org.openamf.invoker.EJBServiceInvoker.java Source code

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Here is the source code for org.openamf.invoker.EJBServiceInvoker.java

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/*
 * www.openamf.org
 *
 * Distributable under LGPL license.
 * See terms of license at gnu.org.
 */

package org.openamf.invoker;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import javax.ejb.EJBHome;
import javax.ejb.EJBMetaData;
import javax.ejb.EJBObject;
import javax.ejb.Handle;
import javax.naming.InitialContext;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;

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

/**
 * Simple EJB Service Invoker
 *
 * @author Jason Calabrese <jasonc@missionvi.com>
 * @author Roberto Saccon <saccon@users.sourceforge.net>
 * @version $Revision: 1.14 $, $Date: 2003/12/18 02:31:49 $
 */
public class EJBServiceInvoker extends JavaServiceInvoker {

    private static Log log = LogFactory.getLog(EJBServiceInvoker.class);

    private Object home = null;
    private boolean persistService = false;

    public EJBServiceInvoker(ServiceRequest request, HttpServletRequest httpServletRequest,
            ServletContext servletContex) {

        super(request, httpServletRequest, servletContex);
    }

    public Object invokeService() throws ServiceInvocationException {
        Object serviceResult = null;
        try {
            Object ejb = null;

            if (persistService) {
                log.debug("Trying to get Handle from persistentObject");
                Handle handle = (Handle) getPersistentServiceObject();
                if (handle != null) {
                    log.debug("Got Handle from persistentObject");
                    ejb = handle.getEJBObject();
                }
            }

            if (ejb == null) {
                if (home == null) {
                    log.warn("Home is NULL - unable to find EJB " + request.getServiceName());
                    return null;
                }
                Method ejbCreateMethod = home.getClass().getMethod("create", new Class[0]);
                log.info("Calling Create Method: " + request.getServiceName());
                ejb = ejbCreateMethod.invoke(home, new Object[0]);
            }

            serviceResult = invokeServiceMethod(ejb, ejb.getClass(), request.getServiceMethodName(),
                    request.getParameters());

            if (persistService) {
                if (ejb instanceof EJBObject) {
                    log.debug("setting persistentObject = Handle");
                    setPersistentServiceObject(((EJBObject) ejb).getHandle());
                }
            }

        } catch (InvocationTargetException e) {
            //use the cause since the exception is thrown when 
            //the service method throws an exception
            throw new ServiceInvocationException(request, e.getTargetException());
        } catch (Exception e) {
            throw new ServiceInvocationException(request, e);
        }
        return serviceResult;
    }

    private boolean checkPersistService(Object home) throws Exception {
        boolean persistService = false;
        if (home instanceof EJBHome) {
            EJBMetaData metaData = ((EJBHome) home).getEJBMetaData();
            if (metaData.isSession()) {
                if (metaData.isStatelessSession()) {
                    log.debug("Stateless Session Bean");
                    persistService = false;
                } else {
                    log.debug("Stateful Session Bean");
                    persistService = true;
                }
            } else {
                log.debug("Not Session Bean, assume Entity EJB");
                persistService = true;
            }
        }

        return persistService;
    }

    public boolean getPersistService() {
        return persistService;
    }

    public boolean supports(ServiceRequest request) {
        boolean supports = false;
        try {
            getHome(request);
            supports = true;
        } catch (Exception e) {
        }

        return supports;
    }

    /* Used to check if this is a persistent service (Stateful Session Bean or Entity Bean)
     * @see org.openamf.invoker.ServiceInvoker#prepare(org.openamf.ServiceRequest)
     */
    public void prepare(ServiceRequest request) {
        try {
            persistService = checkPersistService(getHome(request));
        } catch (Exception e) {
        }
    }

    private Object getHome(ServiceRequest request) throws Exception {
        InitialContext context = new InitialContext();
        if (home == null) {
            home = context.lookup(request.getServiceName());
        }
        return home;
    }
}