本文介绍了使用JavaFX set和get方法时的InvocationTargetException的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
//Max Maier, Milan Radovanovic
package application;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
public class Control {
private static int anz = 1;
int generierteZahl = (int) Math.ceil(Math.random()*100);
Label anzversuche;
Label zahlenbereich;
Button ratenb;
TextField eingabe;
@FXML void raten(){
if (generierteZahl == Integer.parseInt(eingabe.getText())){
anzversuche.setText(anz + ". Versuche");
ratenb.setDisable(true);
zahlenbereich.setText("Richtig geraten!!!");
}
else if (generierteZahl > Integer.parseInt(eingabe.getText())){
anz++;
anzversuche.setText(anz + ". Versuche");
zahlenbereich.setText(Integer.parseInt(eingabe.getText()) + " ist zu klein");
}
else{
anzversuche.setText(anz + ". Versuche");
zahlenbereich.setText(Integer.parseInt(eingabe.getText()) + " ist zu groß");
}
anz++;
}
@FXML void neuerVersuch(){
anz = 1;
generierteZahl = (int) Math.ceil(Math.random()*100);
zahlenbereich.setText("Noch keine Zahl eingegeben");
anzversuche.setText(anz + ". Versuche");
ratenb.setDisable(false);
eingabe.setText("");
}
}
如果有例外：
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(Unknown Source)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(Unknown Source)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at javafx.event.Event.fireEvent(Unknown Source)
at javafx.scene.Node.fireEvent(Unknown Source)
at javafx.scene.control.Button.fire(Unknown Source)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(Unknown Source)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(Unknown Source)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(Unknown Source)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(Unknown Source)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at javafx.event.Event.fireEvent(Unknown Source)
at javafx.scene.Scene$MouseHandler.process(Unknown Source)
at javafx.scene.Scene$MouseHandler.access$1500(Unknown Source)
at javafx.scene.Scene.impl_processMouseEvent(Unknown Source)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(Unknown Source)
at com.sun.glass.ui.View.handleMouseEvent(Unknown Source)
at com.sun.glass.ui.View.notifyMouse(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$141(Unknown Source)
at com.sun.glass.ui.win.WinApplication$$Lambda$37/1109371569.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: 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 sun.reflect.misc.Trampoline.invoke(Unknown Source)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.reflect.misc.MethodUtil.invoke(Unknown Source)
... 48 more
Caused by: java.lang.NullPointerException
at application.Control.neuerVersuch(Control.java:34)
... 57 more
这是一个小数字猜谜游戏，其中创建一个随机数，然后与文本字段eingabe中的字符串进行比较。我明白为什么有时抛出NumberFormatException，但是调用异常是全新的，我真的很感激一些帮助。
It is a small number-guessing game where a random number is created and then compared with the String in the textfield "eingabe". I get why sometimes the NumberFormatException is thrown, but the invoke exception is completely new to and i really would appreciate some help.
推荐答案
最后的例外说：
Caused by: java.lang.NullPointerException
at application.Control.neuerVersuch(Control.java:34)
虽然我不知道它是什么行，但错误来了当 neuerVersuch 被调用时，它会找到一个未初始化的字段，可能是 zahlenbereich 。
Though I can't tell what line is it, the error comes when neuerVersuch is called, and it finds an uninitialized field, probably zahlenbereich.
原因是这个字段（可能是其他字段）没有实例化，因为它没有用 @FXML 。如果thouse是你的FXML文件中的控件，并且他们有一个 fx：id ，你应该注释它们：
The reason for this is this field (and maybe the others) is not instatiated since it is not annotated with @FXML. If thouse are controls in your FXML file, and they have an fx:id, you should annotate them:
@FXML Label anzversuche;
@FXML Label zahlenbereich;
@FXML Button ratenb;
@FXML TextField eingabe;
所以当加载控制器时，它们会被正确地即时显示。
so when the controller is loaded, they are properly instantited.
这篇关于使用JavaFX set和get方法时的InvocationTargetException的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！