org.apache.geronimo.osgi.locator
Class ProviderLocator

java.lang.Object
  org.apache.geronimo.osgi.locator.ProviderLocator

public class ProviderLocator
extends Object

Method Summary

static void	destroy() Cleanup resources on bundle shutdown.
static Object	getService(String iface, Class<?> contextClass, ClassLoader loader) Get a single service instance that matches an interface definition.
static Class<?>	getServiceClass(String iface, Class<?> contextClass, ClassLoader loader) Locate a service class that matches an interface definition.
static List<Class<?>>	getServiceClasses(String iface, Class<?> contextClass, ClassLoader loader) Get a list of service class implementations that match an interface name.
static List<Object>	getServices(String iface, Class<?> contextClass, ClassLoader loader) Get a list of services that match a given interface name.
static void	init(org.osgi.framework.BundleContext c) initialize the tracker statics for this bundle
static Class<?>	loadClass(String className) Utility class for locating a class with OSGi registry support.
static Class<?>	loadClass(String className, Class<?> contextClass) Utility class for locating a class with OSGi registry support.
static Class<?>	loadClass(String className, Class<?> contextClass, ClassLoader loader) Standardized utility method for performing class lookups with support for OSGi registry lookups.
static Class<?>	locate(String providerId) Locate a class by its provider id indicator. .
static List<Class<?>>	locateAll(String providerId) Locate all class files that match a given factory id.
static String	lookupByJREPropertyFile(String path, String property) Perform a service class discovery by looking for a property in a target properties file located in the java.home directory.

Methods inherited from class java.lang.Object

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

Method Detail

init

public static void init(org.osgi.framework.BundleContext c)

initialize the tracker statics for this bundle

Parameters:

c - The starup BundleContext.

destroy

public static void destroy()

Cleanup resources on bundle shutdown.

locate

public static Class<?> locate(String providerId)

Locate a class by its provider id indicator. .

Parameters:

providerId - The provider id (generally, a fully qualified class name).

Returns:

The Class corresponding to this provider id. Returns null if this is not registered or the indicated class can't be loaded.

locateAll

public static List<Class<?>> locateAll(String providerId)

Locate all class files that match a given factory id.

Parameters:

providerId - The target provider identifier.

Returns:

A List containing the class objects corresponding to the provider identifier. Returns an empty list if no matching classes can be located.

loadClass

public static Class<?> loadClass(String className)
                          throws ClassNotFoundException

Utility class for locating a class with OSGi registry support. Uses the thread context classloader as part of the search order.

Parameters:

className - The name of the target class.

Returns:

The loaded class.

Throws:

ClassNotFoundException - Thrown if the class cannot be located.

loadClass

public static Class<?> loadClass(String className,
                                 Class<?> contextClass)
                          throws ClassNotFoundException

Utility class for locating a class with OSGi registry support. Uses the thread context classloader as part of the search order.

Parameters:

className - The name of the target class.

Returns:

The loaded class.

Throws:

ClassNotFoundException - Thrown if the class cannot be located.

loadClass

public static Class<?> loadClass(String className,
                                 Class<?> contextClass,
                                 ClassLoader loader)
                          throws ClassNotFoundException

Standardized utility method for performing class lookups with support for OSGi registry lookups.

Parameters:

className - The name of the target class.

loader - An optional class loader.

Returns:

The loaded class

Throws:

ClassNotFoundException - Thrown if the class cannot be loaded.

getService

public static Object getService(String iface,
                                Class<?> contextClass,
                                ClassLoader loader)
                         throws Exception

Get a single service instance that matches an interface definition.

Parameters:

iface - The name of the required interface.

contextClass - The class requesting the lookup (used for class resolution).

loader - A class loader to use for searching for service definitions and loading classes.

Returns:

The service instance, or null if no matching services can be found.

Throws:

Exception - Thrown for any classloading or exceptions thrown trying to instantiate a service instance.

getServiceClass

public static Class<?> getServiceClass(String iface,
                                       Class<?> contextClass,
                                       ClassLoader loader)
                                throws ClassNotFoundException

Locate a service class that matches an interface definition.

Parameters:

iface - The name of the required interface.

contextClass - The class requesting the lookup (used for class resolution).

loader - A class loader to use for searching for service definitions and loading classes.

Returns:

The located class, or null if no matching services can be found.

Throws:

Exception - Thrown for any classloading exceptions thrown trying to load the class.

ClassNotFoundException

getServices

public static List<Object> getServices(String iface,
                                       Class<?> contextClass,
                                       ClassLoader loader)
                                throws Exception

Get a list of services that match a given interface name. This searches both the current class path and the global repository for matches.

Parameters:

iface - The name of the required interface.

contextClass - The class requesting the lookup (used for class resolution).

loader - A class loader to use for searching for service definitions and loading classes.

Returns:

A list of matching services. Returns an empty list if there are no matches.

Throws:

Exception - Thrown for any classloading or exceptions thrown trying to instantiate a service instance.

getServiceClasses

public static List<Class<?>> getServiceClasses(String iface,
                                               Class<?> contextClass,
                                               ClassLoader loader)
                                        throws Exception

Get a list of service class implementations that match an interface name. This searches both the current class path and the global repository for matches.

Parameters:

iface - The name of the required interface.

contextClass - The class requesting the lookup (used for class resolution).

loader - A class loader to use for searching for service definitions and loading classes.

Returns:

A list of matching provider classes. Returns an empty list if there are no matches.

Throws:

Exception - Thrown for any classloading exceptions thrown trying to load a provider class.

lookupByJREPropertyFile

public static String lookupByJREPropertyFile(String path,
                                             String property)
                                      throws IOException

Perform a service class discovery by looking for a property in a target properties file located in the java.home directory.

Parameters:

path - The relative path to the desired properties file.

property - The name of the required property.

Returns:

The value of the named property within the properties file. Returns null if the property doesn't exist or the properties file doesn't exist.

Throws:

IOException