uk.ac.starlink.task

Class TerminalInvoker

java.lang.Object

uk.ac.starlink.task.TerminalInvoker

public class TerminalInvoker
extends Object

Invokes Task objects in a way suitable for use from the main method, using a command line interface. The Task invoke methods are invoked and may throw any exception; UsageException and ExecutionException will be treated specially (a sanitised error message without stacktrace will be presented to the user).

Author:

Mark Taylor (Starlink)

Constructor Summary

Constructors

Constructor and Description
TerminalInvoker(String toolname, Map<String,Task> taskmap) Creates a new invoker based on the given class with a given name.

Method Summary

Modifier and Type	Method and Description
static String	getTaskUsage(Task task) Returns a usage string for a given task.
void	invoke(String[] args) Invokes a method from this TerminalInvoker's class.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TerminalInvoker

public TerminalInvoker(String toolname,
                       Map<String,Task> taskmap)

Creates a new invoker based on the given class with a given name. This should generally be invoked from a main method - in the event of an error it will call System.exit rather than returning.

Parameters:

toolname - the name of this tool, used for user messages

taskmap - map of task names to Task objects

Method Detail

invoke

public void invoke(String[] args)
            throws Exception

Invokes a method from this TerminalInvoker's class. The first element of the args identifies the method to be called - it is a case-insensitive version of the name of a method in the class. Subsequent elements are passed (as an args.length-1 element array of Strings) to the method in question. In the event of any trouble (e.g. unknown task, task method throws an exception) a message is printed to standard error and the JVM exits.

Parameters:

args - the arguments identifying what method to call and what arguments to pass to it

Throws:

Exception

getTaskUsage

public static String getTaskUsage(Task task)

Returns a usage string for a given task. This contains only a symbolic representation of the parameter names, not the task name itself.

Parameters:

task - task

Returns:

usage string