src/share/classes/java/io/FileFilter.java

@@ -33,10 +33,11 @@
  * File#listFiles(java.io.FileFilter) listFiles(FileFilter)}</code> method
  * of the <code>{@link java.io.File}</code> class.
  *
  * @since 1.2
  */
+@FunctionalInterface
 public interface FileFilter {
 
     /**
      * Tests whether or not the specified abstract pathname should be
      * included in a pathname list.

@@ -44,7 +45,6 @@
      * @param  pathname  The abstract pathname to be tested
      * @return  <code>true</code> if and only if <code>pathname</code>
      *          should be included
      */
     boolean accept(File pathname);
-
 }