1. 扩展说明

基于传输层之上，实现Request-Response信息交换语义。

2. 扩展接口

• com.alibaba.dubbo.remoting.exchange.Exchanger
• com.alibaba.dubbo.remoting.exchange.ExchangeServer
• com.alibaba.dubbo.remoting.exchange.ExchangeClient

3. 扩展配置

<dubbo:protocol exchanger="xxx" />
<dubbo:provider exchanger="xxx" /> <!-- 缺省值设置，当<dubbo:protocol>没有配置exchanger属性时，使用此配置 -->

4. 已知扩展

com.alibaba.dubbo.remoting.exchange.exchanger.HeaderExchanger

5. 扩展示例

Maven项目结构

src
 |-main
    |-java
        |-com
            |-xxx
                |-XxxExchanger.java (实现Exchanger接口)
                |-XxxExchangeServer.java (实现ExchangeServer接口)
                |-XxxExchangeClient.java (实现ExchangeClient接口)
    |-resources
        |-META-INF
            |-dubbo
                |-com.alibaba.dubbo.remoting.exchange.Exchanger (纯文本文件，内容为：xxx=com.xxx.XxxExchanger)

XxxExchanger.java

package com.xxx;
 
import com.alibaba.dubbo.remoting.exchange.Exchanger;
 
 
public class XxxExchanger implements Exchanger {
    public ExchangeServer bind(URL url, ExchangeHandler handler) throws RemotingException {
        return new XxxExchangeServer(url, handler);
    }
    public ExchangeClient connect(URL url, ExchangeHandler handler) throws RemotingException {
        return new XxxExchangeClient(url, handler);
    }
}

XxxExchangeServer.java

package com.xxx;
 
import com.alibaba.dubbo.remoting.exchange.ExchangeServer;
 
public class XxxExchangeServer impelements ExchangeServer {
    // ...
}

XxxExchangeClient.java

package com.xxx;
 
import com.alibaba.dubbo.remoting.exchange.ExchangeClient;
 
public class XxxExchangeClient impelments ExchangeClient {
    // ...
}

META-INF/dubbo/com.alibaba.dubbo.remoting.exchange.Exchanger

xxx=com.xxx.XxxExchanger