If I use a singleton class for a database connection, can one user close the connection for everybody?

Question

I wrote a singleton class for obtaining a database connection.

Now my question is this: assume that there are 100 users accessing the application. If one user closes

Answer 1

Below code is a working and tested Singleton Pattern for Java.

public class Database {

    private static Database dbIsntance;
    private static Connection con ;
    private static Statement stmt;


    private Database() {
      // private constructor //
    }

    public static Database getInstance(){
    if(dbIsntance==null){
        dbIsntance= new Database();
    }
    return dbIsntance;
    }

    public  Connection getConnection(){

        if(con==null){
            try {
                String host = "jdbc:derby://localhost:1527/yourdatabasename";
                String username = "yourusername";
                String password = "yourpassword";
                con = DriverManager.getConnection( host, username, password );
            } catch (SQLException ex) {
                Logger.getLogger(Database.class.getName()).log(Level.SEVERE, null, ex);
            }
        }

        return con;
    }

While getting Connection in any Class simply use below line

Connection con = Database.getInstance().getConnection();

Hope it may help :)