org.apache.commons.discovery.tools
Class ResourceUtils
java.lang.Object
org.apache.commons.discovery.tools.ResourceUtils
public class ResourceUtils
extends java.lang.Object
Mechanisms to locate and load a class.
The load methods locate a class only.
The find methods locate a class and verify that the
class implements an given interface or extends a given class.
- Richard A. Sitze
- Craig R. McClanahan
- Costin Manolache
static String | getPackageName(Class clazz) - Get package name.
|
static Resource | getResource(Class spi, String resourceName, ClassLoaders loaders) - Load the resource
resourceName .
|
static Properties | loadProperties(Class spi, String propertiesFileName, ClassLoaders classLoaders) - Load named property file, optionally qualifed by spi's package name
as per Class.getResource.
|
getPackageName
public static String getPackageName(Class clazz)
Get package name.
Not all class loaders 'keep' package information,
in which case Class.getPackage() returns null.
This means that calling Class.getPackage().getName()
is unreliable at best.
getResource
public static Resource getResource(Class spi,
String resourceName,
ClassLoaders loaders)
throws DiscoveryException
Load the resource resourceName
.
Try each classloader in succession,
until first succeeds, or all fail.
If all fail and resouceName
is not absolute
(doesn't start with '/' character), then retry with
packageName/resourceName
after changing all
'.' to '/'.
resourceName
- The name of the resource to load.
loadProperties
public static Properties loadProperties(Class spi,
String propertiesFileName,
ClassLoaders classLoaders)
throws DiscoveryException
Load named property file, optionally qualifed by spi's package name
as per Class.getResource.
A property file is loaded using the following sequence of class loaders:
- Thread Context Class Loader
- DiscoverSingleton's Caller's Class Loader
- SPI's Class Loader
- DiscoverSingleton's (this class) Class Loader
- System Class Loader
propertiesFileName
- The property file name.
- Instance of a class implementing the SPI.
DiscoveryException
- Thrown if the name of a class implementing
the SPI cannot be found, if the class cannot be loaded and
instantiated, or if the resulting class does not implement
(or extend) the SPI.
Copyright (c) 2002 - Apache Software Foundation