Files
spring-functions-catalog/supplier/spring-ftp-supplier

= FTP Supplier

This module provides an FTP supplier that can be reused and composed in other applications.
The `Supplier` uses the `FtpInboundChannelAdapter` from Spring Integration.
`FtpSupplier` is implemented as a `java.util.function.Supplier`.
This supplier gives you a reactive stream of files from the provided directory as the supplier has a signature of `Supplier<Flux<Message<?>>>`.
Users have to subscribe to this `Flux` and receive the data.

== Beans for injection

The `FtpSupplierConfiguration` auto-configuration provides the following bean:

`ftpSupplier`

You need to inject this as `Supplier<Flux<Message<?>>>`.

You can use `ftpSupplier` as a qualifier when injecting.

Once injected, you can use the `get` method of the `Supplier` to invoke it and then subscribe to the returned `Flux`.

== Configuration Options

All configuration properties are prefixed with `ftp.supplier`.
There are also properties that need to be used with the prefix `file.consumer`.

For more information on the various options available, please see link:src/main/java/org/springframework/cloud/fn/supplier/ftp/FtpSupplierProperties.java[FtpSupplierProperties].
See `FileConsumerProperties` also.

A `ComponentCustomizer<FtpInboundChannelAdapterSpec>` bean can be added in the target project to provide any custom options for the `FtpInboundChannelAdapterSpec` configuration used by the `ftpSupplier`.

== Tests

See this link:src/test/java/org/springframework/cloud/fn/supplier/ftp/FtpSupplierTests.java[test suite] for the various ways, this supplier is used.

== Other usage

See this https://github.com/spring-cloud/stream-applications/blob/master/applications/source/ftp-source/README.adoc[README] where this supplier is used to create a Spring Cloud Stream application where it makes a File Source.