java - Spring 集成: downloading only new or updated files from FTP server?

Question

我正在使用 Spring Integration 编写 FTP 客户端，用于从远程 FTP 服务器获取文件。此服务必须下载很大的文件，因此多次下载同一文件并不是最佳选择。

这是我的配置:

@Bean
open fun ftpSessionFactory() = DefaultFtpSessionFactory().apply {
    setHost(env.getProperty(FTP_HOST))
    setPort(env.getProperty(FTP_PORT)!!.toInt())
    setUsername(env.getProperty(FTP_USER))
    setPassword(env.getProperty(FTP_PASSWORD))
}

@Bean
open fun ftpInboundFileSynchronizer() = FtpInboundFileSynchronizer(
    ftpSessionFactory()).apply {
    setDeleteRemoteFiles(false)
    setRemoteDirectory(env.getProperty(FTP_REMOTE_DIRECTORY))
    setFilter(FtpSimplePatternFileListFilter(env.getProperty(FTP_FILTER)))
}

@Bean
@InboundChannelAdapter(channel = "ftpChannel")
open fun ftpMessageSource() = FtpInboundFileSynchronizingMessageSource(
    ftpInboundFileSynchronizer()).apply {
    setLocalDirectory(File(env.getProperty(FTP_LOCAL_DIRECTORY)))
    setAutoCreateLocalDirectory(true)
    setLocalFilter(AcceptOnceFileListFilter<File>())
    maxFetchSize = 1
}

@Bean(name = [(PollerMetadata.DEFAULT_POLLER)])
open fun defaultPoller() = PollerMetadata().apply {
    maxMessagesPerPoll = 1
}

我是否下载与 FTP_FILTER 匹配的所有文件或刚刚更改的文件？

Answer 1

除了 FtpSimplePatternFileListFilter 之外，您还需要对远程部分使用 AcceptOnceFileListFilter:https://docs.spring.io/spring-integration/docs/5.0.3.RELEASE/reference/html/ftp.html#ftp-inbound :

You can also combine a pattern based filter with other filters, such as an AcceptOnceFileListFilter to avoid synchronizing files that have previously been fetched, by using a CompositeFileListFilter.