/* * Copyright (c) 2002-2003 by OpenSymphony * All rights reserved. */package com.opensymphony.workflow.util.ejb.remote;import com.opensymphony.module.propertyset.PropertySet;import com.opensymphony.workflow.*;import java.lang.reflect.Method;import java.rmi.RemoteException;import java.util.Hashtable;import java.util.Iterator;import java.util.Map;import javax.ejb.EJBHome;import javax.naming.InitialContext;import javax.rmi.PortableRemoteObject;/** * Function to execute a remote EJB that implements {@link FunctionProviderRemote}. * A required argument for this function is <code>ejb.location</code>, which specifies * the JNDI location to look up the remote EJB at. * <p> * Note that by default, the EJB will be looked up from a default InitialContext. It is * however possible to specify an environment for the initial context by specifying the * standard JNDI keys as arguments. * <p> * For example, specifying an argument with a name of <code>java.naming.security.principal</code> * and a value of <code>testuser</code> will result in an InitialContext being created with * the user specified as 'testuser'. * * @author $Author: hani $ * @version $Revision: 1.3 $ */public class RemoteEJBFunctionProvider implements FunctionProvider {    //~ Methods ////////////////////////////////////////////////////////////////    public void execute(Map transientVars, Map args, PropertySet ps) throws WorkflowException {        FunctionProviderRemote sessionBean;        String ejbLocation = (String) args.get(AbstractWorkflow.EJB_LOCATION);        Hashtable env = null;        Iterator iter = args.entrySet().iterator();        while (iter.hasNext()) {            Map.Entry entry = (Map.Entry) iter.next();            if (env == null) {                env = new Hashtable();            }            if (((String) entry.getKey()).startsWith("java.naming.")) {                env.put(entry.getKey(), entry.getValue());            }        }        try {            EJBHome home = (EJBHome) PortableRemoteObject.narrow(new InitialContext(env).lookup(ejbLocation), EJBHome.class);            Method create = home.getClass().getMethod("create", new Class[0]);            sessionBean = (FunctionProviderRemote) create.invoke(home, new Object[0]);        } catch (Exception e) {            String message = "Could not get handle to remote EJB at: " + ejbLocation;            throw new WorkflowException(message, e);        }        try {            sessionBean.execute(transientVars, args, ps);        } catch (RemoteException e) {            String message = "Remote exception from EJB at: " + ejbLocation;            throw new WorkflowException(message, e);        }    }}