Invoker Listener Extension

<!-- Reference Service Listener -->
<dubbo:reference listener="xxx,yyy" /> 
<!-- Default Listener for Reference Services -->
<dubbo:consumer listener="xxx,yyy" /> 

src
 |-main
    |-java
        |-com
            |-xxx
                |-XxxInvokerListener.java (implements InvokerListener interface)
    |-resources
        |-META-INF
            |-dubbo
                |-org.apache.dubbo.rpc.InvokerListener (text file containing: xxx=com.xxx.XxxInvokerListener)

package com.xxx;
 
import org.apache.dubbo.rpc.InvokerListener;
import org.apache.dubbo.rpc.Invoker;
import org.apache.dubbo.rpc.RpcException;
 
public class XxxInvokerListener implements InvokerListener {
    public void referred(Invoker<?> invoker) throws RpcException {
        // ...
    }
    public void destroyed(Invoker<?> invoker) throws RpcException {
        // ...
    }
}

xxx=com.xxx.XxxInvokerListener