org.codehaus.plexus.interpolation.fixed
Class EnvarBasedValueSource

java.lang.Object
  org.codehaus.plexus.interpolation.fixed.EnvarBasedValueSource

All Implemented Interfaces:

FixedValueSource

public class EnvarBasedValueSource
extends Object
implements FixedValueSource

ValueSource which resolves expressions against the environment variables available from the underlying operating system (and possibly, the shell environment that created the present Java process). If the expression starts with 'env.', this prefix is trimmed before resolving the rest as an environment variable name.

Version:

$Id$

Constructor Summary

EnvarBasedValueSource()
Create a new value source for interpolation based on shell environment variables.

EnvarBasedValueSource(boolean caseSensitive)
Create a new value source for interpolation based on shell environment variables.

Method Summary

Object

getValue(String expression, InterpolationState interpolationState) If the expression starts with 'env.' then trim this prefix.

Methods inherited from class java.lang.Object

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

Constructor Detail

EnvarBasedValueSource

public EnvarBasedValueSource()
                      throws IOException

Create a new value source for interpolation based on shell environment variables. In this case, envar keys ARE CASE SENSITIVE.

Throws:

IOException

EnvarBasedValueSource

public EnvarBasedValueSource(boolean caseSensitive)
                      throws IOException

Create a new value source for interpolation based on shell environment variables.

Parameters:

caseSensitive - Whether the environment variable key should be treated in a case-sensitive manner for lookups

Throws:

IOException

Method Detail

getValue

public Object getValue(String expression,
                       InterpolationState interpolationState)

If the expression starts with 'env.' then trim this prefix. Next, resolve the (possibly trimmed) expression as an environment variable name against the collection of environment variables that were read from the operating system when this ValueSource instance was created.

Specified by:

getValue in interface FixedValueSource

Parameters:

expression - envar expression, like 'HOME' or 'env.HOME'

Returns:

the environment variable value for the given expression