Question

I was trying to create a very simple app where at loading the main window the program connects to the DB.

If I comment the part of the connection to the DB it works fine. The app shows no error, throws no exception, so I cannot figure out what’s wrong. I post my code:

public final class Database {
    private final String dbURL = "jdbc:oracle:thin:@" + dbHost + ":" + dbPort + ":" + dbService;
    private final String dbDriver = "oracle.jdbc.driver.OracleDriver";
    private Connection connection = null;

    public Database() {
        try {
            System.out.println("Aqui 1");
            Class.forName(dbDriver);
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(Database.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    private void connect() {
        System.out.println("Dentro");
        try {
            connection = DriverManager.getConnection(dbURL, dbUser, dbPass);
        } catch (SQLException ex) {
            Logger.getLogger(Database.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    private void disconnect() {
        try {
            connection.close();
        } catch (SQLException ex) {
            Logger.getLogger(Database.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public void numeroErrores(String dependencia){
        System.out.println("Hola");
        connect();
        disconnect();
        System.out.print("Adios");
    }
}

the dbUser, dbPass, dbHost, dbPort, dbService are set to their correct value, I’ve checked and rechecked them, also I am sure I’ve added the correct jar file of the oracle-jdbc. It kind of hangs (I say kind of ’cause no error no nothing is shown but the System.out.println I put there) when calling the connect() method.

Any idea?

Answer 1

There are not enough debug prints or catch statements
Try catching both general Exception and Throwable, see if that adds data
If you dont have a debugger, add debug prints on every line so you know exactly where you are
If you have the ojdbc6.jar, try adding this right before DriverManager.getConnection:

DriverManager.registerDriver(new oracle.jdbc.OracleDriver());

just to make sure