Api Post Method

public String apiMethod_POST()
     {	
	String foutput = "";
	  try 
	     {
		URL url = new URL(uri);
		System.out.println("API URL : " + url);
		
		HttpURLConnection conn = (HttpURLConnection) url.openConnection();
		conn.setDoOutput(true);
		conn.setRequestMethod("POST");
		conn.setRequestProperty("Content-Type", "application/json");
		    if(authToken!=null && authToken.length()>0)
		      {
			      conn.setRequestProperty("X-Auth-Token",authToken);
		      }
		System.out.println("JSON sent in input is .........>>>>>>>" + json);
		
		OutputStream os = conn.getOutputStream();
		os.write(json.getBytes());
		os.flush();
		
		int Responsecode = conn.getResponseCode();
			
		String ResponseCode=String.valueOf(Responsecode);
		String ResponseMessage = conn.getResponseMessage();
		String LoginContentType = conn.getContentType();
		
		if (conn.getResponseCode() != 200) 
		  {
			  throw new RuntimeException("Failed : HTTP Error code : " + conn.getResponseCode());
		  }
			
		BufferedReader br = new BufferedReader(new InputStreamReader((conn.getInputStream())));

		String output ;
			
		while ((output = br.readLine()) != null) 
		  {
			 foutput = foutput + output;
		  }
		} 
		catch (MalformedURLException e) 
		  {
			  e.printStackTrace();
		  } 
		catch (IOException e) 
		  {
			  e.printStackTrace();
		  }
		  
		return foutput;
	}