java.io.NotSerializableException with JFileChooser and new file - nullpointerexception

Question

I've recently run into a problem that wasn't occurring previously in my program. I'm getting a NotSerializableException when using JFileChooser and writeObject, but it only occurs if the file is new. Running the exact same code on an existing file (even if it's the one that popped the original error) works just fine. Removing JFileChooser from the code and providing a generic filename and location (the commented out section below) has no issues writing the object. I do not have a stored variable of JFileChooser, I'm simply using a local instance to get the filename/directory which is why I can't figure out what the problem is. The two objects I am trying to write (to include any included classes/variables) don't use JFileChooser either. I have tried placing my JFileChooser into a separate method from that containing my writeObject command, but with no change.
-There is a NullPointerException further down in the stacktrace that may be causing the overall issue, but I have not been able to track down what is causing that error. Thanks in advance!
java.io.NotSerializableException: sun.swing.plaf.synth.SynthFileChooserUIImpl
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1185)
at java.base/java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1553)
at java.base/java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1510)
at java.base/java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1433)
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1179)
at java.base/java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:349)
at java.desktop/javax.swing.event.EventListenerList.writeObject(EventListenerList.java:276)
at java.base/jdk.internal.reflect.GeneratedMethodAccessor19.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at java.base/java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1130)
at java.base/java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1497)
at java.base/java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1433)
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1179)
at java.base/java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1553)
at java.base/java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:442)
at java.desktop/javax.swing.JComponent.writeObject(JComponent.java:5578)
at java.base/jdk.internal.reflect.GeneratedMethodAccessor18.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at java.base/java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1130)
at java.base/java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1497)
at java.base/java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1433)
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1179)
at java.base/java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1553)
at java.base/java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1510)
at java.base/java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1433)
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1179)
at java.base/java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1553)
at java.base/java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:442)
at java.desktop/java.awt.Window.writeObject(Window.java:2958)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at java.base/java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1130)
at java.base/java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1497)
at java.base/java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1433)
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1179)
at java.base/java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:349)
at java.desktop/java.awt.Window.writeObject(Window.java:2975)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at java.base/java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1130)
at java.base/java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1497)
at java.base/java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1433)
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1179)
at java.base/java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:349)
at java.desktop/java.awt.AWTEventMulticaster.save(AWTEventMulticaster.java:1033)
at java.desktop/java.awt.Window.writeObject(Window.java:2963)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at java.base/java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1130)
at java.base/java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1497)
at java.base/java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1433)
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1179)
at java.base/java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1553)
at java.base/java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1510)
at java.base/java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1433)
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1179)
at java.base/java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:349)
at java.base/java.util.ArrayList.writeObject(ArrayList.java:863)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at java.base/java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1130)
at java.base/java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1497)
at java.base/java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1433)
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1179)
at java.base/java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:349)
at schedule.master.ScheduleMaster.saveCompleteSchedule(ScheduleMaster.java:7511)
at schedule.master.ScheduleMaster$107.actionPerformed(ScheduleMaster.java:3760)
at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1967)
at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2308)
at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)
at java.desktop/javax.swing.AbstractButton.doClick(AbstractButton.java:369)
at java.desktop/javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1020)
at java.desktop/javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:1064)
at java.desktop/java.awt.Component.processMouseEvent(Component.java:6636)
at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3342)
