Many CICS programming commands pass data in a structure known as a “communications
area” (COMMAREA). An alternative, and more flexible,
method of passing data between programs, is to use a channel: channels are
described in Channels and containers.
The COMMAREA or channel, and any other parameters, are passed as arguments
to the appropriate methods.
Many of the methods are overloaded—that is, they have different versions
that take either a different number of arguments or arguments of a different
type. There may be one method that has no arguments, or the minimum mandatory
arguments, and another that has all of the arguments. For example, there are
the following different link() methods in the Program class:
- link()
- This version does a simple LINK without using a COMMAREA to pass data,
nor any other options.
- link(com.ibm.cics.server.CommAreaHolder)
- This version does a simple LINK, using a COMMAREA to pass data but without
any other options.
- link(com.ibm.cics.server.CommAreaHolder, int)
- This version does a distributed LINK, using a COMMAREA to pass data and
a DATALENGTH value to specify the length of the data within the COMMAREA.
- link(com.ibm.record.IByteBuffer)
- This version does a LINK using an object that implements the IByteBuffer interface
of the Java Record Framework supplied with VisualAge for Java.
- link(com.ibm.cics.server.Channel)
- This version does a LINK using a channel to pass data in one or more containers.