我用javafx构建了一个简单的程序，并且已经部署了应用程序以在IntelliJ(社区版(之外使用。我似乎无法弄清楚为什么当我尝试在 IDE.It 之外启动 exe 时没有调用该方法显示两个警报框，第一个说调用方法错误，第二个说我尝试从资源管理器打开 exe 后无法启动 JVM。
package sample;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.PasswordField;
import javafx.scene.control.TextField;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.StackPane;
import javafx.scene.control.Button;
import javafx.scene.paint.Color;
import javafx.scene.text.Font;
import javafx.scene.text.FontWeight;
import javafx.scene.text.Text;
import javafx.stage.Stage;
public class Main extends Application {
public static void main(String[] args) {
launch(args);
}
@Override
public void start(Stage primaryStage) throws Exception{
primaryStage.setTitle("Welcome");
primaryStage.setResizable(false);
primaryStage.show();
GridPane grid = new GridPane();
grid.setAlignment(Pos.CENTER);
grid.setHgap(10);
grid.setVgap(10);
grid.setPadding(new Insets(25, 25, 25, 25));
//Adding text labels and text fields
Text sceneTitle = new Text("Welcome");
sceneTitle.setId("welcome-text");
grid.add(sceneTitle, 0, 0,2, 1);
TextField userTextField = new TextField();
grid.add(userTextField, 1,1);
Label userName = new Label("User Name: ");
grid.add(userName, 0 ,1);
Label pw = new Label("Password: ");
grid.add(pw, 0,2);
PasswordField pwBox = new PasswordField();
grid.add(pwBox,1,2);
//grid lines for debugging
grid.setGridLinesVisible(false);
//grid lines for debugging
Button btn = new Button("Sign In");
HBox hbBtn = new HBox(10);
hbBtn.setAlignment(Pos.BOTTOM_RIGHT);
hbBtn.getChildren().add(btn);
grid.add(hbBtn, 1,4);
final Text actionTarget = new Text();
grid.add(actionTarget,1,6);
btn.setOnAction(e -> {actionTarget.setText("Sign In button
Pressed");});
actionTarget.setId("actiontarget");
Scene scene = new Scene(grid, 300, 275);
primaryStage.setScene(scene);
//Initialize sytlesheets variable
scene.getStylesheets().add(Main.class.getResource("Login.css").toExternalForm());
primaryStage.show();
}
}
这是我的控制器类(哈哈(
package sample;
public class Controller {
}
最后...我的 fxml
<?import javafx.geometry.Insets?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<GridPane fx:controller="sample.Controller"
xmlns:fx="http://javafx.com/fxml" alignment="center" hgap="10" vgap="10">
</GridPane>
我必须帮助的最后一件事是在这里，但我不确定如何阅读它以找到问题的根源......
C:UsersJoopIdeaProjectsHellooutartifactsJavaFXAppbundles>java -jar "JavaFXApp.jar"
Exception in Application start method
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.launcher.LauncherHelper$FXHelper.main(Unknown Source)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$154(LauncherImpl.java:182)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
at sample.Main.start(Main.java:64)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$161(LauncherImpl.java:863)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$174(PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$172(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$173(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
... 1 more
Exception running application sample.Main
我不知道如何阅读它以找到问题的根源......
关键部分是这样的：
Caused by: java.lang.NullPointerException
at sample.Main.start(Main.java:64)
这表明主.java，第 64 行抛出了NullPointerException.因此，由于以下行，将引发异常：
scene.getStylesheets().add(Main.class.getResource("Login.css").toExternalForm());
具体来说，Main.class.getResource("Login.css")很可能返回 null。这将是因为它找不到Login.css，几乎可以肯定是因为您没有将其包含在构建中(因此您无法在 IDE 外部成功运行它。