Best practices for connecting to DB

Question

Hi,
I am having 3 different java classes which will contact the DB for getting the data from the table. I wrote a separate java class for DB connection like this :
public class DBConnection {
private Connection con;
public Connection getConnection() {
try {
Class.forName("org.apache.derby.jdbc.ClientDriver");
con = DriverManager.getConnection("jdbc:derby://localhost:1527/StrutsDB", "username", "password");
} catch (SQLException ex) {
Logger.getLogger(DBConnection.class.getName()).log(Level.SEVERE, null, ex);
} catch (ClassNotFoundException ex) {
Logger.getLogger(DBConnection.class.getName()).log(Level.SEVERE, null, ex);
return con;
How to use this single connection object in all of the 3 classes? What are all the ways of doing so?
Is there any best practices for connecting to DB?
Thanks in advance,

Answer 1

The problem with "best practice" is it really depends on your situation. If you are creating a single user, desktop application then what you are doing will work but would be more efficient if the connection was declared as static and you used the singleton pattern.
public class DBConnection {
    private static final Connection con;
    private DBConnection() {
        try {
            Class.forName("org.apache.derby.jdbc.ClientDriver");
            con = DriverManager.getConnection("jdbc:derby://localhost:1527/StrutsDB", "username", "password");
        } catch (SQLException ex) {
            Logger.getLogger(DBConnection.class.getName()).log(Level.SEVERE, null, ex);
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(DBConnection.class.getName()).log(Level.SEVERE, null, ex);
    public static Connection getConnection() {
        return con.
}The private constructor guarantees only one instance of the class will be created (since you can't use 'new' to create one) and initialized the database connection. Then any other object that require a connection simply call DBConnection.getConnection() and they will get the same database connection each time.
Note that this is a little simplistic and is not thread safe. If your classes will be executing on different threads you will need a more sophisticated approach. You will also need to make sure you commit or rollback any transactions when done or the next time you get the connection you may be in the middle of an existing transaction.