Library structure

Each JCICS library component falls into one of four categories:
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).

See Error handling and abnormal termination for further information.