try {

        PreparedStatement stm;
        stm = connex.getConexao().prepareStatement("INSERT INTO onibus "
                + "(ano, chassi, placa, numeroOnibus, tipoVeiculo) "
                + "VALUES (?,?,?,?,?);");

        stm.setInt(1, onibus.getAno());
        stm.setString(2, onibus.getChassi());
        stm.setString(3, onibus.getPlaca());
        stm.setInt(4, onibus.getNumeroOnibus());
        stm.setString(5, onibus.getTipoVeiculo());

        stm.execute();

        JOptionPane.showMessageDialog(null, "Onibus Inserido Com Sucesso!");

    } catch (HeadlessException | SQLException e) {

        JOptionPane.showMessageDialog(null, "Erro ao inserir Onibus!nERRO");
        e.printStackTrace();

    } finally {
        connex.desconecta();
    }


}

public Statement stm;
    public ResultSet rst;
private final String driver = "org.postgresql.Driver";
private final String url = "jdbc:postgresql://localhost:5432/CONI-VP";
private final String usuario = "postgres";
private final String senha = "root";
 Connection conexao = null;

public Conexao(){
    try {
        Class.forName(driver);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public Conexao(Statement stm, ResultSet rst) {
    this.stm = stm;
    this.rst = rst;
}

public Connection getConexao(){
    if(conexao == null){
        try {
            conexao = DriverManager.getConnection(url, usuario, senha);
            conexao.setAutoCommit(false);
        } catch (SQLException e) {
        }
    }
    return conexao;
}

public void desconecta(){
    try {
        conexao.close();
            } catch (SQLException e) {
    }
    conexao = null;
}


}

o.setAno(Integer.parseInt(jFormatted_ano.getText()));
        o.setNumeroOnibus(Integer.parseInt(jFormatted_numOnibus.getText()));
        o.setChassi(jTextField_tipo.getText());
        o.setPlaca(jTextField_placa.getText());
        o.setTipoVeiculo(jTextField_tipo.getText());
    }

    o.getCodOnibus();
    o.setAno(Integer.parseInt(jFormatted_ano.getText()));
    o.setNumeroOnibus(Integer.parseInt(jFormatted_numOnibus.getText()));
    o.setChassi(jTextField_chassi1.getText());
    o.setPlaca(jTextField_placa.getText());
    o.setTipoVeiculo(jTextField_tipo.getText());;
            dao.inserirOnibus(o);

    jFormatted_ano.setText("");
    jFormatted_numOnibus.setText("");
    jTextField_tipo.setText("");
    jTextField_placa.setText("");
    jTextField_chassi1.setText("");