DeleteFileOnExitHook Class — netty Architecture

Source Code

codec-http/src/main/java/io/netty/handler/codec/http/multipart/DeleteFileOnExitHook.java lines 25–81

final class DeleteFileOnExitHook {
    private static final Set<String> FILES = ConcurrentHashMap.newKeySet();

    private DeleteFileOnExitHook() {
    }

    static {
        // DeleteOnExitHook must be the last shutdown hook to be invoked.
        // Application shutdown hooks may add the first file to the
        // delete on exit list and cause the DeleteOnExitHook to be
        // registered during shutdown in progress.
        Runtime.getRuntime().addShutdownHook(new Thread() {

            @Override
            public void run() {
                runHook();
            }
        });
    }

    /**
     * Remove from the pool to reduce space footprint.
     *
     * @param file tmp file path
     */
    public static void remove(String file) {
        FILES.remove(file);
    }

    /**
     * Add to the hook and clean up when the program exits.
     *
     * @param file tmp file path
     */
    public static void add(String file) {
        FILES.add(file);
    }

    /**
     * Check in the hook files.
     *
     * @param file target file
     * @return true or false
     */
    public static boolean checkFileExist(String file) {
        return FILES.contains(file);
    }

    /**
     * Clean up all the files.
     */
    static void runHook() {
        for (String filename : FILES) {
            new File(filename).delete();
        }
    }
}