I am using the Java Jersey to implement a REST service. One thing my service should provide is a file download option. These files are quite big and are constructed from dat
depends on the type of underlying database connection/driver, if you have access to the JDBC layer (e.g. using Hibernate) it should be possible to stream data using the JDBC Streaming API, then take the Streams from the ResultSet and pass them into Jersey's Response Builder. I have not done this myself though..
check here:
JDBC's getBinaryStream()
An example