uk.ac.starlink.ttools.task

Class LineInvoker

java.lang.Object

uk.ac.starlink.ttools.task.LineInvoker

public class LineInvoker
extends Object

Invokes the Stilts tasks using a LineTableEnvironment.

Since:

15 Aug 2005

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
LineInvoker(String toolName, ObjectFactory<Task> taskFactory) Constructor.

Method Summary

Modifier and Type	Method and Description
static String	getParamHelp(TableEnvironment env, String taskName, Parameter<?> param) Returns a help string for a parameter of one of the tasks known to this application.
static String	getPrefixedParameterUsage(Parameter<?>[] params, String prefix) Returns a usage string for a set of parameters, prefixed by a given string.
static String	getStackSummary(Throwable error) Returns a truncated version of a stack trace for user consumption.
static String	getUnusedWarning(String[] unused) Returns a warning string appropriate for the case when one or more words on the command line are never used by a task.
int	invoke(String[] args, Runnable loggedConfig) Invokes one of the known tasks given a string of command-line words.

Methods inherited from class java.lang.Object

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

Constructor Detail

LineInvoker

public LineInvoker(String toolName,
                   ObjectFactory<Task> taskFactory)

Constructor.

Parameters:

toolName - name of the overall application

taskFactory - factory which can create the tasks known to the application

Method Detail

invoke

public int invoke(String[] args,
                  Runnable loggedConfig)

Invokes one of the known tasks given a string of command-line words. The args string will typically come straight out of a static main() method. A callback may be supplied to perform configuration that has to be done after logging configuration - presumably because it does some logging itself. It is executed synchronously.

Parameters:

args - argument list

loggedConfig - callback for configuration to be done after logging configuration (may be null)

getStackSummary

public static String getStackSummary(Throwable error)

Returns a truncated version of a stack trace for user consumption. This gives the error message for each throwable in the cause chain, but not line numbers etc.

Parameters:

error - exception to summarise

Returns:

multiline text summary

getPrefixedParameterUsage

public static String getPrefixedParameterUsage(Parameter<?>[] params,
                                               String prefix)

Returns a usage string for a set of parameters, prefixed by a given string.

Parameters:

params - parameter array

prefix - string to prepend to the first line

Returns:

usage string

getParamHelp

public static String getParamHelp(TableEnvironment env,
                                  String taskName,
                                  Parameter<?> param)

Returns a help string for a parameter of one of the tasks known to this application. May include extended usage information. Consider the result to be a formatted string, that is, one which contains newlines to keep line lengths down to a reasonable level.

Parameters:

env - execution environment

taskName - task nickname - may be null if heading is not required

param - parameter for which usage information is required

Returns:

usage message

getUnusedWarning

public static String getUnusedWarning(String[] unused)

Returns a warning string appropriate for the case when one or more words on the command line are never used by a task.

Parameters:

unused - unused words

Returns:

warning lines