/*
 * 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.dubbo.remoting.exchange.support.header;

import org.apache.dubbo.common.URL;
import org.apache.dubbo.remoting.RemotingException;
import org.apache.dubbo.remoting.Transporters;
import org.apache.dubbo.remoting.exchange.ExchangeClient;
import org.apache.dubbo.remoting.exchange.ExchangeHandler;
import org.apache.dubbo.remoting.exchange.ExchangeServer;
import org.apache.dubbo.remoting.exchange.Exchanger;
import org.apache.dubbo.remoting.transport.DecodeHandler;

/**
 * DefaultMessenger
 *
 *
 */
public class HeaderExchanger implements Exchanger {

    public static final String NAME = "header";

    @Override
    public ExchangeClient connect(URL url, ExchangeHandler handler) throws RemotingException {
        // 利用NettyTransporter去connect
        // 为什么在connect和bind时都是DecodeHandler，解码，解的是把InputStream解析成AppResponse对象
        return new HeaderExchangeClient(Transporters.connect(url, new DecodeHandler(new HeaderExchangeHandler(handler))), true);
    }

    @Override
    public ExchangeServer bind(URL url, ExchangeHandler handler) throws RemotingException {

        // 下面会去启动Netty
        // 对handler包装了两层，表示当处理一个请求时，每层Handler负责不同的处理逻辑
        // 为什么在connect和bind时都是DecodeHandler，解码，解的是把InputStream解析成RpcInvocation对象
        return new HeaderExchangeServer(Transporters.bind(url, new DecodeHandler(new HeaderExchangeHandler(handler))));
    }

}
