[Openbus-cvs-commits] Openbus/OpenbusJBI/src/java/org/openbus/jbi/loader CompositeClassLoader.java,NONE,1.1 DelegateClassLoader.java,NONE,1.1

[Esteban S. <es...@us...>]

Update of /cvsroot/openbus/Openbus/OpenbusJBI/src/java/org/openbus/jbi/loader
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv24925/src/java/org/openbus/jbi/loader

Added Files:
	CompositeClassLoader.java DelegateClassLoader.java 
Log Message:
Adding custom class loaders

--- NEW FILE: DelegateClassLoader.java ---
/*
 * Copyright 2001-2005 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.openbus.jbi.loader;

import java.net.URL;
import java.net.URLClassLoader;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * ClassLoader with a configurable delegation model
 * 
 * @author <a href="mailto:es...@op...">Esteban Sancho </a>
 */
public class DelegateClassLoader extends URLClassLoader {
    private static final Log log = LogFactory.getLog(DelegateClassLoader.class);

    private boolean parentFirst;

    public DelegateClassLoader(URL[] urls_, boolean parentFirst_) {
        super(urls_);
        parentFirst = parentFirst_;
    }

    public DelegateClassLoader(URL[] urls_, ClassLoader parent_,
            boolean parentFirst_) {
        super(urls_, parent_);
        parentFirst = parentFirst_;
    }

    public synchronized Class loadClass(String name_, boolean resolve_)
            throws ClassNotFoundException {
        if (parentFirst || isSystemClass(name_)) {
            // default Java 2 implementation
            if (log.isDebugEnabled()) {
                log.debug("Delegating resolution of class " + name_
                        + " to the parent first");
            }
            return super.loadClass(name_, resolve_);
        } else {
            // our custom implementation for resolving self first
            if (log.isDebugEnabled()) {
                log.debug("Trying to resolve class " + name_ + " here first");
            }
            return selfFirstLoadClass(name_, resolve_);
        }
    }

    protected boolean isSystemClass(String name_) {
        boolean isSystem = (name_.startsWith("java."))
                || (name_.startsWith("javax."));
        if (log.isDebugEnabled()) {
            log.debug("Class " + name_ + (isSystem ? " is " : " is not ")
                    + "a system class");
        }
        return isSystem;
    }

    protected Class selfFirstLoadClass(String name_, boolean resolve_)
            throws ClassNotFoundException {
        // First check if the class is already loaded
        Class clazz = findLoadedClass(name_);

        if (clazz == null) {
            try {
                // first look here
                clazz = findClass(name_);
                if (log.isDebugEnabled()) {
                    log.debug("Class " + name_ + " resolved here");
                }
            } catch (ClassNotFoundException e) {
                // If still not found, then delegate to the parent
                if (getParent() != null) {
                    clazz = getParent().loadClass(name_);
                    if (log.isDebugEnabled()) {
                        log.debug("Class " + name_ + " resolved in parent");
                    }
                    // returning in order to don't resolve it again
                    return clazz;
                }
            }
        }

        if (resolve_) {
            resolveClass(clazz);
        }

        return clazz;
    }
}
--- NEW FILE: CompositeClassLoader.java ---
/*
 * Copyright 2001-2005 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.openbus.jbi.loader;

import java.security.SecureClassLoader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * 
 * 
 * @author <a href="mailto:es...@op...">Esteban Sancho </a>
 */
public class CompositeClassLoader extends SecureClassLoader {
    private static final Log log = LogFactory
            .getLog(CompositeClassLoader.class);

    private Collection classLoaders;

    public CompositeClassLoader(ClassLoader parent_) {
        super(parent_);
        classLoaders = new ArrayList();
    }

    public CompositeClassLoader(ClassLoader parent_,
            DelegateClassLoader[] classLoaders_) {
        super(parent_);
        classLoaders = Arrays.asList(classLoaders_);
    }

    public void addClassLoader(DelegateClassLoader loader_) {
        if (log.isDebugEnabled()) {
            log.debug("Adding class loader " + loader_);
        }
        classLoaders.add(loader_);
    }

    public void removeClassLoader(DelegateClassLoader loader_) {
        boolean removed = classLoaders.remove(loader_);
        if (log.isDebugEnabled()) {
            log.debug("Removing class loader " + loader_ + " - Found: "
                    + removed);
        }
    }

    public Class loadClass(String name_) throws ClassNotFoundException {
        return loadClass(name_, true);
    }

    protected synchronized Class loadClass(String name_, boolean resolve_)
            throws ClassNotFoundException {
        // look into the cache
        Class clazz = findLoadedClass(name_);
        if (clazz != null) {
            if (log.isDebugEnabled()) {
                log.debug("Class " + name_ + " was already loaded");
            }
            return clazz;
        }

        // look into the backend class-loaders
        for (Iterator i = classLoaders.iterator(); i.hasNext();) {
            DelegateClassLoader loader = (DelegateClassLoader) i.next();
            try {
                clazz = loader.loadClass(name_, resolve_);
                if (log.isDebugEnabled()) {
                    log.debug("Class " + name_ + " found in class loader: "
                            + loader);
                }
                return clazz;
            } catch (ClassNotFoundException e) {
                if (log.isTraceEnabled()) {
                    log.trace("Class " + name_ + " not found in class loader: "
                            + loader);
                }
            }
        }

        if (log.isDebugEnabled()) {
            log.debug("Class not found: " + name_);
        }

        // @todo i18n
        throw new ClassNotFoundException("Class not found: " + name_);
    }
}