Conexão Oracle com Java

private String drv;
private String url;
private String user;
private String passwd;
private Connection conn;	
private Statement stmt;

public boolean conecta(){
	boolean result = true;						
	try {
		Class.forName(drv);
	    conn = DriverManager.getConnection(url, user, passwd);
		
	}catch(ClassNotFoundException erroClass) {
		mensagemErro(erroClass.getMessage());
		result = false;
	} catch(SQLException erroSQL) {
	    mensagemErro(erroSQL.getMessage());
	    result = false;
	  }
	  return result;
}

public void desconecta() {
	boolean result = true;
	
	try {
		conn.close();
	}catch(SQLException erroSql) {
		mensagemErro(erroSql.getMessage());
		result = false;
	}
}

public int regCount(String qry) {
	int result = 0;
	
	try {
		stmt = conn.createStatement();
		ResultSet rs = stmt.executeQuery(qry);
		rs.next();
		result = rs.getInt(1);
		stmt.close();
	}catch(SQLException sqlex) {
		mensagemErro(sqlex.getMessage());			
	}
	return result;
}	

public void getColumn(String qry, String[] reg) {
	try {
		Statement stmt = conn.createStatement();
		ResultSet rs = stmt.executeQuery(qry);
		rs.next();
		for(int i = 1; i <= reg.length; i++)
			reg[i - 1] = "" + rs.getString(i);
		stmt.close();
	}catch(SQLException sqlex) {
		mensagemErro(sqlex.getMessage());
	}
}

public void getColumn(String qry, String [][] reg, int regs ) {
	try {
		int lin = 0;
		stmt = conn.createStatement();
		ResultSet rs = stmt.executeQuery(qry);
		while(rs.next()) {
			for (int i = 0; i < regs; i ++) {
				reg[lin][i] = "" + rs.getString(i + 1);
			}
			lin ++;
		}
	}catch(SQLException sqlex) {
		mensagemErro(sqlex.getMessage());
	}	
}

public String getDrv() {
	return drv;
}

public void setUrl(String valor) {
	url = valor;
}

public void setUser(String valor) {
	user = valor;
}

public void setPasswd(String valor) {
	passwd = valor;
}

private void mensagemErro(String msg) {
	JOptionPane.showMessageDialog(null, msg, "Erro", JOptionPane.ERROR_MESSAGE);
}

public void conectar(String login, String senha) {
        try {
            Class.forName("oracle.jdbc.driver.OracleDriver");
            con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe", login, senha);
            stDados = con.createStatement();
            System.err.println("conectou");
        } catch (ClassNotFoundException ex) { 
            ex.printStackTrace();
        } catch (SQLException ex) {
            ex.printStackTrace();
        }
    }