You can look up data by using a reference link to link
the Java Integration stage to a Lookup stage.
About this task
You can select the lookup type as Normal or Sparse in the
stage editor. For a normal lookup, your Java code does not need any
implementation as the output reference link is treated same as output
stream link. However, sparse lookup internally changes the link topology
in such a way that the connector contains one input link, one output
link, and an optional reject link.When Sparse lookup is selected,
make sure that only one output reference link is connected to the
Java Integration stage.