/*

 * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.jndi.url.rmi;

import java.util.Hashtable;

import javax.naming.*;

import javax.naming.spi.ObjectFactory;

/**

 * An RMI URL context factory creates contexts that can resolve names

 * that are RMI URLs as defined by rmiURLContext.

 * In addition, if given a specific RMI URL (or an array of them), the

 * factory will resolve all the way to the named registry or object.

 *

 * @author Scott Seligman

 *

 * @see rmiURLContext

 */

public class rmiURLContextFactory implements ObjectFactory {

    public Object getObjectInstance(Object urlInfo, Name name,

                                    Context nameCtx, Hashtable<?,?> env)

            throws NamingException

    {

        if (urlInfo == null) {

            return (new rmiURLContext(env));

        } else if (urlInfo instanceof String) {

            return getUsingURL((String)urlInfo, env);

        } else if (urlInfo instanceof String[]) {

            return getUsingURLs((String[])urlInfo, env);

        } else {

            throw (new ConfigurationException(

                    "rmiURLContextFactory.getObjectInstance: " +

                    "argument must be an RMI URL String or an array of them"));

        }

    }

    private static Object getUsingURL(String url, Hashtable<?,?> env)

            throws NamingException

    {

        rmiURLContext urlCtx = new rmiURLContext(env);

        try {

            return urlCtx.lookup(url);

        } finally {

            urlCtx.close();

        }

    }

    /*

     * Try each URL until lookup() succeeds for one of them.

     * If all URLs fail, throw one of the exceptions arbitrarily.

     * Not pretty, but potentially more informative than returning null.

     */

    private static Object getUsingURLs(String[] urls, Hashtable<?,?> env)

            throws NamingException

    {

        if (urls.length == 0) {

            throw (new ConfigurationException(

                    "rmiURLContextFactory: empty URL array"));

        }

        rmiURLContext urlCtx = new rmiURLContext(env);

        try {

            NamingException ne = null;

            for (int i = 0; i < urls.length; i++) {

                try {

                    return urlCtx.lookup(urls[i]);

                } catch (NamingException e) {

                    ne = e;

                }

            }

            throw ne;

        } finally {

            urlCtx.close();

        }

    }

}