멀티파트로 파일 올리기(자바, java multipart file upload)

String urlToConnect = "http://example.com/upload";
String paramToSend = "fubar";
File fileToUpload = new File("/path/to/file.txt");
String boundary = Long.toHexString(System.currentTimeMillis()); // Just generate some unique random value.

URLConnection connection = new URL(urlToConnect).openConnection();
connection.setDoOutput(true); // This sets request method to POST.
connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
PrintWriter writer = null;
try {
    writer = new PrintWriter(new OutputStreamWriter(connection.getOutputStream(), "UTF-8"));

    writer.println("--" + boundary);
    writer.println("Content-Disposition: form-data; name=\"paramToSend\"");
    writer.println("Content-Type: text/plain; charset=UTF-8");
    writer.println();
    writer.println(paramToSend);

    writer.println("--" + boundary);
    writer.println("Content-Disposition: form-data; name=\"fileToUpload\"; filename=\"file.txt\"");
    writer.println("Content-Type: text/plain; charset=UTF-8");
    writer.println();
    BufferedReader reader = null;
    try {
        reader = new BufferedReader(new InputStreamReader(new FileInputStream(fileToUpload), "UTF-8"));
        for (String line; (line = reader.readLine()) != null;) {
            writer.println(line);
        }
    } finally {
        if (reader != null) try { reader.close(); } catch (IOException logOrIgnore) {}
    }

    writer.println("--" + boundary + "--");
} finally {
    if (writer != null) writer.close();
}

// Connection is lazily executed whenever you request any status.
int responseCode = ((HttpURLConnection) connection).getResponseCode();
System.out.println(responseCode); // Should be 200



//응답메시지.

BufferedReader in = new BufferedReader( new InputStreamReader ( connection.getInputStream(), "UTF-8")  );

StringBuffer sb = new StringBuffer();

String output = "";

while( ( output = in.readLine() ) != null )

{

if( !output.equals( "") )

{

sb.append( output.trim() );

}

}



in.close();



System.out.println( sb.toString() );