While I know there is a community Java based API I have been trying to create a droplet via my own simple app but receive a 400 response code. Please could someone tell me what's wrong with my code.

package code;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;

public class CreateDroplet {

    public static void main(String[] args) {
        String urlString = "https://api.digitalocean.com/v2/droplets";
          String newDroplet = "{'name' : 'ic2gb1'";
          newDroplet += ", 'region' : 'lon1'";
          newDroplet += ", 'size' : '2gb'";
          newDroplet += ", 'image' : 12079764";
          newDroplet += ", 'ssh_keys' : null";
          newDroplet += ", 'backups' : true";
          newDroplet += ", 'ipv6' : false";
          newDroplet += ", 'user_data' : null";
          newDroplet += ", 'private_networking' : false";
                newDroplet += '}';
        URL url;
        try {
            url = new URL(urlString );
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("POST");
            conn.setDoOutput(true);
            conn.setRequestProperty ("Authorization", "Bearer *****************************************************************");
            conn.setRequestProperty("Content-Type", "application/json");
            DataOutputStream writer = new DataOutputStream(conn.getOutputStream());

            writer.writeBytes(newDroplet);
            writer.flush();
            int responseCode = conn.getResponseCode();
            System.out.println("responseCode: + responseCode));
            String line;
            BufferedReader reader = new BufferedReader(new 
                                             InputStreamReader(conn.getInputStream()));
            while ((line = reader.readLine()) != null) {
              System.out.println(line);
            }
            writer.close();
            reader.close();
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

}