Checking username and passwords against MySQL is returning blank

I am doing username and password check against MySQL database but somehow my code is returning none even for the base case (email does not exist). I hash my passwords on the server side. What should I fix in this case?

package GUI_755;
import java.sql.*;
import nonGUI_755.AES;
public class test {
public static void main(String args[]) throws Exception {
System.out.println(loginResponse("jordan30@bulls.edu","JordanTheGoat3098"));
}
/* The method handles the login's request from the user */
public static String loginResponse(String email, String password) throws Exception{
String returnStatement = "";
Connection connection = null;
connection = establishConnection();
/* Similar to the code above, we check whether the email and password match to those we have in the database */
final String queryCheck = "SELECT * from usersdata WHERE email = ?";		
final PreparedStatement ps = connection.prepareStatement(queryCheck);
ps.setString(1, email);
final ResultSet resultSet = ps.executeQuery();
try {
/* First, if we cannot find the user's email, we return this statement */
if(email.equals(resultSet.getString("email"))) {
/* Second, if we can find the email but the password do not match then we return that the password is incorrect */
String hashedPasswordInput = AES.doHash(password, resultSet.getObject("password").toString().split("\t")[1]);
if(hashedPasswordInput.equals(resultSet.getObject("password").toString().split("\t")[0])) {
returnStatement = "LoginFailure The password that you entered is incorrect. Please try again!";
connection.close();
}
else {
returnStatement = "LoginSuccess You are logged in!";
}
}
else {
connection.close();
returnStatement = "LoginFailure We cannot find any account associated with that email. Please try again!";
}
}catch(Exception e) {}
return returnStatement;
}
/* This method will connect to MySQL database >> userdata */
public static Connection establishConnection(){
try {
Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql://localhost/userdata","root","");
return connection;
}catch(Exception e)
{return null;}
}
}

You need to check if your ResultSet resultSet is returning some rows. For that, you should use next() method of ResultSet. You can use if (resultSet.next() if you are interested in only first row (like your case here) or while (resultSet.next()) if you want to loop over the returned result rows (not your case).

So to put it together:

final String queryCheck = "SELECT * from usersdata WHERE email = ?";        
final PreparedStatement ps = connection.prepareStatement(queryCheck);
ps.setString(1, email);
final ResultSet resultSet = ps.executeQuery();
if (resultSet.next()) {
/* First, if we cannot find the user's email, we return this statement */
if(email.equals(resultSet.getString("email"))) {
/* Second, if we can find the email but the password do not match then we return that the password is incorrect */
String hashedPasswordInput = AES.doHash(password, resultSet.getObject("password").toString().split("\t")[1]);
if(hashedPasswordInput.equals(resultSet.getObject("password").toString().split("\t")[0])) {
// dont do it here
// returnStatement = "LoginFailure The password that you entered is incorrect. Please try again!";
//  connection.close();
}
else {
returnStatement = "LoginSuccess You are logged in!";
}
}
else {
// don't do it here
// connection.close();
// returnStatement = "LoginFailure We cannot find any account associated with that email. Please try again!";
}
}