Spring集成：通过注释配置入站通道适配器

Question

如何通过注释而不是常规配置文件配置入站通道适配器？我可以为会话工厂定义bean，如下所示：

@Bean
public DefaultFtpSessionFactory ftpSessionFactory() {
        DefaultFtpSessionFactory ftpSessionFactory = new  
       DefaultFtpSessionFactory();
        ftpSessionFactory.setHost(host);
        ftpSessionFactory.setPort(port);
        ftpSessionFactory.setUsername(username);
        ftpSessionFactory.setPassword(password);
        return ftpSessionFactory;
    }

如何配置通过注释下给出的入站通道适配器？

<int-ftp:inbound-channel-adapter id="ftpInbound"
                                 channel="ftpChannel"
                                 session-factory="ftpSessionFactory"
                                 filename-pattern="*.xml"
                                 auto-create-local-directory="true"
                                 delete-remote-files="false"
                                 remote-directory="/"
                                 local-directory="ftp-inbound"
                                 local-filter="acceptOnceFilter">

    <int:poller fixed-delay="60000" max-messages-per-poll="-1">
        <int:transactional synchronization-factory="syncFactory" />
    </int:poller>

</int-ftp:inbound-channel-adapter>

@EnableIntegration
@Configuration
public class FtpConfiguration {
    @Value("${ftp.host}")
    private String host;
    @Value("${ftp.port}")
    private Integer port;
    @Value("${ftp.username}")
    private String username;
    @Value("${ftp.password}")
    private String password;
    @Value("${ftp.fixed.delay}")
    private Integer fixedDelay;
    @Value("${ftp.local.directory}")
    private String localDirectory;

    private final static Logger LOGGER =   LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());

@Bean
public SessionFactory<FTPFile> ftpSessionFactory() {
    DefaultFtpSessionFactory sessionFactory = new DefaultFtpSessionFactory();
    sessionFactory.setHost(host);
    sessionFactory.setPort(port);
    sessionFactory.setUsername(username);
    sessionFactory.setPassword(password);
    return new CachingSessionFactory<FTPFile>(sessionFactory);
}

@Bean
public FtpInboundFileSynchronizer ftpInboundFileSynchronizer() {
    FtpInboundFileSynchronizer fileSynchronizer = new FtpInboundFileSynchronizer(ftpSessionFactory());
    fileSynchronizer.setDeleteRemoteFiles(false);
    fileSynchronizer.setRemoteDirectory("/");
    fileSynchronizer.setFilter(new FtpSimplePatternFileListFilter("*.xml"));
    return fileSynchronizer;
}

@Bean
@InboundChannelAdapter(value = "ftpChannel",
        poller = @Poller(fixedDelay = "60000", maxMessagesPerPoll = "-1"))
public MessageSource<File> ftpMessageSource() {
    FtpInboundFileSynchronizingMessageSource source =
            new FtpInboundFileSynchronizingMessageSource(ftpInboundFileSynchronizer());
    source.setLocalDirectory(new File(localDirectory));
    source.setAutoCreateLocalDirectory(true);
    source.setLocalFilter(new AcceptOnceFileListFilter<File>());
    return source;
}

@Bean
public MessageChannel ftpChannel() {
    return new PollableChannel() {
        @Override
        public Message<?> receive() {
            return this.receive();
        }

        @Override
        public Message<?> receive(long l) {
            return null;
        }

        @Override
        public boolean send(Message<?> message) {
            return false;
        }

        @Override
        public boolean send(Message<?> message, long l) {
            return false;
        }
    };
}

我正在寻找的是在应用程序启动时连接所有bean，然后公开一些方法来开始轮询服务器，处理它们，然后从本地删除它们，类似于

public void startPollingTheServer() {
  getPollableChannel().receive();
}

其中getPollableChannel（）为我提供了用于轮询的bean。

Answer 1

您可以使用@InboundChannelAdapter。

@Bean
public FtpInboundFileSynchronizer ftpInboundFileSynchronizer() {
    FtpInboundFileSynchronizer fileSynchronizer = new FtpInboundFileSynchronizer(ftpSessionFactory());
    fileSynchronizer.setDeleteRemoteFiles(false);
    fileSynchronizer.setRemoteDirectory("/");
    fileSynchronizer.setFilter(new FtpSimplePatternFileListFilter("*.xml"));
    return fileSynchronizer;
}

@Bean
@InboundChannelAdapter(channel = "ftpChannel")
public MessageSource<File> ftpMessageSource() {
    FtpInboundFileSynchronizingMessageSource source =
            new FtpInboundFileSynchronizingMessageSource(ftpInboundFileSynchronizer());
    source.setLocalDirectory(new File("ftp-inbound"));
    source.setAutoCreateLocalDirectory(true);
    source.setLocalFilter(new AcceptOnceFileListFilter<File>());
    return source;
}

另外，请参阅参考手册。

另外，请注意Java DSL for Spring Integration的情况，其中类似的内容可能如下：

@Bean
public IntegrationFlow ftpInboundFlow() {
    return IntegrationFlows
            .from(s -> s.ftp(this.ftpSessionFactory)
                            .preserveTimestamp(true)
                            .remoteDirectory("ftpSource")
                            .regexFilter(".*\\.txt$")
                            .localFilename(f -> f.toUpperCase() + ".a")
                            .localDirectory(this.ftpServer.getTargetLocalDirectory()),
                    e -> e.id("ftpInboundAdapter").autoStartup(false))
            .channel(MessageChannels.queue("ftpInboundResultChannel"))
            .get();
}