/*
 * Copyright 2013 Red Hat Inc. and/or its affiliates and other contributors.
 *
 * Licensed 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.switchyard.component.bpel.exchange;

import java.util.List;

import org.switchyard.ServiceDomain;
import org.switchyard.common.util.ProviderRegistry;

/**
 * Creates BPELExchangeHandlers via the JDK ServiceLoader mechanism.
 *
 */
public abstract class BPELExchangeHandlerFactory {

    private static final BPELExchangeHandlerFactory INSTANCE;
    static {
        List<BPELExchangeHandlerFactory> services = ProviderRegistry.getProviders(BPELExchangeHandlerFactory.class);
        INSTANCE = services.iterator().next();
    }

    /**
     * Creates a new BPELExchangeHandler in the specified ServiceDomain.
     * 
     * @param serviceDomain the specified ServiceDomain
     * @return the BPELExchangeHandler
     */
    public abstract BPELExchangeHandler newBPELExchangeHandler(ServiceDomain serviceDomain);

    /**
     * Returns the singleton instance of the BPELExchangeHandlerFactory.
     * 
     * @return the singleton instance
     */
    public static BPELExchangeHandlerFactory instance() {
        return INSTANCE;
    }

}
