代码中有问题，无法解决可以帮助我
import javafx.application.Application;
import javafx.event.ActionEvent;``
import javafx.stage.Stage;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.scene.paint.Color;
import java.util.Scanner;
public class Main extends Application {
public static double Price;
private static Double Qua;
private static int Num;
private static double cq;
private static String FirstName;
private static String LastName;
public static void main(String[] args)
{
launch(args);
CQ n=new CQ();
System.out.print("First Name: ");
n.FirstName=FirstName;
System.out.print("Last Name : ");
n.LastName=LastName;
System.out.print("Phone Number: ");
n.Num=Num;
System.out.print("Quantity: ");
n.Qua=Qua;
System.out.print("Price : ");
n.Price=Price;
n.Printinformation();
n.cq=cq;
}
@Override
public void start(Stage primaryStage) {
Group root=new Group();
Scene scene = new Scene(root,600,600,Color.BLANCHEDALMOND);
Label lab1=new Label("First Name");
lab1.setLayoutX(300);
lab1.setLayoutY(50);
Label lab2=new Label("Last Name");
lab2.setLayoutX(50);
lab2.setLayoutY(50);
Label lab3=new Label("Number Phone");
lab3.setLayoutX(50);
lab3.setLayoutY(100);
Label lab4=new Label("Quntity");
lab4.setLayoutX(300);
lab4.setLayoutY(100);
Label lab5=new Label("Price Press");
lab5.setLayoutX(50);
lab5.setLayoutY(150);
Label lab6=new Label("");
lab6.setLayoutX(300);
lab6.setLayoutY(150);
TextField txtname=new TextField();
FirstName=String.valueOf(txtname.toString());
txtname.setLayoutX(300);
txtname.setLayoutY(70);
TextField txtname2=new TextField();
LastName=String.valueOf(txtname2.toString());
txtname2.setLayoutX(50);
txtname2.setLayoutY(70);
TextField txtname3=new TextField();
Num=Integer.valueOf(txtname3.getText());
txtname3.setLayoutX(50);
txtname3.setLayoutY(120);
TextField txtname4=new TextField();
Qua=Double.valueOf(txtname4.getText());
txtname4.setLayoutX(300);
txtname4.setLayoutY(120);
TextField txtname5=new TextField();
Price =Double.valueOf(txtname5.getText());
txtname5.setLayoutX(50);
txtname5.setLayoutY(170);
TextField txtname6=new TextField();
txtname6.setLayoutX(300);
txtname6.setLayoutY(170);
root.getChildren().add(txtname);
root.getChildren().add(txtname2);
root.getChildren().add(txtname3);
root.getChildren().add(txtname4);
root.getChildren().add(txtname5);
root.getChildren().add(txtname6);
root.getChildren().add(lab1);
root.getChildren().add(lab2);
root.getChildren().add(lab3);
root.getChildren().add(lab4);
root.getChildren().add(lab5);
root.getChildren().add(lab6);
Button btn=new Button("Click Her");
btn.setLayoutX(50);
btn.setLayoutY(200);
root.getChildren().add(btn);
primaryStage.setTitle("Olive Press");
primaryStage.setScene(scene);
primaryStage.show();
btn.setOnAction((ActionEvent e) -> {
if (txtname3.getText().equals("") || txtname4.getText().equals("") || txtname5.getText().equals(""))
txtname6.setText("");
else {
try {
txtname6.setText(String.valueOf(Double.valueOf(cq)));
}
catch (Exception ex) {
txtname6.setText("error");
}
}
});
}
}
以下是在应用程序启动方法中引发的异常：
java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:473)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:372)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:941)
Caused by: java.lang.RuntimeException: Exception in Application start method
at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:973)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:198)
at java.base/java.lang.Thread.run(Thread.java:844)
Caused by: java.lang.NumberFormatException: For input string: ""
at java.base/java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.base/java.lang.Integer.parseInt(Integer.java:662)
at java.base/java.lang.Integer.valueOf(Integer.java:983)
at OlivePress.Main.start(Main.java:80)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:919)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$11(PlatformImpl.java:449)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$9(PlatformImpl.java:418)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:417)
at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:175)
... 1 more
Exception running application OlivePress.Main
Process finished with exit code 1
答案 0 :(得分：0)
检查txtname3输入值。您正在传递空字符串“”（来自txtname3.getText（）），由于没有为方法参数传递有效的整数，因此它会给NumberFormatException加薪。
Num=Integer.valueOf(txtname3.getText());
希望这会有所帮助！