# All Classes and Interfaces

Class
Description
AbortException
Exception generated when the user signals an intention to abort a task.
AbstractChoiceParameter<T,C>
Abstract superclass for parameters that permit choices from a given list of typed options.
BooleanParameter
Parameter value representing a boolean value.
ChoiceParameter<T>
Parameter whose legal value must be one of a disjunction of given values.
DoubleParameter
Parameter representing a double precision number.
Environment
Defines an execution environment within which tasks can operate.
Executable
Defines an object which does the work of a task without any further user or environment interaction.
ExecutionException
Exception generated when a task does not complete correctly for some known reason.
InputStreamParameter
Parameter which can provide an input stream based on its value.
IntegerParameter
Parameter representing an integer value.
InvokeUtils
Provides some utility functions used by classes which invoke tasks.
LineEnvironment
Execution environment for use from the command line.
LineFormatter
Compact log record formatter.
LineWord
Represents a single word on the command line used as by LineEnvironment.
LongParameter
Parameter representing a long integer value.
MultiChoiceParameter<C>
MultiParameter that returns an array of values from a given typed list of options.
MultiParameter
Marker interface which marks a parameter as one which can have multiple appearances on the command line.
MultiTaskInvoker
Invokes tasks from a command line when the tasks are available from an `ObjectFactory`.
ObjectFactoryParameter<T>
Parameter whose (user-supplied) string values correspond to nicknames from an `ObjectFactory`.
OutputStreamParameter
Parameter for selecting an output stream to write to.
Parameter<T>
A Parameter describes the function of one of a task's parameters.
ParameterValueException
Exception generated when the value of a parameter is invalid.
SingleTaskInvoker
Invoker which only knows how to invoke a single given task.
StringParameter
Parameter for holding string values.
Task
Defines a user-level task.
TaskException
Superclass for exceptions in the task package.
TerminalEnvironment
Implementation of Environment which accepts an initial command line, and communicates with the user using standard input and standard output.
TerminalInvoker
Invokes Task objects in a way suitable for use from the `main` method, using a command line interface.
URLParameter
Parameter representing a URL value.
UsageException
An Exception thrown when a task is invoked with the wrong usage.