Package com.beust.jcommander.defaultprovider

Class EnvironmentVariableDefaultProvider

java.lang.Object

com.beust.jcommander.defaultprovider.EnvironmentVariableDefaultProvider

All Implemented Interfaces:

IDefaultProvider

public final class EnvironmentVariableDefaultProvider
extends Object
implements IDefaultProvider

A default provider that reads its default values from an environment variable. A prefix pattern can be provided to indicate how options are identified. The default pattern -/ mandates that options MUST start with either a dash or a slash. Options can have values separated by whitespace. Values can contain whitespace as long as they are single-quoted or double-quoted. Otherwhise whitespace identifies the end of a value.

Field Summary

Fields

Modifier and Type	Field	Description
private static final String	DEFAULT_PREFIXES_PATTERN
private static final String	DEFAULT_VARIABLE_NAME
private final String	environmentVariableValue
private final String	optionPrefixesPattern

Constructor Summary

Constructors

Constructor	Description
EnvironmentVariableDefaultProvider()	Creates a default provider reading the environment variable JCOMMANDER_OPTS using the prefixes pattern -/.
EnvironmentVariableDefaultProvider(String environmentVariableName, String optionPrefixes)	Creates a default provider reading the specified environment variable using the specified prefixes pattern.
EnvironmentVariableDefaultProvider(String environmentVariableName, String optionPrefixes, Function<String,String> resolver)	For Unit Tests Only: Allows to mock the resolver, as Java cannot set environment variables.

Method Summary

Modifier and Type	Method	Description
final String	getDefaultValueFor(String optionName)

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_VARIABLE_NAME

private static final String DEFAULT_VARIABLE_NAME

See Also:

• Constant Field Values

DEFAULT_PREFIXES_PATTERN

private static final String DEFAULT_PREFIXES_PATTERN

See Also:

• Constant Field Values

environmentVariableValue

private final String environmentVariableValue

optionPrefixesPattern

private final String optionPrefixesPattern

Constructor Details

EnvironmentVariableDefaultProvider

public EnvironmentVariableDefaultProvider()

Creates a default provider reading the environment variable JCOMMANDER_OPTS using the prefixes pattern -/.

EnvironmentVariableDefaultProvider

public EnvironmentVariableDefaultProvider(String environmentVariableName,
 String optionPrefixes)

Creates a default provider reading the specified environment variable using the specified prefixes pattern.

Parameters:

environmentVariableName - The name of the environment variable to read (e. g. "JCOMMANDER_OPTS"). Must not be null.

optionPrefixes - A set of characters used to indicate the start of an option (e. g. "-/" if option names may start with either dash or slash). Must not be null.

EnvironmentVariableDefaultProvider

EnvironmentVariableDefaultProvider(String environmentVariableName,
 String optionPrefixes,
 Function<String,String> resolver)

For Unit Tests Only: Allows to mock the resolver, as Java cannot set environment variables.

Parameters:

environmentVariableName - The name of the environment variable to read. May be null if the passed resolver doesn't use it (e. g. Unit Test).

optionPrefixes - A set of characters used to indicate the start of an option (e. g. "-/" if option names may start with either dash or slash). Must not be null.

resolver - Reads the value from the environment variable (e. g. System::getenv). Must not be null.

Method Details

getDefaultValueFor

public final String getDefaultValueFor(String optionName)

Specified by:

getDefaultValueFor in interface IDefaultProvider

Parameters:

optionName - The name of the option as specified in the names() attribute of the @Parameter option (e.g. "-file").

Returns:

the default value for this option.