我已经阅读了有关该主题的多个主题，但是似乎都没有一个问题可以回答我的特定问题。在“设置”包中，我有一个SettingModel.java类，该类使用jaxb从default.xml文件加载默认设置。这完美无瑕。然后，在同一个程序包下的一个名为SettingsWidgets的子程序包中，我有一个SaveButton.java类，该类具有一个setOnMouseClick eventListener，触发了方法“ saveSettings”。该代码部分起作用：当前文件被覆盖（尽管带有空白）或在所需的包中创建了一个新的（至今为空）xml文件，但出现错误
javax.xml.bind.JAXBException: class settings.settingsWidgets.SaveButton nor any of its super class is known to this context.
我已经尝试过：按照堆栈O上几个线程中的建议以不同的方式创建JAXBContext（将包作为字符串传递并添加jaxb.index和ObjectFactory.java，传递完整的类路径而不是仅传递类，... ）无济于事，在我看来（读取错误）问题不是我如何将SettingsModel类传递给上下文...
@XmlSeealso解决方法也经常被提及，但是我并没有立即看到它的用途（这并不是说我试图封送一个子类或其他东西）
还尝试将
SaveButton.java重构出子包，使其与SettingsModel处于同一级别，但这并没有改变任何内容...我对如何以及为什么应该将
SaveButton包含在jaxbContext中以及尝试时遇到很多错误感到迷茫。我的代码：
// SettingsModel.java
@XmlRootElement(name = "robot")
@XmlAccessorType(XmlAccessType.FIELD)
public class SettingsModel implements Observable {
private boolean valid = true;
//registered views List
//annotate as Type Object.Class because JAXB cannot handle interfaces
@XmlElement(type = Object.class)
private ArrayList<InvalidationListener> listenersList;
//list all variable robot/vehicle specs
//filename is needed for saving to current or new file
@XmlElement(name = "filename")
private String fileName;
@XmlElement(name = "vehicle-width")
private double vehicleWidth;
@XmlElement(name = "work-width")
private double workWidth;
// other getters and setters without logic are removed
public void setValid(boolean valid) {
if (valid != this.valid) {
this.valid = valid;
fireInvalidationEvent();
}
}
public void setVehicleWidth(double vehicleWidth) {
this.vehicleWidth = vehicleWidth;
Field.getInstance().getRobot().setVehicleWidth(vehicleWidth);
fireInvalidationEvent();
}
public void setWorkWidth(double workWidth) {
this.workWidth = workWidth;
// Field.getInstance().getRobot().setVehicleWidth(vehicleWidth);
// fireInvalidationEvent();
}
//METHODS AND FUNCTIONS
@Override
public void addListener(InvalidationListener invalidationListener) {
listenersList.add(invalidationListener);
}
@Override
public void removeListener(InvalidationListener invalidationListener) {
listenersList.remove(invalidationListener);
}
public void fireInvalidationEvent() {
for (InvalidationListener listener : listenersList) {
listener.invalidated(this);
}
}
}
// SaveButton.java
public class SaveButton extends Button implements InvalidationListener {
private SettingsModel model;
public SaveButton(SettingsModel model) {
this.model = model;
model.addListener(this);
setText("SAVE SETTINGS");
setOnMouseClicked((ev)->{
try {
saveSettings();
} catch (JAXBException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
});
}
private void saveSettings() throws JAXBException, FileNotFoundException {
String filename = model.getFileName();
Object[] options = {"Save", "Save As"};
//choose Save or Save As
int choice = JOptionPane.showOptionDialog(null,"Overwrite current file or Save As New file?",
"Save Settings",
JOptionPane.WARNING_MESSAGE,
JOptionPane.YES_NO_OPTION,
null,
options,
options[0]
);
if(choice != JOptionPane.OK_OPTION){
filename = JOptionPane.showInputDialog("Enter new file name");
model.setFileName(filename);
}
System.out.println(model.getFileName());
//Marshal
JAXBContext jaxbContext = JAXBContext.newInstance(SettingsModel.class);
Marshaller jaxbMarshaller = jaxbContext.createMarshaller();
//if filename stays same, file is overwritten. Test only SAVE AS until code works to not lose default file
File file = new File("src/resources/properties/"+ filename + ".xml");
OutputStream os = new FileOutputStream(file);
jaxbMarshaller.marshal(model,os);
}
@Override
public void invalidated(Observable observable) {
System.out.println("button invalidated: "+ model.isValid());
setDisable(!model.isValid());
}
}
堆栈跟踪：
javax.xml.bind.MarshalException
- with linked exception:
[com.sun.istack.SAXException2: javax.xml.bind.JAXBException: class settings.settingsWidgets.SaveButton nor any of its super class is known to this context.
