直接上代码，服务提供方

package com.weifor.xx.api.dubbo;

import com.weifor.util.WeiFor;
import lombok.extern.slf4j.Slf4j;
import org.apache.dubbo.common.constants.CommonConstants;
import org.apache.dubbo.common.extension.Activate;
import org.apache.dubbo.rpc.*;

import java.util.concurrent.CompletableFuture;

/**
 *
 * Dubbo过滤器，执行者
 *
 * Copyright http://www.weifor.com/
 * Author PangShuqiang
 * Blog https://blog.csdn.net/PangSir
 * Email pangshuqiang@163.com
 * QQ 127015919
 * Date: 2021/6/25
 */ 
@Slf4j
@Activate(group = CommonConstants.PROVIDER)
public class DubboProviderFilter implements Filter {
    @Override
    public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
        String appName = RpcContext.getContext().getAttachment(WebConstEnum.Model.SERVER_NAME);
        String currentPath = invoker.getUrl().getPath().concat("." + invocation.getMethodName());
        log.info("调用Dubbo服务，项目名称：{}", appName);
        if (true) {
            RpcContext.getContext().getAttachment("appName");
            return invoker.invoke(invocation);
        } else {
            log.error("调用Dubbo服务失败！Path：".concat(currentPath));
            CompletableFuture b = new CompletableFuture ();
            AsyncRpcResult asyncRpcResult = new AsyncRpcResult(b,invocation);
            asyncRpcResult.setValue("Provider 服务失败，Dubbo Provider 停止执行！Path：" + currentPath);
            return asyncRpcResult;
        }
    }
}

package com.weifor.xx.api.dubbo;

import lombok.extern.slf4j.Slf4j;
import org.apache.dubbo.common.constants.CommonConstants;
import org.apache.dubbo.common.extension.Activate;
import org.apache.dubbo.rpc.*;

import java.util.Arrays;
import java.util.Map;
import java.util.concurrent.CompletableFuture;

/**
 *
 * Dubbo过滤器，调用者
 *
 * Copyright http://www.weifor.com/
 * Author PangShuqiang
 * Blog https://blog.csdn.net/PangSir
 * Email pangshuqiang@163.com
 * QQ 127015919
 * Date: 2021/6/25
 */
@Slf4j
@Activate(group = CommonConstants.CONSUMER)
public class DubboConsumerFilter implements Filter {
    @Override
    public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
        // Result result = invoker.invoke(invocation);
        if (invoker.getUrl() == null) {
            log.error("调用Dubbo服务时，准备动作处理失败！");
            throw new RpcException("调用Dubbo服务时，准备动作处理失败！");
        }
        Class<?> serviceType = invoker.getInterface();
        Map attachments = invocation.getAttachments();
        log.info("[{}], [{}], [{}]", invoker.getInterface(), invocation.getMethodName(), Arrays.toString(invocation.getArguments()));

        String currentPath = invoker.getUrl().getPath().concat("." + invocation.getMethodName());
        if (true) {
            RpcContext.getContext().setAttachment("appName", "这个是你给我的！");

            return invoker.invoke(invocation);
        } else {
            log.error("调用Dubbo服务时失败！Path：".concat(currentPath));

            CompletableFuture b = new CompletableFuture ();
            AsyncRpcResult asyncRpcResult = new AsyncRpcResult(b,invocation);
            asyncRpcResult.setValue("Consumer 服务失败，Dubbo Consumer 停止调用！Path：" + currentPath);
            return asyncRpcResult;
        }
    }
}

关键配置，官方说明：https://dubbo.apache.org/docs/v2.7/dev/impls/filter/#m-docsv27devimplsfilter

无论是SpringCloud还是SpringBoot，均可按照Spring方式进行配置，具体可在项目Resource下执行：

1、建文件夹及文件：META-INF/dubbo/org.apache.dubbo.rpc.Filter，其中META-INF/dubbo是文件夹，org.apache.dubbo.rpc.Filter是整个文件名。

2、在org.apache.dubbo.rpc.Filter加入自定义类：

dubboConsumerFilter=com.weifor.xx.api.dubbo.DubboConsumerFilter
dubboProviderFilter=com.weifor.xx.api.dubbo.DubboProviderFilter

3、在配置文件application.yml、bootstrap.yml或application.property里加入：

dubbo:
  scan:
    base-packages: com.weifor
  consumer:
    check: false #作为消费者时启动不检查
    #generic: false #是否缺省泛化接口，默认false
    #timeout: 3000
    #retries: 0
    filter: dubboConsumerFilter
  provider:
    #timeout: 3000
    #retries: 0
    filter: dubboProviderFilter
  #cloud:
    #subscribed-services: xxx

为什么设计得这么啰嗦，实现自定义过滤器后，还要增加org.apache.dubbo.rpc.Filter

 加了文件定义文件还没得，还要配置dubbo.consumer.filter和dubbo.provider.filter

吐槽一下：Apache Dubbo 你能不能设计得更啰嗦点？就不能直接扫描找到项目里的自定义FIlter文件？？然后，就没有然后了，这么简单的事还要搞配置。。。。。。