Handle file contents and write out to a file

MessageProcessingIntegrationFlow.java

    @Bean
    public IntegrationFlow writeToFile(@Qualifier("fileWritingMessageHandler") MessageHandler fileWritingMessageHandler) {
        return IntegrationFlows.from(ApplicationConfiguration.INBOUND_CHANNEL)
                .transform(m -> new StringBuilder((String)m).reverse().toString())
                .handle(fileWritingMessageHandler)
                .log(LoggingHandler.Level.INFO)
                .get();
    }


    @Bean (name = FILE_WRITING_MESSAGE_HANDLER)
    public MessageHandler fileWritingMessageHandler(@Qualifier(OUTBOUND_FILENAME_GENERATOR) FileNameGenerator fileNameGenerator) {
        FileWritingMessageHandler handler = new FileWritingMessageHandler(inboundOutDirectory);
        handler.setAutoCreateDirectory(true);
        handler.setFileNameGenerator(fileNameGenerator);
        return handler;
    }

    @Bean(name = OUTBOUND_FILENAME_GENERATOR)
    public FileNameGenerator outboundFileName(@Value("${out.filename.dateFormat}") String dateFormat, @Value("${out.filename.suffix}") String filenameSuffix) {
        return message -> DateTimeFormatter.ofPattern(dateFormat).format(LocalDateTime.now()) + filenameSuffix;
    }