Question

有人可以告诉我，为什么一切正常，除了在表格中显示ID？数据类型有问题吗？

有一个代码，我将数据放入tableView。

public class TabulkaProdukty {

    private final FlowPane panelTabulky;
    public final TableView<Produkty> tabulkaTabulkaProdukty;
    public ObservableList<Produkty> dataTabulkaProdukty;
    public static Connection connection;
    private static Statement statement;

    public TabulkaProdukty() {
        panelTabulky = new FlowPane();
        tabulkaTabulkaProdukty = new TableView<>();
        panelTabulky.getChildren().add(tabulkaTabulkaProdukty);
        tabulkaTabulkaProdukty.setEditable(true);
        try {
            connection = DriverManager.getConnection("jdbc:sqlite:produkty");
            statement = connection.createStatement();
            statement.executeUpdate("create table if not exists produkty(id INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE, nazev TEXT NOT NULL, popis TEXT NOT NULL, typ TEXT NOT NULL, cena TEXT NOT NULL);");
            dataTabulkaProdukty = FXCollections.observableArrayList();
            ResultSet rs = connection.createStatement().executeQuery("SELECT * FROM produkty;");
            while (rs.next()) {
                dataTabulkaProdukty.add(new Produkty(rs.getInt("id"), rs.getString("nazev"), rs.getString("popis"), rs.getString("typ"), rs.getString("cena")));
            }

            // VECI V TABULCE
            TableColumn idCol = new TableColumn("id");
            idCol.setMinWidth(50);
            idCol.setCellValueFactory(
                    new PropertyValueFactory<>("id"));

            TableColumn nazevCol = new TableColumn("Název");
            nazevCol.setMinWidth(100);
            nazevCol.setCellValueFactory(
                    new PropertyValueFactory<>("nazev"));

            TableColumn popisCol = new TableColumn("Popis");
            popisCol.setMinWidth(200);
            popisCol.setCellValueFactory(
                    new PropertyValueFactory<>("popis"));

            TableColumn typCol = new TableColumn("Typ");
            typCol.setMinWidth(50);
            typCol.setCellValueFactory(
                    new PropertyValueFactory<>("typ"));

            TableColumn cenaCol = new TableColumn("Cena");
            cenaCol.setMinWidth(50);
            cenaCol.setCellValueFactory(
                    new PropertyValueFactory<>("cena"));

            tabulkaTabulkaProdukty.setColumnResizePolicy(TableView.CONSTRAINED_RESIZE_POLICY);
            tabulkaTabulkaProdukty.setItems(null);
            tabulkaTabulkaProdukty.setItems(dataTabulkaProdukty);
            tabulkaTabulkaProdukty.getColumns().addAll(idCol, nazevCol, popisCol, typCol, cenaCol);

        } catch (Exception e) {
            Alert alert = new Alert(Alert.AlertType.ERROR);
            alert.setTitle("Error dialog");
            alert.setHeaderText("Chyba databáze");
            alert.setContentText("Nepovedlo se načíst data z databáze.");
            alert.showAndWait();
        }

    }

有一个Class Produkty

public class Produkty implements Serializable {

        private final SimpleIntegerProperty id;
        private final SimpleStringProperty nazev;
        private final SimpleStringProperty popis;
        private final SimpleStringProperty typ;
        private final SimpleStringProperty cena;
        public NaMinimum panelNaMinimum;

        public Produkty(int pID, String pNazev, String pPopis, String pTyp, String pCena) {
            this.id = new SimpleIntegerProperty(pID);
            this.nazev = new SimpleStringProperty(pNazev);
            this.popis = new SimpleStringProperty(pPopis);
            this.typ = new SimpleStringProperty(pTyp);
            this.cena = new SimpleStringProperty(pCena);
        }

        public int getIDProduktu() {return id.get();}
        public void setIDProduktu(int pID) {id.set(pID);} 
        public String getNazev() {return nazev.get();}
        public void setNazev(String pNazev) {nazev.set(pNazev);}
        public String getPopis() {return popis.get();}
        public void setPopis(String pPopis) {popis.set(pPopis);}
        public String getTyp() {return typ.get();}
        public void setTyp(String pTyp) {typ.set(pTyp);}
        public String getCena() {return cena.get();}
        public void setCena(String pCena) {cena.set(pCena);}

    }

我真的很感激任何解决的建议。

Answer 1

PropertyValueFactory根据构造函数参数查找方法，而不是字段。根据getter的名称，参数应为"IDProduktu"或"iDProduktu"：

idCol.setCellValueFactory(new PropertyValueFactory<>("IDProduktu"));

请注意，如果没有属性getter方法TableView，则无法观察到属性中的任何更改。在这种情况下，您可以使用普通字段获得相同的效果。要观察更改，您需要提供一个名为<property>Property的方法，其中<property>是一个占位符，用于传递给PropertyValueFactory的构造函数的属性名称，例如如果您使用"id"作为构造函数参数：

public IntegerProperty idProperty() {
    return id;
}

Answer 2

最好知道你对此做了什么，但我的猜测是id的整数值没有显示为字符串，因此其行为方式与其他参数不同。 / p>

来自DB的ID不显示

2 个答案: