我正在尝试创建一个用于多屏幕分辨率(也是高分辨率)的JavaFX应用程序。
-- exec-maven-plugin:1.2.1:exec (default-cli) @ SecureChat ---
dec 04, 2014 10:13:50 AM securechat.helpers.CustomStage initialize
SEVERE: null
javafx.fxml.LoadException: Cannot bind to static property.
file:/D:/private_java/SecureChat/target/SecureChat-1.0-SNAPSHOT.jar!/fxml/main.fxml:24
at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2591)
at javafx.fxml.FXMLLoader.access$100(FXMLLoader.java:104)
at javafx.fxml.FXMLLoader$Element.processPropertyAttribute(FXMLLoader.java:291)
at javafx.fxml.FXMLLoader$ValueElement.processEndElement(FXMLLoader.java:771)
at javafx.fxml.FXMLLoader.processEndElement(FXMLLoader.java:2817)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2526)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2435)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2403)
at securechat.helpers.CustomStage.initialize(CustomStage.java:111)
at securechat.helpers.CustomStage.<init>(CustomStage.java:104)
at securechat.MainApp.start(MainApp.java:40)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$153(LauncherImpl.java:821)
at com.sun.javafx.application.LauncherImpl$$Lambda$51/967161415.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$166(PlatformImpl.java:323)
at com.sun.javafx.application.PlatformImpl$$Lambda$45/584634336.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$null$164(PlatformImpl.java:292)
at com.sun.javafx.application.PlatformImpl$$Lambda$47/1040960283.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$165(PlatformImpl.java:291)
at com.sun.javafx.application.PlatformImpl$$Lambda$46/501263526.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$141(WinApplication.java:102)
at com.sun.glass.ui.win.WinApplication$$Lambda$37/96639997.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)
Exception in Application start method
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:363)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:303)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:875)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$147(LauncherImpl.java:157)
at com.sun.javafx.application.LauncherImpl$$Lambda$48/815033865.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException: Root cannot be null
at javafx.scene.Scene.<init>(Scene.java:313)
at javafx.scene.Scene.<init>(Scene.java:181)
at securechat.helpers.CustomStage.initialize(CustomStage.java:120)
at securechat.helpers.CustomStage.<init>(CustomStage.java:104)
at securechat.MainApp.start(MainApp.java:40)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$153(LauncherImpl.java:821)
at com.sun.javafx.application.LauncherImpl$$Lambda$51/967161415.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$166(PlatformImpl.java:323)
at com.sun.javafx.application.PlatformImpl$$Lambda$45/584634336.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$null$164(PlatformImpl.java:292)
at com.sun.javafx.application.PlatformImpl$$Lambda$47/1040960283.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$165(PlatformImpl.java:291)
at com.sun.javafx.application.PlatformImpl$$Lambda$46/501263526.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$141(WinApplication.java:102)
at com.sun.glass.ui.win.WinApplication$$Lambda$37/96639997.run(Unknown Source)
... 1 more
Exception running application securechat.MainApp
------------------------------------------------------------------------
BUILD FAILURE
------------------------------------------------------------------------
Total time: 9.363s
Finished at: Thu Dec 04 10:13:51 CET 2014
Final Memory: 19M/265M
------------------------------------------------------------------------
Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2.1:exec (default-cli) on project SecureChat: Command execution failed. Process exited with an error: 1 (Exit value: 1) -> [Help 1]
To see the full stack trace of the errors, re-run Maven with the -e switch.
Re-run Maven using the -X switch to enable full debug logging.
For more information about the errors and possible solutions, please read the following articles:
[Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
我正在使用以下代码段。
main.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import securechat.helpers.Scaling?>
<AnchorPane xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="securechat.controllers.MainController">
<children>
<fx:define>
<Scaling fx:id="dpi"></Scaling>
</fx:define>
<AnchorPane fx:id="chatsAnchorPane" maxWidth="${dpi.value*200}" minWidth="${dpi.value*200}" prefWidth="${dpi.value*200}" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.topAnchor="0.0">
<children>
<Button fx:id="openNewChatWindowButton" onAction="#openNewChatDialog" text="%button.openNewChatDialog" prefHeight="${dpi.value*40}" maxHeight="${dpi.value*40}" minHeight="${dpi.value*40}" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
<ListView fx:id="chatsListView" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="40.0" />
</children>
</AnchorPane>
<AnchorPane fx:id="chatAnchorPane" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="${dpi.value*200}" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<children>
<ListView fx:id="chatMessagesListView" AnchorPane.bottomAnchor="40.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
<TextField fx:id="chatMessageTextField" onAction="#sendChatMessage" promptText="%textfield.chatMessagePrompt" maxHeight="${dpi.value*40}" minHeight="${dpi.value*40}" prefHeight="${dpi.value*40}" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" />
</children>
</AnchorPane>
</children>
</AnchorPane>
Scaling.java
package securechat.helpers;
import java.awt.GraphicsEnvironment;
/**
*
*/
public final class Scaling {
public double value;
public Scaling() {
value = getDefaultScaling();
}
private double getDefaultScaling() {
int width = GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds().width;
return width / 1920;
}
public double getValue() {
return value;
}
}
经过html" target="_blank">调试,我发现在FXMLLoader
类中有几个LinkedList
列表。一个if例如属性属性,如PrefHeight=“400.0”
,另一个用于静态属性属性,如AnchorPane.bottomanchor=“0.0”
。
如果使用常规值,如PrefHeight=“400.0”
或绑定表达式,如PrefWidth=“${DPI.value*200}”
,则这些情况将在此方法ProcessPropertyAttribute()
中处理。
对于绑定,有三个初步检查:
@SuppressWarnings("unchecked")
public void processPropertyAttribute(Attribute attribute) throws IOException {
String value = attribute.value;
if (isBindingExpression(value)) {
// Resolve the expression
Expression expression;
if (attribute.sourceType != null) {
throw constructLoadException("Cannot bind to static property.");
}
if (!isTyped()) {
throw constructLoadException("Cannot bind to untyped object.");
}
if (this.value instanceof Builder) {
throw constructLoadException("Cannot bind to builder property.");
}
// Evaluate the expression
...
} else {
processValue(attribute.sourceType, attribute.name, value);
}
虽然prefwidth=“${dpi.value*200}”
通过了这些检查,但相反,在AnchorPane.leftanchor=“${dpi.value*200}”
上,您将发现它具有一个源类型:
attribute.sourceType = (java.lang.Class) class javafx.scene.layout.AnchorPane
因此,按照设计,这将发生:
if (attribute.sourceType != null) {
throw constructLoadException("Cannot bind to static property.");
}
双向绑定也是不可能的:
if (isBidirectionalBindingExpression(value)) {
throw constructLoadException(new UnsupportedOperationException("This feature is not currently enabled."));
}
表示静态属性的属性的处理方式与静态属性元素类似,并使用类似的语法。除了更简洁之外,静态属性属性(如实例属性属性)支持位置、资源和变量解析运算符,唯一的限制是不可能创建与静态属性绑定的表达式。
你得另想办法...
编辑
基于所提供的FXML,我建议避免静态属性的方法是使用hbox
和vbox
,通过绑定使用所需的min/pref/max大小,包装控件。
类似这样的事情:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import securechat.helpers.Scaling?>
<AnchorPane xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="securechat.controllers.MainController">
<children>
<fx:define>
<Scaling fx:id="dpi"></Scaling>
</fx:define>
<HBox AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<children>
<VBox fx:id="chatsVBox" maxWidth="${dpi.value*200}" minWidth="${dpi.value*200}" prefWidth="${dpi.value*200}" HBox.hgrow="NEVER">
<children>
<Button fx:id="openNewChatWindowButton" onAction="#openNewChatDialog" text="%button.openNewChatDialog" maxHeight="${dpi.value*40}" minHeight="${dpi.value*40}" prefHeight="${dpi.value*40}" prefWidth="${dpi.value*200}" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" VBox.vgrow="NEVER" />
<ListView fx:id="chatsListView" VBox.vgrow="ALWAYS" />
</children>
</VBox>
<VBox fx:id="chatVBox" HBox.hgrow="ALWAYS">
<children>
<ListView fx:id="chatMessagesListView" VBox.vgrow="ALWAYS" />
<TextField fx:id="chatMessageTextField" onAction="#sendChatMessage" maxHeight="${dpi.value*40}" minHeight="${dpi.value*40}" prefHeight="${dpi.value*40}" promptText="%textfield.chatMessagePrompt" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" VBox.vgrow="NEVER" />
</children>
</VBox>
</children>
</HBox>
</children>
</AnchorPane>
问题内容: 我对动态绑定和静态绑定感到非常困惑。我已经读过,在编译时确定对象的类型称为静态绑定,而在运行时确定它的称为动态绑定。 下面的代码会发生什么: 静态绑定还是动态绑定? 这表明什么样的多态性? 问题答案: 您的示例是 动态绑定 ,因为在运行时确定类型是什么,并调用适当的方法。 现在假设您也具有以下两种方法: 即使您更改为 这将打印出来,因为对的调用使用 静态绑定 ,并且编译器仅知道其类型。
静态绑定还是动态绑定? 这显示了什么样的多态性?
我们知道静态绑定发生在私有、静态、最终和重载的方法上,而动态绑定发生在被覆盖的方法上。但是如果我的方法只是公共的,它既不是静态的,也不是覆盖和重载的怎么办? 有人能给我解释一下print()的绑定会怎样,因为它既没有重载也没有被覆盖。
起初我是一个初学者 我看过很多教程,读过很多例子,甚至试图从JLS来理解这个主题,但我仍然有一些困惑或误解。 让我给你看我看不懂的问题。
我们可以把一个方法赋值给类的函数本身,而不是赋给它的 "prototype"。这样的方法被称为 静态的(static)。 在一个类中,它们以 static 关键字开头,如下所示: class User { static staticMethod() { alert(this === User); } } User.staticMethod(); // true 这实际上跟直接将其
本文向大家介绍java动态绑定和静态绑定用法实例详解,包括了java动态绑定和静态绑定用法实例详解的使用技巧和注意事项,需要的朋友参考一下 本文实例讲述了java动态绑定和静态绑定用法。分享给大家供大家参考,具体如下: 背景 1.当子类和父类存在同一个方法,子类重写了父类的方法,程序在运行时调用的是父类的方法还是子类的重写方法呢(尤其是存在向上类型转换的情况)? 2.当一个类中存在方法名相同但参数