visad.util
Class CmdlineGenericConsumer

java.lang.Object
  visad.util.CmdlineGenericConsumer

All Implemented Interfaces:

CmdlineConsumer

Direct Known Subclasses:

Main, TestUtil, UpdateJar

public class CmdlineGenericConsumer
extends Object
implements CmdlineConsumer

Simple implementation of CmdlineConsumer interface which can be extended to easily add command-line parsing to an application.

Constructor Summary

CmdlineGenericConsumer()

Method Summary

int	checkKeyword(String mainName, int thisArg, String[] args) Handle subclass-specific command line options and their arguments.
int	checkOption(String mainName, char ch, String arg) Handle subclass-specific command line options and their arguments.
boolean	finalizeArgs(String mainName) Validate arguments after argument parsing has finished.
void	initializeArgs() Method used to initialize any instance variables which may be changed by a cmdline option.
String	keywordUsage() A short string included in the usage message to indicate valid keywords.
String	optionUsage() A short string included in the usage message to indicate valid options.

Methods inherited from class java.lang.Object

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

Constructor Detail

CmdlineGenericConsumer

public CmdlineGenericConsumer()

Method Detail

initializeArgs

public void initializeArgs()

Method used to initialize any instance variables which may be changed by a cmdline option.

This is needed when arguments are processed inside the constructor. If the first line in the constructor in a class which extends this class is super(args), CmdlineParser will be run before any instance variables for the extending class are initialized.

To ensure all instance variables are properly initialized, place the initialization code in the initializeArgs() method.

Specified by:

initializeArgs in interface CmdlineConsumer

checkOption

public int checkOption(String mainName,
                       char ch,
                       String arg)

Handle subclass-specific command line options and their arguments.

If -abc -d efg -h -1 -i is specified, this method will be called a maximum of 5 times:

• checkOption(mainName, 'a', "bc");
• checkOption(mainName, 'd', "efg");
• checkOption(mainName, 'h', "-1");
• checkOption(mainName, '1', "-i");
• checkOption(mainName, 'i', null);

Note that either of the last two method calls may not happen if the preceeding method call claims to have used the following argument (by returning 2.

For example, if the third call (where ch is set to 'h') returns 0 or 1, the next call will contain '1' and "-i". If, however, the third call returns 2, the next call will contain 'i' and null.

Specified by:

checkOption in interface CmdlineConsumer

Parameters:

mainName - The name of the main class (useful for error messages.)

ch - Option character. If -a is specified on the command line, 'a' would be passed to this method.)

arg - The argument associated with this option.

Returns:

less than 0 to indicate an error
0 to indicate that this option is not used by this class
1 to indicate that only the option was used
2 or greater to indicate that both the option and the argument were used

optionUsage

public String optionUsage()

A short string included in the usage message to indicate valid options. An example might be "[-t type]".

Specified by:

optionUsage in interface CmdlineConsumer

Returns:

A very terse description string.

checkKeyword

public int checkKeyword(String mainName,
                        int thisArg,
                        String[] args)

Handle subclass-specific command line options and their arguments.

Specified by:

checkKeyword in interface CmdlineConsumer

Parameters:

mainName - The name of the main class (useful for error messages.)

thisArg - The index of the current keyword.

args - The full list of arguments.

Returns:

less than 0 to indicate an error
0 to indicate that this argument is not used by this class
1 or more to indicate the number of arguments used

keywordUsage

public String keywordUsage()

A short string included in the usage message to indicate valid keywords.

An example might be "[username] [password]".

Specified by:

keywordUsage in interface CmdlineConsumer

Returns:

A very terse description string.

finalizeArgs

public boolean finalizeArgs(String mainName)

Validate arguments after argument parsing has finished.

This is useful for verifying that all required keywords and options have been specified, that options don't conflict with one another, etc.

Specified by:

finalizeArgs in interface CmdlineConsumer

Parameters:

mainName - The name of the main class (useful for error messages.)

Returns:

true if everything is correct, false if there is a problem.