CODEWITHSUNDEEP
spring-bootspring-integrationspring-rest
Imvejuru
Imvejuru

Reputation: 3

Download file by specific file name using FtpOutboundGateway

I'm implementing a service using Spring boot to download a single pattern-based file from an ftp server. The file name in the pattern changes based on the client's request parameters. And the file shouldn't be saved locally.

I'm new to this and I couldn't find a good explanation on how to achieve this using FtpOutboundGateway and Java config. Please help.

Here's some sample to show where I was taking this:

FtpOutboundGateway bean:

@Bean
@ServiceActivator(inputChannel = "requestChannel")
public FtpOutboundGateway ftpFileGateway() {
    FtpOutboundGateway ftpOutboundGateway =
                      new FtpOutboundGateway(ftpSessionFactory(), "get", "'Ready_Downloads/'");
    ftpOutboundGateway.setOptions("-P -stream");
    ftpOutboundGateway.setOutputChannelName("downloadChannel");
    return ftpOutboundGateway;
}

Use of autowired OutboundGateway ftpFileGateway bean in service endpoint:

@RequestMapping(value="/getFile", method = RequestMethod.POST, produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)
public @ResponseBody byte[] downloadFile(@RequestPart Map<String, String> fileDetails) throws Exception
{
    String filename = fileDetails.get("filename");

        FtpSimplePatternFileListFilter filter = new FtpSimplePatternFileListFilter( "*"+filename+"*");
        ftpFileGateway.setFilter(filter);

        //then what?...
}

I'm assuming I might need to use the input and output message channels, just not sure on how to proceed.

Upvotes: 0

Views: 1045

Answers (1)

Gary Russell
Gary Russell

Reputation: 174514

You shouldn't mutate the gateway for each request; it's not thread-safe.

You don't need a filter at all; simply send the fileName as the payload of the message sent to the get gateway and set the gateway expression to...

new FtpOutboundGateway(ftpSessionFactory(), "get", 
    "'Ready_Downloads/' + payload"

EDIT

@SpringBootApplication
public class So49516152Application {

    public static void main(String[] args) {
        SpringApplication.run(So49516152Application.class, args);
    }

    @Bean
    public ApplicationRunner runner (Gate gate) {
        return args -> {
            InputStream is = gate.get("bar.txt");
            File file = new File("/tmp/bar.txt");
            FileOutputStream os = new FileOutputStream(file);
            FileCopyUtils.copy(is, os);
            System.out.println("Copied: " + file.getAbsolutePath());
        };
    }

    @ServiceActivator(inputChannel = "ftpGet")
    @Bean
    public FtpOutboundGateway getGW() {
        FtpOutboundGateway gateway = new FtpOutboundGateway(sf(), "get", "'foo/' + payload");
        gateway.setOption(Option.STREAM);
        return gateway;
    }

    @Bean
    public DefaultFtpSessionFactory sf() {
        DefaultFtpSessionFactory sf = new DefaultFtpSessionFactory();
        sf.setHost("...");
        sf.setUsername("...");
        sf.setPassword("...");
        return sf;
    }

    @MessagingGateway(defaultRequestChannel = "ftpGet")
    public interface Gate {

        InputStream get(String fileName);

    }

}

Upvotes: 1

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