A mapping lookup enables a function in application system to be called while a mapping program is being executed. This therefore requires the Integration Server and the application system to communicate with each other. This is achieved by using an adapter, which can be accessed by using the mapping program. In this way, the channel for communication is visible in the Integration Directory.
At runtime, the lookup API encapsulates the adapter call by using the central or non-central Adapter Engine:
The call is synchronous. This means that the adapter called returns the result of the call immediately (not represented in the graphic).
The lookup API is part of the mapping API and can therefore be used in the following types of mapping programs:
● Java mapping programs
● XSLT mapping programs with Java enhancements
● User-defined functions of message mappings
● There is a standard function in the mapping editor for calls using the JDBC adapter that enables you to read values from a database.
Regardless of the mapping program used, implementation using the lookup API in the mapping program requires the application system to be called by means of a communication channel in the Integration Directory. Besides the implementation in the mapping program, you must also perform the following steps:
● Instead of concealing the name of the communication channel by explicitly using it in the mapping program, developers use an import parameter of type Adapter to transfer the communication channel ID to the lookup API. In this way, the lookup using the mapping program parameter or the relevant operation mapping parameter is visible on the interface of the mapping program (see also: Parameterized Mapping Programs).
● To execute (and therefore test) the lookup, the following prerequisites must also be satisfied:
○ You must have configured the receiver channel for the lookup call in the Integration Directory. You must have assigned this channel to the operation mapping parameter in the interface determination.
○ The Integration Server runtime components must be installed.
If these requirements are not fulfilled, the mapping will terminate with an error.
Any necessary configuration work in the Integration Directory at the customer site is the task of consultants, but must be performed by developers for test purposes.