weka.core

Class Environment

java.lang.Object

weka.core.Environment

All Implemented Interfaces:

RevisionHandler

Direct Known Subclasses:

JobEnvironment

public class Environment
extends java.lang.Object
implements RevisionHandler

This class encapsulates a map of all environment and java system properties. There are methods for adding and removing variables to this Environment object as well as to the system wide global environment. There is also a method for replacing key names (enclosed by ${}) with their associated value in Strings.

Version:

$Revision: 13892 $

Author:

Mark Hall (mhall{[at]}pentaho{[dot]}com)

Constructor Summary

Constructors

Constructor and Description
Environment() Constructs a new Environment object with all environment variables and java properties set.
Environment(Environment other) Constructor that makes a new Environment object containing all the entries in the supplied one

Method Summary

Modifier and Type	Method and Description
void	addVariable(java.lang.String key, java.lang.String value) Add a variable to the internal map of this properties object.
void	addVariableSystemWide(java.lang.String key, java.lang.String value) Add a a variable to the internal map of this properties object and to the global system-wide environment;
static boolean	containsEnvVariables(java.lang.String source) Tests for the presence of environment variables.
java.lang.String	getRevision() Returns the revision string.
static Environment	getSystemWide() Get the singleton system-wide (visible to every class in the running VM) set of environment variables.
java.util.Set<java.lang.String>	getVariableNames() Get the names of the variables (keys) stored in the internal map.
java.lang.String	getVariableValue(java.lang.String key) Get the value for a particular variable.
static void	main(java.lang.String[] args) Main method for testing this class.
void	removeVariable(java.lang.String key) Remove a named variable from the map.
java.lang.String	substitute(java.lang.String source) Substitute a variable names for their values in the given string.

Methods inherited from class java.lang.Object

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

Constructor Detail

Environment

public Environment()

Constructs a new Environment object with all environment variables and java properties set.

Environment

public Environment(Environment other)

Constructor that makes a new Environment object containing all the entries in the supplied one

Parameters:

other - the Environment object to copy to this one

Method Detail

getSystemWide

public static Environment getSystemWide()

Get the singleton system-wide (visible to every class in the running VM) set of environment variables.

Returns:

the system-wide set of environment variables.

containsEnvVariables

public static boolean containsEnvVariables(java.lang.String source)

Tests for the presence of environment variables.

Parameters:

source - the string to test

Returns:

true if the argument contains one or more environment variables

substitute

public java.lang.String substitute(java.lang.String source)
                            throws java.lang.Exception

Substitute a variable names for their values in the given string.

Parameters:

source - the source string to replace variables in

Returns:

a String with all variable names replaced with their values

Throws:

java.lang.Exception - if an unknown variable name is encountered

addVariable

public void addVariable(java.lang.String key,
                        java.lang.String value)

Add a variable to the internal map of this properties object.

Parameters:

key - the name of the variable

value - its value

addVariableSystemWide

public void addVariableSystemWide(java.lang.String key,
                                  java.lang.String value)

Add a a variable to the internal map of this properties object and to the global system-wide environment;

Parameters:

key - the name of the variable

value - its value

removeVariable

public void removeVariable(java.lang.String key)

Remove a named variable from the map.

Parameters:

key - the name of the varaible to remove.

getVariableNames

public java.util.Set<java.lang.String> getVariableNames()

Get the names of the variables (keys) stored in the internal map.

Returns:

a Set of variable names (keys)

getVariableValue

public java.lang.String getVariableValue(java.lang.String key)

Get the value for a particular variable.

Parameters:

key - the name of the variable to get

Returns:

the associated value or null if this variable is not in the internal map

main

public static void main(java.lang.String[] args)

Main method for testing this class.

Parameters:

args - a list of strings to replace variables in (e.g. "\${os.name} "\${java.version}")

getRevision

public java.lang.String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Returns:

the revision