JDBC properties file

I am trying to configure JDBC property via a Projerties file.
This is original.

public class JDBCLibrary{

  private static final String DRIVER= "com.mysql.jdbc.Driver";
  private static final String DB_URL = "jdbc:mysql://webdev.apl.jhu.edu/library";
  private static final String USER = "lib_user";
  private static final String PASSWORD = "jhu481";

  private Connection conn;

  public JDBCLibrary() throws ClassNotFoundException, SQLException{
    conn = createConnection();
  }

  private Connection createConnection() throws ClassNotFoundException, SQLException{
    Class.forName(DRIVER) ;
    Connection conneciton = DriverManager.getConnection(DB_URL, USER, PASSWORD) ;

    return conneciton;
  }

  public synchronized void excuteQuery() throws SQLException{
    final String QUERY =
        "SELECT TITLE, AUTHOR FROM BOOKS";
    Statement statement = conn.createStatement() ;
    ResultSet results = statement.executeQuery(QUERY);
    System.out.println("Books: ");

    while(results.next()){
      System.out.println("Book: "+results.getString(1) );
      System.out.println("Author: "+results.getString(2));
    }
    results.close();
    statement.close();
  }


This is updated one.
--------------------------------------
 public class JDBCBook{

   private static String DRIVER;
   private static String DB_URL;
   private static String USER;
   private static String PASSWORD;
   
   public JDBCBook() throws ClassNotFoundException, SQLException{
     conn = createConnection();

     bookList = new ArrayList();
   }

   private Connection createConnection() throws ClassNotFoundException, SQLException{
     try {
       Properties props = new Properties();
       props.load(this.getClass().getResourceAsStream("/config/jdbc.properties"));
       DRIVER = props.getProperty("jdbc.driver");
       USER = props.getProperty("jdbc.user");
       DB_URL = props.getProperty("jdbc.url");
       PASSWORD = props.getProperty("jdbc.password");
     }catch (IOException e) {
       System.out.println(e);
     }

     Class.forName(DRIVER) ;
     Connection conneciton = DriverManager.getConnection(DB_URL, USER, PASSWORD) ;

     return conneciton;
   }
----------------------------------
but, I am having these errors.

Exception in thread "main" java.lang.NullPointerException
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:140)
        at dkim18.jdbc.JDBCBook.createConnection(JDBCBook.java:46)
        at dkim18.jdbc.JDBCBook.<init>(JDBCBook.java:29)
        at dkim18.jdbc.JDBCBook.main(JDBCBook.java:89)