at java.desktop/java.awt.Component.processEvent(Component.java:6401)
at java.desktop/java.awt.Container.processEvent(Container.java:2263)
at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5012)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4844)
at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4918)
at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4547)
at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4488)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2307)
at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2762)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4844)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at java.desktop/javax.swing.plaf.synth.SynthLookAndFeel$Handler.repaintIfBackgroundsDiffer(SynthLookAndFeel.java:969)
at java.desktop/javax.swing.plaf.synth.SynthLookAndFeel$Handler.propertyChange(SynthLookAndFeel.java:931)
at java.desktop/java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:341)
at java.desktop/java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:333)
at java.desktop/java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:266)
at java.desktop/java.awt.KeyboardFocusManager.firePropertyChange(KeyboardFocusManager.java:1487)
at java.desktop/java.awt.KeyboardFocusManager.setGlobalFocusOwner(KeyboardFocusManager.java:580)
at java.desktop/java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:694)
at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:4893)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4844)
at java.desktop/sun.awt.SunToolkit$1.run(SunToolkit.java:441)
at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:770)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:740)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:117)
at java.desktop/java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:190)
at java.desktop/java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:235)
at java.desktop/java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:233)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:312)
at java.desktop/java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:233)
at java.desktop/java.awt.Dialog.show(Dialog.java:1070)
at java.desktop/javax.swing.JOptionPane.showOptionDialog(JOptionPane.java:874)
at java.desktop/javax.swing.JOptionPane.showMessageDialog(JOptionPane.java:670)
at java.desktop/javax.swing.JOptionPane.showMessageDialog(JOptionPane.java:641)
at schedule.master.ScheduleMaster.logError(ScheduleMaster.java:255)
at schedule.master.ScheduleMaster.saveCompleteSchedule(ScheduleMaster.java:7522)
at schedule.master.ScheduleMaster$107.actionPerformed(ScheduleMaster.java:3760)
at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1967)
at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2308)
at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)
at java.desktop/javax.swing.AbstractButton.doClick(AbstractButton.java:369)
at java.desktop/javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1020)
at java.desktop/javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:1064)
at java.desktop/java.awt.Component.processMouseEvent(Component.java:6636)
at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3342)
at java.desktop/java.awt.Component.processEvent(Component.java:6401)
at java.desktop/java.awt.Container.processEvent(Container.java:2263)
at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5012)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4844)
at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4918)
at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4547)
at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4488)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2307)
at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2762)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4844)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
public File getSaveFile() {
FileNameExtensionFilter fileFilter = new FileNameExtensionFilter("FAST Schedules", "skd", "SKD");
JFileChooser fileChooser = new JFileChooser();
if (saveFileName != null) {
fileChooser.setSelectedFile(new File(saveFileDirectory + "/" + saveFileName));
} else {
fileChooser.setSelectedFile(new File("Master Schedule.skd"));
}
fileChooser.setDialogTitle("Save location...");
fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
fileChooser.setAcceptAllFileFilterUsed(false);
fileChooser.setFileFilter(fileFilter);
File tempDirectory = null;
String tempFileName = "";
boolean saveOK = false;
if (fileChooser.showSaveDialog(null) == JFileChooser.APPROVE_OPTION) {
tempDirectory = fileChooser.getCurrentDirectory();
if (fileChooser.getSelectedFile().getName().toLowerCase().contains(".skd")) {
tempFileName = fileChooser.getSelectedFile().getName();
} else {
tempFileName = fileChooser.getSelectedFile().getName() + ".skd";
}
File checkFilename = new File(tempDirectory + "/" + tempFileName);
if (checkFilename.exists() == true) {
switch (JOptionPane.showConfirmDialog(null, "The file exists, overwrite?", "Existing file", JOptionPane.YES_NO_OPTION, JOptionPane.WARNING_MESSAGE)) {
case JOptionPane.YES_OPTION:
saveOK = true;
break;
}
} else {
saveOK = true;
}
//add in code to save user preferences to account for utilization rates
if (saveOK == true) {
return checkFilename;
}
}
return null;
}
public boolean saveCompleteSchedule() {
clearAll();
File file = getSaveFile();
if (file != null) {
FileOutputStream output;
ObjectOutputStream saveFile;
try {
output = new FileOutputStream(file);
saveFile = new ObjectOutputStream(output);
saveFile.writeObject(completeSquadronList);
saveFile.writeObject(dailyFlights);
saveFile.close();
output.close();
saveFileName = file.getName();
saveFileDirectory = file.getPath();
save = false;
return true;
} catch (IOException e) {
logError(e);
}
}
return false;
/*
File checkFilename = new File("temp.skd");
try {
FileOutputStream output = new FileOutputStream(checkFilename);
ObjectOutputStream saveFile = new ObjectOutputStream(output);
saveFile.writeObject(completeSquadronList);
saveFile.writeObject(dailyFlights);
saveFile.close();
output.close();
save = false;
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return true;
*/
}