet to learn more about HTTP Multipart Requests behaviors. Part of an OAUTH client for a REST HTTP service, headaches with Multipart Requests to get the signatures to match before.

public String multipartRequest(String urlTo, String post, String filepath, String filefield) throws ParseException, IOException {
HttpURLConnection connection = null;
DataOutputStream outputStream = null;
InputStream inputStream = null;

String twoHyphens = "--";
String boundary =  "*****"+Long.toString(System.currentTimeMillis())+"*****";
String lineEnd = "\r\n";

String result = "";

int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 1*1024*1024;

String[] q = filepath.split("/");
int idx = q.length - 1;

try {
File file = new File(filepath);
FileInputStream fileInputStream = new FileInputStream(file);

URL url = new URL(urlTo);
connection = (HttpURLConnection) url.openConnection();

connection.setDoInput(true);
connection.setDoOutput(true);
connection.setUseCaches(false);

connection.setRequestMethod("POST");
connection.setRequestProperty("Connection", "Keep-Alive");
connection.setRequestProperty("User-Agent", "Android Multipart HTTP Client 1.0");
connection.setRequestProperty("Content-Type", "multipart/form-data; boundary="+boundary);

outputStream = new DataOutputStream(connection.getOutputStream());
outputStream.writeBytes(twoHyphens + boundary + lineEnd);
outputStream.writeBytes("Content-Disposition: form-data; name=\"" + filefield + "\"; filename=\"" + q[idx] +"\"" + lineEnd);
outputStream.writeBytes("Content-Type: image/jpeg" + lineEnd);
outputStream.writeBytes("Content-Transfer-Encoding: binary" + lineEnd);
outputStream.writeBytes(lineEnd);

bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];

bytesRead = fileInputStream.read(buffer, 0, bufferSize);
while(bytesRead > 0) {
outputStream.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}

outputStream.writeBytes(lineEnd);

// Upload POST Data
String[] posts = post.split("&");
int max = posts.length;
for(int i=0; i<max;i++) {
outputStream.writeBytes(twoHyphens + boundary + lineEnd);
String[] kv = posts[i].split("=");
outputStream.writeBytes("Content-Disposition: form-data; name=\"" + kv[0] + "\"" + lineEnd);
outputStream.writeBytes("Content-Type: text/plain"+lineEnd);
outputStream.writeBytes(lineEnd);
outputStream.writeBytes(kv[1]);
outputStream.writeBytes(lineEnd);
}

outputStream.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);

inputStream = connection.getInputStream();
result = this.convertStreamToString(inputStream);

fileInputStream.close();
inputStream.close();
outputStream.flush();
outputStream.close();

return result;
} catch(Exception e) {
Log.e("MultipartRequest","Multipart Form Upload Error");
e.printStackTrace();
return "error";
}
}


private String convertStreamToString(InputStream is) {
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();


String line = null;
try {
while ((line = reader.readLine()) != null) {
sb.append(line);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}