问题
I have build contact manager app and When I try to run it I got following error
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$174(PlatformImpl.java:294)
at `enter code here`com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
at addressapp.PersonOverviewController.initialize(PersonOverviewController.java:52)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2548)
... 13 more
After that I searched where there the application stopped stopped within the initialize() block and setCellValueFactory() of my table view column. This is my controller code. Please tell me what is the matter of this code?
Controller
package addressapp;
import addressapp.Model.Person;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Label;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
public class PersonOverviewController implements Initializable {
@FXML
private TableView<Person> personTable;
@FXML
private TableColumn<Person, String> firstNameColumn;
@FXML
private TableColumn<Person, String> lastNameColumn;
@FXML
private Label firstNameLabel;
@FXML
private Label lastNameLabel;
@FXML
private Label streetLabel;
@FXML
private Label postalCodeLabel;
@FXML
private Label cityLabel;
@FXML
private Label birthdayLabel;
private AddressApp AddressApp;
public PersonOverviewController() {
}
@Override
public void initialize(URL url, ResourceBundle rb) {
firstNameColumn.setCellValueFactory(new PropertyValueFactory<>("firstName"));
lastNameColumn.setCellValueFactory(new PropertyValueFactory<>("lastName"));
}
public void setMainApp(AddressApp mainApp) {
this.AddressApp = mainApp;
personTable.setItems(mainApp.getPersonData());
}
}
Here my FXML
<?xml version="1.0" encoding="UTF-8"?>
<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<AnchorPane id="AnchorPane" prefHeight="484.0" prefWidth="584.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="addressapp.PersonOverviewController">
<children>
<Label fx:id="label" layoutX="126" layoutY="120" minHeight="16" minWidth="69" />
<SplitPane layoutX="-2.0" prefHeight="484.0" prefWidth="584.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<items>
<AnchorPane prefHeight="300.0" prefWidth="600.0">
<children>
<SplitPane dividerPositions="0.29797979797979796" layoutX="14.0" prefHeight="482.0" prefWidth="582.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<items>
<AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="160.0" prefWidth="100.0">
<children>
<TableView id="personTable" layoutX="-7.0" layoutY="40.0" prefHeight="480.0" prefWidth="170.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<columns>
<TableColumn id="firstNameColumn" prefWidth="75.0" text="First Name" />
<TableColumn id="lastNameColumn" prefWidth="83.0" text="Last Name" />
</columns>
<columnResizePolicy>
</columnResizePolicy>
</TableView>
</children>
</AnchorPane>
<AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="160.0" prefWidth="100.0">
<children>
<Label layoutX="25.0" layoutY="25.0" text="Person Details" AnchorPane.leftAnchor="5.0" AnchorPane.topAnchor="5.0" />
<GridPane layoutX="14.0" layoutY="42.0" AnchorPane.leftAnchor="5.0" AnchorPane.rightAnchor="5.0" AnchorPane.topAnchor="40.0">
<columnConstraints>
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
</columnConstraints>
<rowConstraints>
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
</rowConstraints>
<children>
<Label text="First Name" />
<Label text="Last Name" GridPane.rowIndex="1" />
<Label text="Street" GridPane.rowIndex="2" />
<Label text="City" GridPane.rowIndex="3" />
<Label text="Postal Code" GridPane.rowIndex="4" />
<Label text="Birthday" GridPane.rowIndex="5" />
<Label id="firstNameLabel" text="Label" GridPane.columnIndex="1" />
<Label id="lastNameLabel" text="Label" GridPane.columnIndex="1" GridPane.rowIndex="1" />
<Label id="streetLabel" text="Label" GridPane.columnIndex="1" GridPane.rowIndex="2" />
<Label id="postalCodeLabel" text="Label" GridPane.columnIndex="1" GridPane.rowIndex="3" />
<Label id="cityLabel" text="Label" GridPane.columnIndex="1" GridPane.rowIndex="4" />
<Label id="birthdayLabel" text="Label" GridPane.columnIndex="1" GridPane.rowIndex="5" />
</children>
</GridPane>
<Button layoutX="338.0" layoutY="441.0" mnemonicParsing="false" text="Delete" />
<Button layoutX="286.0" layoutY="441.0" mnemonicParsing="false" text="Edit.." />
<Button layoutX="232.0" layoutY="441.0" mnemonicParsing="false" text="New.." AnchorPane.rightAnchor="126.0" />
</children>
</AnchorPane>
</items>
</SplitPane>
</children></AnchorPane>
</items>
</SplitPane>
</children>
</AnchorPane>
回答1:
Your FXML file is using an id attribute, instead of the fx:id attribute on all the controls. Consequently, none of the @FXML-annotated fields are initialized by the FXMLLoader.
You need
<TableColumn fx:id="firstNameColumn" prefWidth="75.0" text="First Name" />
<TableColumn fx:id="lastNameColumn" prefWidth="83.0" text="Last Name" />
and similarly for all the other controls.
来源：https://stackoverflow.com/questions/36737653/fxmlloader-constructloadexception-occuered-when-app-gets-initialize