我正在尝试使用某种类型User的ObservableList，如果存储在其中的某个项目的任何值发生了变化，它将通知任何listchangelistener。
虽然回调总是抛出异常：
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:498)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
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.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$1(LauncherImpl.java:182)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NoClassDefFoundError: groovy/lang/GroovyObject
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
at java.lang.ClassLoader.defineClass(ClassLoader.java:642)
at org.codehaus.groovy.runtime.ProxyGeneratorAdapter$InnerLoader.defineClass(ProxyGeneratorAdapter.java:926)
at org.codehaus.groovy.runtime.ProxyGeneratorAdapter.<init>(ProxyGeneratorAdapter.java:191)
at groovy.util.ProxyGenerator.createAdapter(ProxyGenerator.java:233)
at groovy.util.ProxyGenerator.instantiateDelegateWithBaseClass(ProxyGenerator.java:208)
at groovy.util.ProxyGenerator.instantiateDelegateWithBaseClass(ProxyGenerator.java:192)
at groovy.util.ProxyGenerator.instantiateDelegate(ProxyGenerator.java:184)
at groovy.util.ProxyGenerator.instantiateDelegate(ProxyGenerator.java:180)
at org.codehaus.groovy.runtime.DefaultGroovyMethods.asType(DefaultGroovyMethods.java:15768)
at org.codehaus.groovy.runtime.DefaultGroovyMethods.asType(DefaultGroovyMethods.java:10859)
at org.codehaus.groovy.runtime.dgm$53.doMethodInvoke(Unknown Source)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1225)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1034)
at org.codehaus.groovy.runtime.InvokerHelper.invokePojoMethod(InvokerHelper.java:935)
at org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.java:926)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodN(ScriptBytecodeAdapter.java:181)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.asType(ScriptBytecodeAdapter.java:604)
at sample.Main$1.call(Main.groovy:36)
at sample.Main$1.call(Main.groovy)
at com.sun.javafx.collections.ElementObserver.attachListener(ElementObserver.java:79)
at com.sun.javafx.collections.ObservableListWrapper.doAdd(ObservableListWrapper.java:100)
at javafx.collections.ModifiableObservableListBase.add(ModifiableObservableListBase.java:151)
at java.util.AbstractList.add(AbstractList.java:108)
at java.util.AbstractCollection.addAll(AbstractCollection.java:344)
at javafx.collections.ModifiableObservableListBase.addAll(ModifiableObservableListBase.java:99)
at javafx.collections.ObservableListBase.addAll(ObservableListBase.java:245)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite$PojoCachedMethodSite.invoke(PojoMetaMethodSite.java:192)
at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite.call(PojoMetaMethodSite.java:56)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:136)
at sample.Main.start(Main.groovy:39)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$8(LauncherImpl.java:863)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$7(PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$5(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$6(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
at com.sun.glass.ui.gtk.GtkApplication.lambda$null$5(GtkApplication.java:139)
... 1 more
Caused by: java.lang.ClassNotFoundException: groovy.lang.GroovyObject
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at groovy.lang.GroovyClassLoader.loadClass(GroovyClassLoader.java:702)
at groovy.lang.GroovyClassLoader.loadClass(GroovyClassLoader.java:812)
at groovy.lang.GroovyClassLoader.loadClass(GroovyClassLoader.java:800)
... 47 more
Exception running application sample.Main
我能够通过这个例子重现错误：
package sample
import javafx.application.Application
import javafx.beans.Observable
import javafx.collections.FXCollections
import javafx.collections.ObservableList
import javafx.scene.Scene
import javafx.scene.control.ComboBox
import javafx.stage.Screen
import javafx.stage.Stage
import javafx.util.Callback
class Main extends Application {
static void main(String[] args) {
launch(Main.class, args)
}
class User {
String name
User(String t){
name = t
}
}
@Override
void start(Stage primaryStage) {
ObservableList<User> usersTest =
FXCollections.observableArrayList(new Callback<User, Observable[]>() {
@Override
Observable[] call(User o) {
return [o] as Observable
}
})
usersTest.addAll( new User("John"), new User("Jane"))
ComboBox<User> cb = new ComboBox<>()
cb.setItems(usersTest)
cb.value = cb.items.first()
def bounds = Screen.primary.bounds
Scene scene = new Scene(cb, bounds.width, bounds.height)
primaryStage.setScene(scene)
primaryStage.show()
}
}
老实说，我有点没有选择，因为错误是无益的。