question: private FileChannel updateCache ( String filePath ) { FileChannel fileChannel = fileNameAndStreamCache . get ( filePath ) ; try { if ( null == fileChannel ) { FileInputStream stream = new FileInputStream ( filePath ) ; fileChannel = stream . getChannel ( ) ; fileNameAndStreamCache . put ( filePath , fileChannel ) ; } } catch ( IOException e ) { LOGGER . error ( e , e . getMessage ( ) ) ; } return fileChannel ; }
target:  This method will be used to check whether stream is already present in cache or not for filepath if not present then create it and then add to cache, other wise get from cache