9.19. 信息交换扩展

• org.apache.dubbo.remoting.exchange.Exchanger
• org.apache.dubbo.remoting.exchange.ExchangeServer
• org.apache.dubbo.remoting.exchange.ExchangeClient

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

• 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
                  |-org.apache.dubbo.remoting.exchange.Exchanger (纯文本文件，内容为：xxx=com.xxx.XxxExchanger)
  

• XxxExchanger.java：

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

• XxxExchangeClient.java：

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

• META-INF/dubbo/org.apache.dubbo.remoting.exchange.Exchanger：

  xxx=com.xxx.XxxExchanger