What drives a Spring Batch application?

Batch can be driven by incoming File trigger, Database update, JMS (or some other) incoming message. 

In an application I worked on file trigger/JMS message used to initiate and drive the batch at different steps.

1. File Trigger: On the basis of input file and instruction thereof, action can be taken. Spring batch initiates and drives on the basis of the file data.

2. Database update: An incoming Database updates defines what the applications needs to do and how the batch will proceed.

3. Message: JMS message for example, read from a Queue can drive the batch.