Invoke curl to do HTTP POST in JAVA

doPostWithCurl.java

	/*
   * Sends a POST request to target URL by forking curl.
	 * Returns the response content on success; Otherwise returns null.
	 * 
   */
	private static String sendPostWithCurl (String url) {
		
		String [] cmdOptions = new String[] {"/usr/bin/curl", "-k", "-H \"Content-Length: 0\"", "-X", "POST", url};
		StringBuilder builder = new StringBuilder();
		
		Process process;
		try {
			process = new ProcessBuilder(cmdOptions).start();
			InputStream is = process.getInputStream();
			InputStream es = process.getErrorStream();
			
			InputStreamReader isr = new InputStreamReader(is);
			BufferedReader br = new BufferedReader(isr);
			String line;

			while ((line = br.readLine()) != null) {
			  System.out.println(line);
			  builder.append(line);
			}
			
			//debugging
			br = new BufferedReader(new InputStreamReader(es));
			while ((line = br.readLine()) != null) {
				System.out.println("Error: "+ line);
			}

		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		return builder.toString();		
	}