public class UserVerification {

  private static Connection connect = null;
  private static String host="localhost";
  private static String database="database";
  private static String username="root";
  private static String password="xxxx";


  public static Connection getConnection(){

        if(connect ==null){
            try{
             Class.forName("com.mysql.jdbc.Driver");
              String conn_string="jdbc:mysql://"+host+"/"+database;
              Connection connect = DriverManager.getConnection(conn_string,username,password);
              return connect;
            }catch(Exception ex){
                return null;
                //ex.printStackTrace();
            }
        }else{
            return connect;
        }
    }

  public User checkUser(String user,String password){

      String sql="SELECT * FROM OFFICER  WHERE OUSERNAME='?' AND PASSWORDHASH=?";
      User u=null;
        try( Connection connect = getConnection();
             PreparedStatement pstmt = connect.prepareStatement(sql);
            ){
             pstmt.setString(1,user);
             pstmt.setString(2,HashGenerator.getMD5Hash(password));
             try (ResultSet rs = pstmt.executeQuery();){
               while(rs.next()){
                  String uname=rs.getString("USERNAME");
                  String pass=rs.getString("PASSWORDHASH");
                  u = new User(uname,pass);
                  break;
              }
             }
        }catch(SQLException ex){
            ex.printStackTrace();
        }
        return u;
  }
}