How to fetch session of JSON Object?

 public static String getSessionIdJSONObject(String userName, String password, HashMap<String, String> lookupData) {

String methodName = "getSessionIdJSONObject";

LOGGER.debug(CLASS_NAME + "/" + methodName + "; userName = " + userName + "; password = " + password);

System.out.println(CLASS_NAME + "/" + methodName + "; userName = " + userName + "; password = " + password);

String WS_URL = null;

URL url = null;

String retVal = "SUCCESS";

StringBuffer response = null;

OutputStream os = null;

BufferedReader in = null;

try {

String webServiceParams = "{\"UserName\":\"" + userName + "\"" + " , \"Password\":\"" + password + "\"}";

System.out.println("webServiceParams : " + webServiceParams);

WS_URL = lookupData.get("SessionIdURL");

System.out.println("WebService URL :" + WS_URL);

url = new URL(WS_URL);

                        //url = new URL(null, WS_URL, new sun.net.www.protocol.https.Handler());

HttpsURLConnection postConnection = (HttpsURLConnection) url.openConnection();

postConnection.setRequestMethod("POST");

postConnection.setRequestProperty("Content-Type", "application/json");

postConnection.setDoOutput(true);

os = postConnection.getOutputStream();

os.write(webServiceParams.getBytes());

int responseCode = postConnection.getResponseCode();

System.out.println("POST Response Code :  " + responseCode);

System.out.println("POST Response Message : " + postConnection.getResponseMessage());

if (responseCode == 200) { // success

in = new BufferedReader(new InputStreamReader(postConnection.getInputStream()));

String inputLine;

response = new StringBuffer();

while ((inputLine = in.readLine()) != null) {

response.append(inputLine);

}

// print result

System.out.println("JSON object is : " + response.toString());

LOGGER.debug("JSON object is : " + response.toString());

} else {

retVal = "FAIL";

System.out.println("Return value is : " + retVal);

System.out.println("POST NOT WORKED");

LOGGER.debug("Return value is : " + retVal);

LOGGER.debug("POST NOT WORKED");

}

}

catch (Exception e) {

System.out.println("Exception is : " + e.getMessage());

LOGGER.error("Exception is : " + e.getMessage());

e.printStackTrace();

} // End of Catch block

finally {

closeIOFile(os, in);

}

System.out.println("Return value is : " + retVal);

LOGGER.debug("Return value is : " + retVal);

System.out.println("Exiting from the method : " + methodName);

LOGGER.debug("Exiting from the method : " + methodName);

return response.toString();

}

NOTE :  

Ex: SessionIdURL = "https://oimsailpointpedia.blogspot.com/search/label/Java";