File storage fails silently when setting a non-exitent file directory

[lenhard]

When I set the "Main file directory" (Preferences->External Programs->Main file directory) to a directory that does not exist, then file download fails silently.

I can trigger the dowload, choose to save the file and everything looks fine in the UI, but no entry appears in the file field. Looking at the console, the following stack trace appears:

java.io.FileNotFoundException: asd\hajjat10benefit.pdf (Das System kann den angegebenen Pfad nicht finden)
    at java.io.FileOutputStream.open(Native Method)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:206)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:156)
    at net.sf.jabref.logic.util.io.FileUtil.copyFile(FileUtil.java:122)
    at net.sf.jabref.external.DownloadExternalFile.download(DownloadExternalFile.java:220)
    at net.sf.jabref.external.FindFullTextAction.update(FindFullTextAction.java:72)
    at sun.reflect.GeneratedMethodAccessor28.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at spin.Invocation.evaluate(Invocation.java:175)
    at spin.over.SpinOverEvaluator.evaluate(SpinOverEvaluator.java:62)
    at spin.ProxyFactory.evaluteInvocation(ProxyFactory.java:85)
    at spin.JDKProxyFactory$SpinInvocationHandler.invoke(JDKProxyFactory.java:102)
    at com.sun.proxy.$Proxy0.update(Unknown Source)
    at net.sf.jabref.gui.BasePanel.runCommand(BasePanel.java:1232)
    at net.sf.jabref.gui.fieldeditors.FileListEditor$14.actionPerformed(FileListEditor.java:441)
    at net.sf.jabref.util.Util$1$1.run(Util.java:913)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:744)
    at java.awt.EventQueue.access$400(EventQueue.java:97)
    at java.awt.EventQueue$3.run(EventQueue.java:697)
    at java.awt.EventQueue$3.run(EventQueue.java:691)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:714)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:109)
    at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:184)
    at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:229)
    at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:227)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:227)
    at java.awt.Dialog.show(Dialog.java:1084)
    at java.awt.Component.show(Component.java:1656)
    at java.awt.Component.setVisible(Component.java:1608)
    at java.awt.Window.setVisible(Window.java:1014)
    at java.awt.Dialog.setVisible(Dialog.java:1005)
    at net.sf.jabref.util.Util$2.run(Util.java:925)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:744)
    at java.awt.EventQueue.access$400(EventQueue.java:97)
    at java.awt.EventQueue$3.run(EventQueue.java:697)
    at java.awt.EventQueue$3.run(EventQueue.java:691)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:714)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

Perhaps we should change the preference setting in the UI. Currently, it is a text field and the user can enter arbitrary text instead of using the FileChooser. If we set it to a Label instead, the user has to select the directory via the FileChooser. Additionally, there should be some error message to the user if the storage of the file fails.

[koppor]

I really like to entry the path manually. I typically copy and paste from the Windows explorer.

Similar issue for the directory per bibtex entry. There, I typically key in . to indicate that JabRef should search beginning from the directory of the bib file.

[lenhard]

Well, I also like to enter the path manually, so let's keep that.

So that means we should display a proper error message in the UI!

[matthiasgeiger]

Error message when saving the preferences?
Or: error message when storing of a downloaded file fails?
(Or in both cases to handle the issue that a formerly existing directory is deleted?)

[simonharrer]

👍 for both cases.

[koppor]

Related: JabRef#1949

[boceckts]

PR was merged and related issue is closed so I think this can be closed, too.

[lenhard]

@boceckts You are correct. To be on the safe side, I just tested it on master and the error message appears as desired.