edu.illinois.cs.cogcomp.ner

Class AbstractMain

java.lang.Object

java.lang.Thread

edu.illinois.cs.cogcomp.ner.AbstractMain

All Implemented Interfaces:

Runnable

Direct Known Subclasses:

Main

public abstract class AbstractMain
extends Thread

This is an abstract base class that can be used build a menu driven command line interface. Processing state (e.g. what submenu you are on) is maintained by subclasses. This class extends Thread, the thread starts in the constructure.

Menus and prompts are displayed on standard output. The inputMenu method is called to render the current menu to standard out. When the user issues a selection on standard output, the processCommand method is called to perform whatever required action.

There are also abstract methods that parse command line arguments (processArguments and to present the command line syntax (getCommandSyntax) in the event of a command line argument error. Any exception thrown by the processArguments method will result in the command line syntax being displayed, then the system will exit. Subclasses may also call the errorProcessingArguments method with a message argument to provide a custom error message. If the processArguments method throws an exception, the message associated with that exception will be displayed along with the command line syntax.

Author:

redman

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractMain(String[] args) This class takes a list of command line arguments.

Method Summary

Modifier and Type	Method and Description
protected void	errorProcessingArguments(String message) this method is called if there is a catastrophic error processing arguments.
protected abstract String	getCommandSyntax() This method will return a string which documents the command line arguments before a system exit.
protected abstract void	inputMenu() present the input menu to standard out.
protected abstract int	processArgument(String[] args, int current) This will process the current argument, and return the integer indicating the next argument to be processed.
protected void	processArguments(String[] args) this method will traverse all arguments calling the processArgument method with each argument.
protected abstract void	processCommand(String line) Process the command provided in line.
void	run() Present a menu indicating the current display and providing an input menu, fetch the next line, the process the assumed command there.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractMain

protected AbstractMain(String[] args)

This class takes a list of command line arguments. Typically a configuration file will be passed in.

Parameters:

args - the arguments.

Method Detail

errorProcessingArguments

protected void errorProcessingArguments(String message)

this method is called if there is a catastrophic error processing arguments. It will report the message, report the command syntax, and exit.

Parameters:

message - the error message to report before the command line syntax.

processArguments

protected void processArguments(String[] args)

this method will traverse all arguments calling the processArgument method with each argument.

Parameters:

args - the array of arguments.

run

public void run()

Present a menu indicating the current display and providing an input menu, fetch the next line, the process the assumed command there.

Specified by:

run in interface Runnable

Overrides:

run in class Thread

processCommand

protected abstract void processCommand(String line)
                                throws Exception

Process the command provided in line.

Parameters:

line - the command to process.

Throws:

Exception

inputMenu

protected abstract void inputMenu()

present the input menu to standard out.

getCommandSyntax

protected abstract String getCommandSyntax()

This method will return a string which documents the command line arguments before a system exit.

Returns:

the command line systex documented in a string.

processArgument

protected abstract int processArgument(String[] args,
                                       int current)
                                throws Exception

This will process the current argument, and return the integer indicating the next argument to be processed. This mechanism will allow the implementer to pull additional arguments off the stack as needed.

Parameters:

args - the arguments.

current - the index of the current argument.

Returns:

the index of the next argument.

Throws:

Exception - if fatal error, throw an exception will cause a system exit.