public Contact() {

}
public Contact (String name, String email, String address, int phone) {
    this.name=name;
    this.email=email;
    this.address=address;
    this.telephoneNumber=phone;
}
//Getters e Setters
 ...
}


    public class ContactDAO {
    private Connection con;


    public Connection getConnection() {
    return con;
    }

    public ContactDAO() {
      ConnectionFactory conF = new ConnectionFactory();
      con=conF.getBDConnection();
    }

   public void addClient(Contact contact) {
    String sql= "INSERT INTO contatos" + "(nome,email,endereco,telefone)" +
   "values (?,?,?,?)";

    try {
        PreparedStatement stmt= con.prepareStatement(sql);


        stmt.setString(1,contact.getName());
        stmt.setString(2,contact.getEmail());
        stmt.setString(3,contact.getAddress());
        stmt.setInt(4,contact.getTelephoneNumber());


        stmt.executeUpdate();
        stmt.close();
    } catch (SQLException sqle) {
        sqle.printStackTrace();
    } finally {
        try {
            con.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}
}


public class ConnectionFactory {


public Connection getBDConnection() {
    Connection con = null;
    System.out.println("Testing access to BD MySQLn");

    try {
        Class.forName("com.mysql.jdbc.Driver");
        con = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb","root", "");
        System.out.println("Connection successful!!!");
    } catch (ClassNotFoundException cnfe){
        cnfe.printStackTrace();
        System.out.println("ClassNotFoundException");
    } catch (SQLException sqle) {
        sqle.printStackTrace();
        System.out.println("SQLException");
    }
    return con;
}

public void closeConnection(Connection con) {
    try {
     con.close();
     System.out.println("n Connection successfully close!!!");
    }
    catch (SQLException sqle) {
        System.out.println("SQLException");
    }
  }
}