This example demonstrates one technique for sending files to dynamic destinations.
See DynamicFtpChannelResolver. The resolve() method maps a customer to a channel, where the channel is defined in a separate application context for each customer. The application context property placeholders are configured using the Spring 3.1 Environment management by supplying a custom property source.
A real implementation would provide these properties based on the customer; this sample simply uses the customer as part of the host name. The application context is loaded from the file in src/main/resources/....
DynamicFtpChannelResolverTests is a simple JUnit test case that verifies the same channel is used for the same customer each time, and that a different channel is used for a different customer.
FtpOutboundChannelAdapterSample shows how messages sent with a different customer header are routed to a different ftp adapter. It simply verifies that the correct UnknownHostException is returned.
Notice in the config file, how an expression-based router is used to invoke the DynamicFtpChannelResolver to obtain a reference to the appropriate channel for the customer. Notice that the channel resolver is a simple POJO, invoked using SpEL...
<int:router input-channel="toDynRouter"
expression="@channelResolver.resolve(headers['customer'])"/>
This sample shows the technique for outbound adapters.