com.persistit.util

Class ArgParser

java.lang.Object

com.persistit.util.ArgParser

public class ArgParser
extends Object

A simple command line argument parser that provides primitive type conversion and value checking. An application passes a template and the command line argument array to the constructor of this class. The constructor validates the argument list. Subsequently the application can access specific fields from the command line using the ArgParser's accessor methods.

If the command line includes the argument -? then ArgParser displays a summary of permissible arguments and sets its UsageOnly property to true. The calling application should simply exit if isUsageonly is true for the constructed ArgParser.

Version:

1.0

Constructor Summary

Constructors

Constructor and Description
ArgParser(String progName, String[] args, String[] template) Construct an instance that parses an array of command line arguments according to specifications provided in a template.

Method Summary

Modifier and Type	Method and Description
boolean	booleanValue(int index) Return the boolean value of argument specified by its index in the template
String	getFlags()
int	getIntValue(String fieldName)
long	getLongValue(String fieldName)
String	getStringValue(String fieldName)
String[]	getUnparsedArray() Array of arguments that were not parsed by this template.
List<String>	getUnparsedList() List of the arguments that were not parsed by this template.
int	intValue(int index) Return the integer value of argument specified by its index in the template
boolean	isFlag(int ch)
boolean	isSpecified(String fieldName) Indicate whether the value returned for the specified field is the default value.
boolean	isUsageOnly()
long	longValue(int index) Return the long value of argument specified by its index in the template
ArgParser	strict()
String	stringValue(int index) Return the String value of argument specified by its index in the template
String	toString()
void	usage() Display a description of the permissible argument values to System.out.

Methods inherited from class java.lang.Object

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

Constructor Detail

ArgParser

public ArgParser(String progName,
                 String[] args,
                 String[] template)

Construct an instance that parses an array of command line arguments according to specifications provided in a template. The supplied template is an array of specification elements.

Command line arguments are specified by name, not by position. Each argument must either be a flag in the form -X (where X is letter) or a name-value pair in the form argname=value. The permissible flags and argument names are specified by the array of template strings, each of which must have the form:

   _flag|flchar|description
         or
   argname|argtype|description
 

where

flchar

is a single letter that can be used as a flag on the command line. For example, to allow a the flag "-x", use a template string of the form _flags|x|Enable the x option.

argname

Parameter name.

argtype

One of:

 int:defaultvalue:lowbound:highbound
 long:defaultvalue:lowbound:highbound
 String:default
 

Method Detail

toString

public String toString()

Overrides:

toString in class Object

strict

public ArgParser strict()

getUnparsedArray

public String[] getUnparsedArray()

Array of arguments that were not parsed by this template. This array may be passed into another ArgParser for further processing.

Returns:

array of argument strings

getUnparsedList

public List<String> getUnparsedList()

List of the arguments that were not parsed by this template. The list is modifiable.

Returns:

List of argument strings

usage

public void usage()

Display a description of the permissible argument values to System.out.

isUsageOnly

public boolean isUsageOnly()

Returns:

true if the command line arguments contain a help flag, -?.

isFlag

public boolean isFlag(int ch)

Parameters:

ch - The flag character

Returns:

true if the command line arguments contain the specified flag.

getFlags

public String getFlags()

Returns:

A String containing all the flag characters specified in the command line arguments. For example, if the command line specifies value flags -a -b -c then this method returns "abc".

booleanValue

public boolean booleanValue(int index)

Return the boolean value of argument specified by its index in the template

Parameters:

index -

Returns:

the boolean value for the specified template item

getStringValue

public String getStringValue(String fieldName)

Parameters:

fieldName - Argument name of a String value specification in the template array.

Returns:

The corresponding command line argument, or null if the command line does not name this item.

getIntValue

public int getIntValue(String fieldName)

Parameters:

fieldName - Argument name of an int value specification in the template array.

Returns:

The corresponding command line argument, or null if the command line does not name this item.

intValue

public int intValue(int index)

Return the integer value of argument specified by its index in the template

Parameters:

index -

Returns:

the int value for the specified template item

getLongValue

public long getLongValue(String fieldName)

Parameters:

fieldName - Argument name of a long value specification in the template array.

Returns:

The corresponding command line argument, or null if the command line does not name this item.

longValue

public long longValue(int index)

Return the long value of argument specified by its index in the template

Parameters:

index -

Returns:

the long value for the specified template item

stringValue

public String stringValue(int index)

Return the String value of argument specified by its index in the template

Parameters:

index -

Returns:

the String value for the specified template item

isSpecified

public boolean isSpecified(String fieldName)

Indicate whether the value returned for the specified field is the default value.

Parameters:

fieldName -

Returns:

true if the field contains its default value