question: @ SuppressFBWarnings ( value = "NP_NULL_ON_SOME_PATH_FROM_RETURN_VALUE" , justification = "File.listFiles() will return null if the File instance is not a directory. " + "Null dereference is not a possibility here since we validate sourceDirectory is " + "directory via sourceDirectory.isDirectory()" ) public static void zipDirectory ( File sourceDirectory , OutputStream outputStream ) throws IOException { checkNotNull ( sourceDirectory ) ; checkNotNull ( outputStream ) ; checkArgument ( sourceDirectory . isDirectory ( ) , "%s is not a valid directory" , sourceDirectory . getAbsolutePath ( ) ) ; ZipOutputStream zos = new ZipOutputStream ( outputStream ) ; for ( File file : sourceDirectory . listFiles ( ) ) { zipDirectoryInternal ( file , "" , zos ) ; } zos . finish ( ) ; }
target:  Zips an entire directory specified by the path.