org.apache.openejb.javaee.api.activator.org.apache.openejb.javaee.api.locator

Class ProviderLocator

java.lang.Object

org.apache.openejb.javaee.api.activator.org.apache.openejb.javaee.api.locator.ProviderLocator

public class ProviderLocator
extends Object

Method Summary

Modifier and Type	Method and Description
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 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 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

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.

contextClass - The context class to retrive the classloader.

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.

contextClass - The context class to retrive the classloader.

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:

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

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