Textfield.getstringが私のJava FXプログラムで動作していないが、mannuly文字列を挿入する

Question

に動作します私は、MySQLデータベース

にそれに接続するためのユーザー名とパスワードを取ることができたJavaFXでのログインフォーラムを作成しようとしていたのはなぜコントローラクラスのコードがある

@FXML 
public Connection Button_Action() throws Exception { 

    String driver = "com.mysql.jdbc.Driver"; 
    String url = "jdbc:mysql://127.0.0.1:3306/?user=root&useSSL=false"; 
    Class.forName(driver); 

    Connection conn = DriverManager.getConnection(url, dbms_username.getText(),dbms_password.getText()); 
    System.out.println("Conneted"); 
    return conn; 

} dbms_usernameとdbms_passwordはFXMLファイル内creaetedれるテキストフィールドのIDである

このコードが動作し、エラー

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:49) 
    at javafx.event.Event.fireEvent(Event.java:198) 
    at javafx.scene.Node.fireEvent(Node.java:8413) 
    at javafx.scene.control.Button.fire(Button.java:185) 
    at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182) 
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96) 
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89) 
    at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218) 
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80) 
    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$MouseHandler.process(Scene.java:3757) 
    at javafx.scene.Scene$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$MouseEventNotification.run(GlassViewEventHandler.java:380) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:294) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:416) 
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:415) 
    at com.sun.glass.ui.View.handleMouseEvent(View.java:555) 
    at com.sun.glass.ui.View.notifyMouse(View.java:937) 
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method) 
    at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191) 
    at java.lang.Thread.run(Thread.java:745) 
Caused by: java.lang.reflect.InvocationTargetException 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
    at java.lang.reflect.Method.invoke(Method.java:498) 
    at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71) 
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
    at java.lang.reflect.Method.invoke(Method.java:498) 
    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275) 
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1771) 
    ... 48 more 
Caused by: java.lang.NullPointerException 
    at sample.Window1controller.Button_Action(Window1controller.java:72) 
    ... 58 more 

を与えることが、私が使用している場合、この

@FXML 
    public Connection Button_Action() throws Exception { 




String driver = "com.mysql.jdbc.Driver"; 
String url = "jdbc:mysql://127.0.0.1:3306/?user=root&useSSL=false"; 
Class.forName(driver); 
Connection conn = DriverManager.getConnection(url, "root","20080"); 
System.out.println("Conneted"); 
     return conn; 





} 

すべてが正常に動作していない

ここに加えて

は、私が作成したFXMLファイルの一部です。詳細についてはフォーラム

<TextField id="dbms_username" promptText="Username"> 
       <VBox.margin> 
        <Insets left="20.0" /> 
       </VBox.margin> 
      </TextField> 
      <Label layoutX="10.0" layoutY="10.0" text="Password"> 
       <VBox.margin> 
        <Insets left="20.0" top="20.0" /> 
       </VBox.margin> 
      </Label> 
      <TextField id="dbms_password" layoutX="10.0" layoutY="10.0" promptText="Password"> 
       <VBox.margin> 
        <Insets left="20.0" /> 
       </VBox.margin> 
      </TextField> 
      <HBox prefHeight="79.0" prefWidth="211.0"> 
       <children> 
        <Region prefHeight="79.0" prefWidth="155.0" /> 
        <Button id="dbms_button" mnemonicParsing="false" onAction="#Button_Action" prefHeight="25.0" prefWidth="55.0" text="Login"> 
        <HBox.margin> 
         <Insets top="5.0" /> 
        </HBox.margin> 
        </Button> 

私の質問はどのように私はクレアデータベースにログインするためのMySQLユーザ名とパスワードのログイン

Answer 1

fxmlファイルでは、-fx-idではなくidを使用してテキストフィールドを参照しました。 fx idを使用して、コントローラクラスのテキストフィールドを参照しようとします。