org/objectweb/proactive/core/component/controller/AbstractRequestHandler.java

/* 
 * ################################################################
 * 
 * ProActive: The Java(TM) library for Parallel, Distributed, 
 *            Concurrent computing with Security and Mobility
 * 
 * Copyright (C) 1997-2007 INRIA/University of Nice-Sophia Antipolis
 * Contact: proactive@objectweb.org
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 *  
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 * USA
 *  
 *  Initial developer(s):               The ProActive Team
 *                        http://www.inria.fr/oasis/ProActive/contacts.html
 *  Contributor(s): 
 * 
 * ################################################################
 */ 
package org.objectweb.proactive.core.component.controller;

import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;

import org.objectweb.fractal.api.Component;
import org.objectweb.fractal.api.NoSuchInterfaceException;
import org.objectweb.fractal.api.control.AttributeController;
import org.objectweb.proactive.core.ProActiveRuntimeException;
import org.objectweb.proactive.core.component.Constants;
import org.objectweb.proactive.core.component.Fractive;
import org.objectweb.proactive.core.component.identity.ProActiveComponent;
import org.objectweb.proactive.core.component.request.ComponentRequest;
import org.objectweb.proactive.core.mop.MethodCallExecutionFailedException;


public abstract class AbstractRequestHandler implements RequestHandler,
    Serializable {
    private RequestHandler nextHandler = null;
    protected ProActiveComponent owner;

    /*
     * @see org.objectweb.proactive.core.component.controller.RequestHandler#nextHandler()
     */
    public RequestHandler nextHandler() {
        return nextHandler;
    }

    /*
     * @see org.objectweb.proactive.core.component.controller.RequestHandler#setNextHandler(org.objectweb.proactive.core.component.controller.RequestHandler)
     */
    public void setNextHandler(RequestHandler handler) {
        nextHandler = handler;
    }

    public Object handleRequest(ComponentRequest request)
        throws MethodCallExecutionFailedException, InvocationTargetException {
        if (request.getMethodCall().getComponentMetadata()
                       .getComponentInterfaceName().equals(getFcItfName()) &&
                request.getTargetClass().isAssignableFrom(this.getClass())) {
            return request.getMethodCall().execute(this);
        }
        if (nextHandler() != null) {
            return nextHandler().handleRequest(request);
        }

        // special case for attribute controllers for primitive components
        if (AttributeController.class.isAssignableFrom(request.getTargetClass()) &&
                isPrimitive()) {
            // delegate to implementation
            return request.getMethodCall()
                          .execute(((ProActiveComponent) getFcItfOwner()).getReferenceOnBaseObject());
        }
        throw new MethodCallExecutionFailedException(
            "cannot find a suitable handler for this request");
    }

    abstract public String getFcItfName();

    public Component getFcItfOwner() {
        return owner;
    }

    protected String getHierarchicalType() {
        try {
            return Fractive.getComponentParametersController((ProActiveComponent) getFcItfOwner())
                           .getComponentParameters().getHierarchicalType();
        } catch (NoSuchInterfaceException e) {
            throw new ProActiveRuntimeException(
                "There is no component parameters controller for this component");
        }
    }

    protected boolean isPrimitive() {
        return Constants.PRIMITIVE.equals(getHierarchicalType());
    }

    protected boolean isComposite() {
        return Constants.COMPOSITE.equals(getHierarchicalType());
    }
}

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