Reference Listener Extension

<!-- Reference service listener -->
<dubbo:reference listener="xxx,yyy" />
<!-- Reference service default listener -->
<dubbo:consumer listener="xxx,yyy" />

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