javax.xml.bind.JAXBException: class settings.settingsWidgets.SaveButton nor any of its super class is known to this context.]
at com.sun.xml.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:301)
at com.sun.xml.bind.v2.runtime.MarshallerImpl.marshal(MarshallerImpl.java:226)
at javax.xml.bind.helpers.AbstractMarshallerImpl.marshal(AbstractMarshallerImpl.java:80)
at settings.settingsWidgets.SaveButton.saveSettings(SaveButton.java:59)
at settings.settingsWidgets.SaveButton.lambda$new$0(SaveButton.java:27)
at javafx.base/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at javafx.base/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at javafx.base/com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at javafx.base/com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.base/javafx.event.Event.fireEvent(Event.java:198)
at javafx.graphics/javafx.scene.Scene$ClickGenerator.postProcess(Scene.java:3564)
at javafx.graphics/javafx.scene.Scene$ClickGenerator.access$8200(Scene.java:3492)
at javafx.graphics/javafx.scene.Scene$MouseHandler.process(Scene.java:3860)
at javafx.graphics/javafx.scene.Scene$MouseHandler.access$1200(Scene.java:3579)
at javafx.graphics/javafx.scene.Scene.processMouseEvent(Scene.java:1849)
at javafx.graphics/javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2588)
at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:397)
at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$2(GlassViewEventHandler.java:434)
at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:390)
at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:433)
at javafx.graphics/com.sun.glass.ui.View.handleMouseEvent(View.java:556)
at javafx.graphics/com.sun.glass.ui.View.notifyMouse(View.java:942)
at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:174)
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: com.sun.istack.SAXException2: javax.xml.bind.JAXBException: class settings.settingsWidgets.SaveButton nor any of its super class is known to this context.
javax.xml.bind.JAXBException: class settings.settingsWidgets.SaveButton nor any of its super class is known to this context.
at com.sun.xml.bind.v2.runtime.XMLSerializer.reportError(XMLSerializer.java:217)
at com.sun.xml.bind.v2.runtime.XMLSerializer.reportError(XMLSerializer.java:232)
at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:623)
at com.sun.xml.bind.v2.runtime.property.ArrayElementNodeProperty.serializeItem(ArrayElementNodeProperty.java:39)
at com.sun.xml.bind.v2.runtime.property.ArrayElementProperty.serializeListBody(ArrayElementProperty.java:142)
at com.sun.xml.bind.v2.runtime.property.ArrayERProperty.serializeBody(ArrayERProperty.java:129)
at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:329)
at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsSoleContent(XMLSerializer.java:563)
at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeRoot(ClassBeanInfoImpl.java:310)
at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsRoot(XMLSerializer.java:464)
at com.sun.xml.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:298)
... 34 more
Caused by: javax.xml.bind.JAXBException: class settings.settingsWidgets.SaveButton nor any of its super class is known to this context.
at com.sun.xml.bind.v2.runtime.JAXBContextImpl.getBeanInfo(JAXBContextImpl.java:563)
at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:618)
... 42 more
Process finished with exit code 0
任何见解将不胜感激。
最佳答案
您的SettingsModel具有标记为xmlelement的listenerList。您可以使用以下这一行将SaveButton添加到列表中：
model.addListener(this);
因此，在封送SettingsModel时，JAXB处理listenerList并尝试封送SaveButton，但它不知道如何执行。
在您的SaveButton类中添加一个@XmlRootElement批注就足够了。
此外，我看到每次单击按钮时都会创建一个JAXBContext。 JAXB规范说：
为了避免创建JAXBContext实例所涉及的开销，
鼓励JAXB应用程序重用JAXBContext实例。一个
必须是抽象类JAXBContext的实现
线程安全的，因此，应用程序中的多个线程可以共享
相同的JAXBContext实例。
您应该将JAXBContext移到一个静态字段，因为可以重用该实例。