Lensfield2_build_steps

Creating a Lensfield2 build step is very straightforward. In order to be used as a step in a Lensfield2 build a class simply has to implement a run method. Various fields can be marked to take inputs, outputs or parameters using annotations.

Build steps can be either 1:1, 1:n or n:1 file conversions through. Inputs are either be Lensfield2 StreamIn or StreamOut objects, or MultiStreamIn or MultiStreamOut objects. StreamIn and StreamOut extend java.io.InputStream and java.io.OutputStream, respectively, and provide access to read from or write to a single file, forming the '1' side of build steps. The MultiStream objects give access to a number of Streams, and are used to create 'n' sided build steps.

Examples of build steps

 * A 1:1 parameterised build step

 * A 1:n parameterised build step

 * An n:1 parameterised build step

n:n conversions are not (currently) supported, however it is worth noting that '1:x' here does not strictly mean a single input. but rather a fixed number of inputs/outputs, while 'n' means an indeterminate number of streams.

 * E.g., a 3:2 build step

Lensfield2 will populate each of these streams automatically.