weka.core

Class ResourceUtils

java.lang.Object

weka.core.ResourceUtils

public class ResourceUtils
extends java.lang.Object

Helper for resources.

Version:

$Revision$

Author:

FracPete (fracpete at waikato dot ac dot nz)

Constructor Summary

Constructors

Constructor and Description
ResourceUtils()

Method Summary

Modifier and Type	Method and Description
static java.lang.Object	forName(java.lang.Class<?> classType, java.lang.String className, java.lang.String[] options) Creates a new instance of an object given it's class name and (optional) arguments to pass to it's setOptions method.
static java.io.File	getWekaHome() Returns the Weka home directory.
static java.util.Properties	readProperties(java.lang.String resourceName) Reads properties that inherit from three locations.
static java.util.Properties	readProperties(java.lang.String resourceName, java.lang.ClassLoader loader) Reads properties that inherit from three locations.

Methods inherited from class java.lang.Object

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

Constructor Detail

ResourceUtils

public ResourceUtils()

Method Detail

forName

public static java.lang.Object forName(java.lang.Class<?> classType,
                                       java.lang.String className,
                                       java.lang.String[] options)
                                throws java.lang.Exception

Creates a new instance of an object given it's class name and (optional) arguments to pass to it's setOptions method. If the object implements OptionHandler and the options parameter is non-null, the object will have it's options set. Example use:

 String classifierName = Utils.getOption('W', options);
 Classifier c = (Classifier)Utils.forName(Classifier.class,
                                          classifierName,
                                          options);
 setClassifier(c);
 

Parameters:

classType - the class that the instantiated object should be assignable to -- an exception is thrown if this is not the case

className - the fully qualified class name of the object

options - an array of options suitable for passing to setOptions. May be null. Any options accepted by the object will be removed from the array.

Returns:

the newly created object, ready for use (if it is an array, it will have size zero).

Throws:

java.lang.Exception - if the class name is invalid, or if the class is not assignable to the desired class type, or the options supplied are not acceptable to the object

readProperties

public static java.util.Properties readProperties(java.lang.String resourceName)
                                           throws java.lang.Exception

Reads properties that inherit from three locations. Properties are first defined in the system resource location (i.e. in the CLASSPATH). These default properties must exist. Properties optionally defined in the user properties location (WekaPackageManager.PROPERTIES_DIR) override default settings. Properties defined in the current directory (optional) override all these settings.

Parameters:

resourceName - the location of the resource that should be loaded. e.g.: "weka/core/Utils.props". (The use of hardcoded forward slashes here is OK - see jdk1.1/docs/guide/misc/resources.html) This routine will also look for the file (in this case) "Utils.props" in the users home directory and the current directory.

Returns:

the Properties

Throws:

java.lang.Exception - if no default properties are defined, or if an error occurs reading the properties files.

readProperties

public static java.util.Properties readProperties(java.lang.String resourceName,
                                                  java.lang.ClassLoader loader)
                                           throws java.lang.Exception

Reads properties that inherit from three locations. Properties are first defined in the system resource location (i.e. in the CLASSPATH). These default properties must exist. Properties optionally defined in the user properties location (WekaPackageManager.PROPERTIES_DIR) override default settings. Properties defined in the current directory (optional) override all these settings.

Parameters:

resourceName - the location of the resource that should be loaded. e.g.: "weka/core/Utils.props". (The use of hardcoded forward slashes here is OK - see jdk1.1/docs/guide/misc/resources.html) This routine will also look for the file (in this case) "Utils.props" in the users home directory and the current directory.

loader - the class loader to use when loading properties

Returns:

the Properties

Throws:

java.lang.Exception - if no default properties are defined, or if an error occurs reading the properties files.

getWekaHome

public static java.io.File getWekaHome()

Returns the Weka home directory.

Returns:

the home directory