/*******************************************************************************
* Copyright (c) 2008, 2010 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.osgi.framework.adaptor;
import java.io.FileNotFoundException;
import java.net.URL;
import java.util.Enumeration;
import org.eclipse.osgi.baseadaptor.HookRegistry;
/**
* A ClassLoaderDelegateHook hooks into the <code>ClassLoaderDelegate</code>.
* @see ClassLoaderDelegate
* @see HookRegistry#getClassLoaderDelegateHooks()
* @see HookRegistry#addClassLoaderDelegateHook(ClassLoaderDelegateHook)
* @since 3.4
*/
public interface ClassLoaderDelegateHook {
/**
* Called by a {@link ClassLoaderDelegate#findClass(String)} method before delegating to the resolved constraints and
* local bundle for a class load. If this method returns null then normal delegation is done. If this method
* returns a non-null value then the rest of the delegation process is skipped and the returned value is used.
* If this method throws a <code>ClassNotFoundException</code> then the calling
* {@link ClassLoaderDelegate#findClass(String)} method re-throws the exception.
* @param name the name of the class to find
* @param classLoader the bundle class loader
* @param data the bundle data
* @return the class found by this hook or null if normal delegation should continue
* @throws ClassNotFoundException to terminate the delegation and throw an exception
*/
public Class<?> preFindClass(String name, BundleClassLoader classLoader, BundleData data) throws ClassNotFoundException;
/**
* Called by a {@link ClassLoaderDelegate#findClass(String)} method after delegating to the resolved constraints and
* local bundle for a class load. This method will only be called if no class was found
* from the normal delegation.
* @param name the name of the class to find
* @param classLoader the bundle class loader
* @param data the bundle data
* @return the class found by this hook or null if normal delegation should continue
* @throws ClassNotFoundException to terminate the delegation and throw an exception
*/
public Class<?> postFindClass(String name, BundleClassLoader classLoader, BundleData data) throws ClassNotFoundException;
/**
* Called by a {@link ClassLoaderDelegate #findResource(String)} before delegating to the resolved constraints and
* local bundle for a resource load. If this method returns null then normal delegation is done.
* If this method returns a non-null value then the rest of the delegation process is skipped and the returned value is used.
* If this method throws an <code>FileNotFoundException</code> then the delegation is terminated.
* @param name the name of the resource to find
* @param classLoader the bundle class loader
* @param data the bundle data
* @return the resource found by this hook or null if normal delegation should continue
* @throws FileNotFoundException to terminate the delegation
*/
public URL preFindResource(String name, BundleClassLoader classLoader, BundleData data) throws FileNotFoundException;
/**
* Called by a {@link ClassLoaderDelegate} after delegating to the resolved constraints and
* local bundle for a resource load. This method will only be called if no resource was found
* from the normal delegation.
* @param name the name of the resource to find
* @param classLoader the bundle class loader
* @param data the bundle data
* @return the resource found by this hook or null if normal delegation should continue
* @throws FileNotFoundException to terminate the delegation
*/
public URL postFindResource(String name, BundleClassLoader classLoader, BundleData data) throws FileNotFoundException;
/**
* Called by a {@link ClassLoaderDelegate} before delegating to the resolved constraints and
* local bundle for a resource load. If this method returns null then normal delegation is done.
* If this method returns a non-null value then the rest of the delegation process is skipped and the returned value is used.
* If this method throws an <code>FileNotFoundException</code> then the delegation is terminated
* @param name the name of the resource to find
* @param classLoader the bundle class loader
* @param data the bundle data
* @return the resources found by this hook or null if normal delegation should continue
* @throws FileNotFoundException to terminate the delegation
*/
public Enumeration<URL> preFindResources(String name, BundleClassLoader classLoader, BundleData data) throws FileNotFoundException;
/**
* Called by a {@link ClassLoaderDelegate} after delegating to the resolved constraints and
* local bundle for a resource load. This method will only be called if no resources were found
* from the normal delegation.
* @param name the name of the resource to find
* @param classLoader the bundle class loader
* @param data the bundle data
* @return the resources found by this hook or null if normal delegation should continue
* @throws FileNotFoundException to terminate the delegation
*/
public Enumeration<URL> postFindResources(String name, BundleClassLoader classLoader, BundleData data) throws FileNotFoundException;
/**
* Called by a {@link ClassLoaderDelegate} before normal delegation. If this method returns
* a non-null value then the rest of the delegation process is skipped and the returned value
* is used.
* @param name the name of the library to find
* @param classLoader the bundle class loader
* @param data the bundle data
* @return the library found by this hook or null if normal delegation should continue
* @throws FileNotFoundException to terminate the delegation
*/
public String preFindLibrary(String name, BundleClassLoader classLoader, BundleData data) throws FileNotFoundException;
/**
* Called by a {@link ClassLoaderDelegate} after normal delegation. This method will only be called
* if no library was found from the normal delegation.
* @param name the name of the library to find
* @param classLoader the bundle class loader
* @param data the bundle data
* @return the library found by this hook or null if normal delegation should continue
*/
public String postFindLibrary(String name, BundleClassLoader classLoader, BundleData data);
}