Class MyClassLoader:
public class MyClassLoader extends ClassLoader { public Class loadClassFromFile(File file) throws IOException { byte[] b = loadClassData(file); return defineClass(null, b, 0, b.length); } private byte[] loadClassData(File file) throws IOException { FileInputStream in = new FileInputStream(file); byte[] b = new byte[in.available()]; in.read(b); in.close(); return b; } } Call through this method:
@FXML public void handleLoadAndTabulate() throws IllegalAccessException, InstantiationException, ClassNotFoundException, InvocationTargetException, NoSuchMethodException, IOException { MyClassLoader myClassLoader = new MyClassLoader(); File file = fileChooser.showOpenDialog(main.getPrimaryStage()); System.out.println(1); Object o = myClassLoader.loadClassFromFile(file).newInstance(); if(o instanceof Function) System.out.println(true); System.out.println(1); System.out.println(1); } Throws an error:
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException 1 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.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58) 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.control.MenuItem.fire(MenuItem.java:462) at com.sun.javafx.scene.control.skin.ContextMenuContent$MenuItemContainer.doSelect(ContextMenuContent.java:1405) at com.sun.javafx.scene.control.skin.ContextMenuContent$MenuItemContainer.lambda$createChildren$343(ContextMenuContent.java:1358) at com.sun.javafx.event.CompositeEventHandler$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.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$MouseEventNotification.run(GlassViewEventHandler.java:352) at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:275) at java.security.AccessController.doPrivileged(Native Method) at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:388) at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389) at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:387) at com.sun.glass.ui.View.handleMouseEvent(View.java:555) at com.sun.glass.ui.View.notifyMouse(View.java:937) at com.sun.glass.ui.win.WinApplication._runLoop(Native Method) at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191) at java.lang.Thread.run(Thread.java:745) Caused by: java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:497) at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71) at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:497) at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275) at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1771) ... 43 more Caused by: java.lang.NoClassDefFoundError: functions/basic/TrigonometricFunction at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:760) at java.lang.ClassLoader.defineClass(ClassLoader.java:642) at functions.fx.MyClassLoader.loadClassFromFile(MyClassLoader.java:18) at functions.fx.ControllerTable.handleLoadAndTabulate(ControllerTable.java:139) ... 53 more Caused by: java.lang.ClassNotFoundException: Exception while looking for class functions.basic.TrigonometricFunction: java.io.IOException: Couldn't find: functions.basic.TrigonometricFunction.class at com.sun.org.apache.bcel.internal.util.SyntheticRepository.loadClass(SyntheticRepository.java:154) at com.sun.org.apache.bcel.internal.util.ClassLoader.loadClass(ClassLoader.java:154) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ... 58 more I always open the file with the .class extension. What is the problem?
Sample Log.class File
// // Source code recreated from a .class file by IntelliJ IDEA // (powered by Fernflower decompiler) // package functions.basic; import functions.Function; public class Log implements Function { private double base; public Log(double base) { this.base = base; } public Log() { this.base = 2.718281828459045D; } public double getLeftDomainBorder() { return 0.0D; } public double getRightDomainBorder() { return 1.0D / 0.0; } public double getFunctionValue(double x) { return Math.log(x) / Math.log(this.base); } } 