question: public static Collection < File > listFilesAndDirs ( File directory , IOFileFilter fileFilter , IOFileFilter dirFilter ) { validateListFilesParameters ( directory , fileFilter ) ; IOFileFilter effFileFilter = setUpEffectiveFileFilter ( fileFilter ) ; IOFileFilter effDirFilter = setUpEffectiveDirFilter ( dirFilter ) ; Collection < File > files = new java . util . LinkedList < File > ( ) ; if ( directory . isDirectory ( ) ) { files . add ( directory ) ; } innerListFiles ( files , directory , FileFilterUtils . or ( effFileFilter , effDirFilter ) , true ) ; return files ; }
target:  Finds files within a given directory (and optionally its subdirectories). All files found are filtered by an IOFileFilter. <p> The resulting collection includes the subdirectories themselves. <p>