SwingWorkerクラスのimportData(..)メソッドでを使用しようとしていますTransferHandler（ドラッグアンドドロップをサポートするため）。ドラッグしたファイルのインポートの進行状況を表示したいと思います。ただし、動作しません。何が問題なのか、何が原因なのかわかりません。
private class FileImportTransferHandler extends TransferHandler {
@Override
public boolean importData(JComponent comp, final Transferable t) {
SwingWorker<Void, String> worker = new SwingWorker<Void, String>() {
@Override
protected Void doInBackground() throws Exception {
//When commenting this code it and everything else it doesn't
DataFlavor[] flavors = t.getTransferDataFlavors(); //<---- throws exception
//..more code that doesn't run.
}
@Override
protected void done() {
super.done();
try {
get();
} catch (InterruptedException ex) {
Logger.getLogger(ImportBeanController.class.getName()).log(Level.SEVERE, null, ex);
} catch (ExecutionException ex) {
Logger.getLogger(ImportBeanController.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
//Starting worker etc here.
}
}
例外：
java.util.concurrent.ExecutionException：java.util.concurrent.FutureTask.get（FutureTask.java:83）のjava.util.concurrent.FutureTask $ Sync.innerGet（FutureTask.java:222）のjava.lang.NullPointerException javax.swing.SwingWorker.get（SwingWorker.java:582）at com.jatech.app.controllers $ ImportBeanController $ 1.done（ImportBeanController.java:158）at javax.swing.SwingWorker $ 5.run（SwingWorker.java:717） java.swing.SwingWorker $ DoSubmitAccumulativeRunnable.run（SwingWorker.java:814）at sun.swing.AccumulativeRunnable.run（AccumulativeRunnable.java:95）at javax.swing.SwingWorker $ DoSubmitAccumulativeRunnable.actionPerformed（SwingWorker.java:824）at javax.swing.Timer.fireActionPerformed（Timer.java:291）at javax.swing.Timer $ DoPostEvent.run（Timer.java:221）atjava.awt.event.InvocationEvent。ディスパッチ（InvocationEvent.java:209）at java.awt.EventQueue.dispatchEventImpl（EventQueue.java:641）at java.awt.EventQueue.access $ 000（EventQueue.java:84）at java.awt.EventQueue $ 1.run（EventQueue .java：602）at java.awt.EventQueue $ 1.run（EventQueue.java:600）at java.security.AccessController.doPrivileged（Native Method）at java.security.AccessControlContext $ 1.doIntersectionPrivilege（AccessControlContext.java:87）at java.awt.EventQueue.dispatchEvent（EventQueue.java:611）at java.awt.EventDispatchThread.pumpOneEventForFilters（EventDispatchThread.java:269）at java.awt.EventDispatchThread.pumpEventsForFilter（EventDispatchThread.java:184）at java.awt.EventDispatchThread .pumpEventsForHierarchy（EventDispatchThread.java:174）at java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java：169）at java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:161）at java.awt.EventDispatchThread.run（EventDispatchThread.java:122）原因：java.lang.NullPointerException at sun.awt.dnd.SunDropTargetContextPeer.getTransferDataFlavors （SunDropTargetContextPeer.java:176）at sun.awt.datatransfer.TransferableProxy.getTransferDataFlavors（TransferableProxy.java:48）at java.awt.dnd.DropTargetContext $ TransferableProxy.getTransferDataFlavors（DropTargetContext.java:327）getTransferDataFlavors（TransferableProxy.java:48）at java.awt.dnd.DropTargetContext $ TransferableProxy.getTransferDataFlavors（DropTargetContext.java:327）getTransferDataFlavors（TransferableProxy.java:48）at java.awt.dnd.DropTargetContext $ TransferableProxy.getTransferDataFlavors（DropTargetContext.java:327）