JavaFX使用fxml打开新窗口问题
我正在开发一个密码管理程序。在此程序中打开新窗口时,它会在JavaFX使用fxml打开新窗口问题,java,javafx,Java,Javafx,我正在开发一个密码管理程序。在此程序中打开新窗口时,它会在addEntry()鼠标单击事件上引发异常。我有一个打开主窗口的Main类(使用sample.fxml)和一个管理打开新窗口的Controller类(使用addNewEntryDialog.fxml)。这是我的密码: Main.java package sample; import javafx.application.Application; import javafx.fxml.FXML; import javafx.fxml.FX
addEntry()
鼠标单击事件上引发异常。我有一个打开主窗口的Main
类(使用sample.fxml
)和一个管理打开新窗口的Controller
类(使用addNewEntryDialog.fxml
)。这是我的密码:
Main.java
package sample;
import javafx.application.Application;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Modality;
import javafx.stage.Stage;
import java.io.IOException;
public class Main extends Application {
@Override
public void start(Stage primaryStage) throws Exception{
Parent root = FXMLLoader.load(getClass().getResource("/sample.fxml"));
primaryStage.setTitle("Password Manager");
primaryStage.setScene(new Scene(root, 800, 600));
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
Controller.java
package sample;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.stage.Stage;
import javafx.stage.StageStyle;
import java.io.IOException;
import java.net.URL;
import java.sql.*;
import java.util.ResourceBundle;
public class Controller implements Initializable {
public ObservableList<Data> data;
public TableView dbTable;
public TableColumn siteColumn, usernameColumn, passwordColumn;
public ToggleButton showPasswordToggle;
@Override
public void initialize(URL location, ResourceBundle resources) {
fillTable();
}
public void fillTable(){
data = FXCollections.observableArrayList();
String query = "SELECT * FROM accounts";
try {
Connection connection = connectToDatabase();
ResultSet resultSet = connection.createStatement().executeQuery(query);
while (resultSet.next()) {
data.add(new Data(resultSet.getString(1), resultSet.getString(2), resultSet.getString(3)));
}
siteColumn.setCellValueFactory(new PropertyValueFactory("site"));
usernameColumn.setCellValueFactory(new PropertyValueFactory("username"));
passwordColumn.setCellValueFactory(new PropertyValueFactory("password"));
dbTable.setItems(data);
} catch (SQLException e) {
e.printStackTrace();
}
}
@FXML
public void addEntry() throws IOException {
Stage stage = new Stage();
Parent root = FXMLLoader.load(getClass().getResource("/addEntryDialog.fxml"));
stage.setTitle("Add new entry");
stage.setScene(new Scene(root, 800, 600));
stage.show();
}
查看您的
addEntryDialog.fxml
文件。此视图的控制器有以下定义:
<Pane ... fx:controller="sample.Controller>
那么问题出在哪里呢?调用addEntry()方法(鼠标单击事件)时会出现许多异常错误,因此请将堆栈跟踪添加到问题中。您没有包含sample.fxml/addEntryDialog.fxml文件或实际的错误消息/堆栈跟踪,因此无法确定问题出在哪里。您应该创建一个实际可运行的应用程序片段,因此重构数据库代码并包括Data domain对象。不过,仅使用堆栈跟踪将非常有帮助。好的,我将添加堆栈跟踪和fxml文件。我只需要addEntryView.fxml。单击“添加”按钮添加新表项时,siteColumn是表的一部分。所以我只需要从一个方法打开一个新窗口,我不关心表列。@UmbertoPalazzini没错,但您已经将sample.Controller
定义为addEntryView
对话框的控制器。这就是它抛出空指针异常的原因。创建新窗口涉及为其创建控制器,控制器被创建并在初始化过程中抛出NPE,因为addEntryView
上没有列。
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<Pane prefHeight="600.0" prefWidth="800.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
<children>
<TableView fx:id="dbTable" layoutX="4.0" layoutY="85.0" prefHeight="505.0" prefWidth="790.0">
<columns>
<TableColumn fx:id="siteColumn" prefWidth="263.0" text="Site" />
<TableColumn fx:id="usernameColumn" prefWidth="263.0" text="Username" />
<TableColumn fx:id="passwordColumn" prefWidth="263.0" text="Password" />
</columns>
</TableView>
<GridPane layoutX="14.0" layoutY="27.0" prefHeight="25.0" prefWidth="263.0">
<columnConstraints>
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" />
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" />
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" />
</columnConstraints>
<rowConstraints>
<RowConstraints minHeight="10.0" vgrow="SOMETIMES" />
</rowConstraints>
<children>
<Button fx:id="addNewEntry" layoutX="14.0" layoutY="14.0" mnemonicParsing="false" onMouseClicked="#addEntry" text="Add.." GridPane.columnIndex="0" />
<Button fx:id="removeEntry" layoutX="83.0" layoutY="14.0" mnemonicParsing="false" text="Remove.." GridPane.columnIndex="1" />
<Button fx:id="editEntry" layoutX="178.0" layoutY="14.0" mnemonicParsing="false" text="Edit.." GridPane.columnIndex="2" />
</children>
</GridPane>
<ToggleButton fx:id="showPasswordToggle" layoutX="671.0" layoutY="27.0" mnemonicParsing="false" text="Show Password" />
</children>
</Pane>
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$ClickGenerator.postProcess(Scene.java:3470)
at javafx.scene.Scene$ClickGenerator.access$8100(Scene.java:3398)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3766)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:352)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:275)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:388)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:387)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
at com.sun.glass.ui.gtk.GtkApplication.lambda$null$49(GtkApplication.java:139)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1771)
... 31 more
Caused by: javafx.fxml.LoadException:
/home/umberto/passwordManager/out/production/passwordManager/addEntryDialog.fxml
at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2601)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2579)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3214)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097)
at sample.Controller.addEntry(Controller.java:58)
... 41 more
Caused by: java.lang.NullPointerException
at sample.Controller.loadTableData(Controller.java:45)
at sample.Controller.initialize(Controller.java:30)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2548)
... 49 more
<Pane ... fx:controller="sample.Controller>