org.unix4j.variable

Class MapVariableResolver

java.lang.Object

org.unix4j.variable.MapVariableResolver

All Implemented Interfaces:

VariableResolver

public class MapVariableResolver
extends Object
implements VariableResolver

Variable resolver based on an existing map, where the keys may or may not be prefixed with the variable dollar sign '$'. This class is very similar to SimpleVariableResolver but it is used when a map with name/value for the variables exists already, possibly with a slightly different key (for instance without the dollar prefix). Subclasses may want to override the getMapKeyForVariableName(String) method to change the default assumption about the map keys.

Constructor Summary

Constructors

Constructor and Description
MapVariableResolver(Map<?,?> nameToValue) Constructor with name-to-value map.

Method Summary

Methods

Modifier and Type	Method and Description
static MapVariableResolver	getEnv() Returns a variable resolver for the ENV variables.
String	getMapKeyForVariableName(String variableName) Returns the map key for a given variable name.
static MapVariableResolver	getSystemProperties() Returns a variable resolver for the system properties.
Object	getValue(String name) Returns the value currently set for the variable given by its name, or null if no such variable exists.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

MapVariableResolver

public MapVariableResolver(Map<?,?> nameToValue)

Constructor with name-to-value map.

Parameters:

nameToValue - the map with variable names as keys

Method Detail

getEnv

public static MapVariableResolver getEnv()

Returns a variable resolver for the ENV variables.

Returns:

a variable resolver for the ENV variables.

See Also:

System.getenv()

getSystemProperties

public static MapVariableResolver getSystemProperties()

Returns a variable resolver for the system properties.

Returns:

a variable resolver for the system properties

See Also:

System.getProperties()

getMapKeyForVariableName

public String getMapKeyForVariableName(String variableName)

Returns the map key for a given variable name. If the variable name starts with a dollar sign '$', the name without dollar prefix is returned. Otherwise, the variable name is returned unchanged.

Parameters:

variableName - the variable name, usually prefixed with a dollar sign '$'

Returns:

the variable name without dollar prefix

getValue

public Object getValue(String name)

Description copied from interface: VariableResolver

Returns the value currently set for the variable given by its name, or null if no such variable exists.

Specified by:

getValue in interface VariableResolver

Parameters:

name - the variable name

Returns:

the value of the variable, or null if the variable does not exist

toString

public String toString()

Overrides:

toString in class Object