/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.camel.component.javaspace;

import java.io.IOException;
import java.rmi.RMISecurityManager;

import net.jini.core.discovery.LookupLocator;
import net.jini.core.entry.Entry;
import net.jini.core.lookup.ServiceRegistrar;
import net.jini.core.lookup.ServiceTemplate;
import net.jini.core.transaction.Transaction;
import net.jini.core.transaction.TransactionFactory;
import net.jini.core.transaction.server.TransactionManager;

/**
 * @version $Revision: 15488 $
 */
public class TransactionHelper {
    private static TransactionHelper me;

    private String uri;
    private TransactionManager trManager;

    public TransactionHelper(String uri) {
        this.uri = uri;
    }

    public static TransactionHelper getInstance(String uri) {
        if (me == null) {
            me = new TransactionHelper(uri);
        }
        return me;
    }

    /**
     * getJiniTransaction Returns a transaction manager proxy.
     * 
     * @param timeout - The length of time our transaction should live before timing out.
     * @return Transaction.Created
     * @throws Exception can be thrown
     */
    public Transaction.Created getJiniTransaction(long timeout) throws Exception {
        if (null == trManager) {
            trManager = findTransactionManager(uri);
        }
        Transaction.Created tCreated = TransactionFactory.create(trManager, timeout);
        return tCreated;
    }

    private TransactionManager findTransactionManager(String uri) throws IOException, ClassNotFoundException {
        if (System.getSecurityManager() == null) {
            System.setSecurityManager(new RMISecurityManager());
        }

        // Creating service template to find transaction manager service by matching fields.
        Class<?>[] classes = new Class<?>[] {net.jini.core.transaction.server.TransactionManager.class};
        // Name sn = new Name("*");
        ServiceTemplate tmpl = new ServiceTemplate(null, classes, new Entry[] {});

        // Creating a lookup locator
        LookupLocator locator = new LookupLocator(uri);
        ServiceRegistrar sr = locator.getRegistrar();

        TransactionManager tm = (TransactionManager) sr.lookup(tmpl);
        return tm;
    }

}
