Library structure

Each JCICS library component falls into one of four categories: Interfaces, Classes, Exceptions, or Errors.

Interfaces
Some interfaces are provided to define sets of constants. For example, the TerminalSendBits interface provides a set of constants that can be used to construct a java.util.BitSet.
Classes
The supplied classes provide most of the JCICS function. The API class is an abstract class that provides common initialization for every class that corresponds to a part of the CICS API, except for ABENDs and exceptions. For example, the Task class provides a set of methods and variables that correspond to a CICS task.
Errors and Exceptions
The Java language defines both exceptions and errors as subclasses of the class Throwable. JCICS defines CicsError as a subclass of Error. CicsError is the superclass for all the other CICS error classes, which are used for severe errors.

JCICS defines CicsException as a subclass of Exception. CicsException is the superclass for all the CICS exception classes (including the CicsConditionException classes such as InvalidQueueIdException, which represents the CICS QIDERR condition).