import java.beans.PropertyChangeListener;
import java.io.File;
import java.util.ArrayList;
+import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;
{
private static final long serialVersionUID = 1L;
- private Map<Object, Runnable> callbacks;
+ private Map<Object, Runnable> callbacks = new HashMap<>();
File selectedFile = null;