/*
 * Copyright 1999-2011 Alibaba Group.
 *  
 * 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 com.alibaba.dubbo.remoting.p2p;

import com.alibaba.dubbo.common.URL;
import com.alibaba.dubbo.common.extension.SPI;
import com.alibaba.dubbo.remoting.RemotingException;

/**
 * Networker. (SPI, Singleton, ThreadSafe)
 * 
 * <a href="http://en.wikipedia.org/wiki/Peer-to-peer">Peer-to-peer</a>
 * 
 * @author william.liangf
 */
@SPI
public interface Networker {

    /**
     * lookup group.
     * 
     * @param url group url
     * @return group.
     */
    Group lookup(URL url) throws RemotingException;

}