About the Service Signature
Input and output parameters are the names and types of fields that the service requires as input and generates as output. Some systems refer to input and output parameters as “imports” and “exports.” These parameters are also collectively referred to as a signature. You declare a signature for all types of services: flow services, Java services, and services written in other supported programming languages.
For example, a service that takes two string values—an account number (AcctNum) and a dollar amount (OrderTotal)—as input and produces an authorization code (AuthCode) as output, has the following input and output parameters:
Input Parameters | | Output Parameters | | |
| Name | Data Type | | Name | Data Type | |
| AcctNum | String | | AuthCode | String | |
| OrderTotal | String | | | | |
| | | | | | |
Although you are not required to declare input and output parameters for a service (the Integration Server will execute a service regardless of whether it has a specification or not), there are good reasons to do so:
Declaring parameters makes the service’s input and outputs visible to
Designer. Without declared input and output parameters, you cannot:
Link data to and/or from the service using the Pipeline view.
Assign default input values to the service on the Pipeline view.
Validate the input and output values of the service at run time.
Log the input and output document fields of the service.
Run or debug the service in
Designer and enter initial input values.
Generate skeleton code for invoking the service from a client.
Declaring parameters makes the input and output requirements of your service known to other developers who may want to call your service from their programs.
For these reasons, it is strongly recommended that you make it a practice to declare a signature for every service that you create.
Designer supports several data types for use in services. Each data type supported by Designer corresponds to a Java data type and has an associated icon. When working in the editor, you can determine the data type for a field by looking at the icon next to the field name.