Service program call

The ServiceProgramCall class allows you to call an iSeries™ service program. ServiceProgramCall is a subclass of the ProgramCall class that you use to call iSeries programs. If you want to call an iSeries program, use the ProgramCall class.

The ServiceProgramCall class makes it possible for you to call an iSeries service program, pass data to an iSeries service program through input parameters, and access data the iSeries service program returns through output parameters. Using ServiceProgramCall causes the AS400 object to connect to the iSeries. See managing connections for information about managing connections.

The default behavior is for service programs to run in a separate server job, even when the Java™ program and the service program are on the same server. You can override the default behavior and have the service program run in the Java job using the inherited (from ProgramCall) setThreadSafe() method.

Using the ServiceProgramCall class

In order to use the ServiceProgramCall class, you must be sure to meet the following requirements:

• The service program must be on an iSeries
• You can pass no more than seven parameters to the service program
• The return value of the service program is void or numeric

Working with ProgramParameter objects

The ProgramParameter class works with the ServiceProgramCall class to pass parameter data to and from an iSeries service program. You pass input data to the iSeries service program with setInputData().

You request the amount of output data you want returned with setOutputDataLength(). You retrieve the output data after the service program is finished running with getOutputData(). In addition to the data itself, ServiceProgramCall needs to know how to pass parameter data to the service program. The setParameterType() method of ProgramParameter is used to supply this information. The type indicates if the parameter is pass by value or pass by reference. In either case, data is sent from the client to the server. Once the data is on the iSeries, the server uses the parameter type to correctly call the service program.

All parameters will be in the form of a byte array. Therefore, to convert between iSeries and Java formats, you use the data conversion and description classes.