dubbo-java 3.2 beta 服务端全局异常处理filter 无法按预期执行

目的:

在provider端 使用filter 拦截provider 处理过程的异常； 在业务代码中抛出异常后，没有按预期执行 filter 中onResponse 方法，而是执行了onError 方法，在onError 方法中，又无法对结果或异常信息进行包装改写；

问题项目示例地址：https://github.com/gebizhuxiaowang/dubbo-demo 使用postMan调用gRPC 接口：helloException 可复现；

求助：

在服务端拦截全局异常的方法是否正确？ 若正确，上述例子中为什么无法预期执行对应的方法？ filter 代码如下：

package com.example.dubbo.filter;

import org.apache.dubbo.common.constants.CommonConstants; import org.apache.dubbo.common.extension.Activate; import org.apache.dubbo.common.logger.Logger; import org.apache.dubbo.common.logger.LoggerFactory; import org.apache.dubbo.common.utils.ReflectUtils; import org.apache.dubbo.common.utils.StringUtils; import org.apache.dubbo.rpc.Filter; import org.apache.dubbo.rpc.Invocation; import org.apache.dubbo.rpc.Invoker; import org.apache.dubbo.rpc.Result; import org.apache.dubbo.rpc.RpcContext; import org.apache.dubbo.rpc.RpcException; import org.apache.dubbo.rpc.service.GenericService;

import java.lang.reflect.Method;

/** * @version 1.0 * @classname DubboProviderExceptionFilter * @description todo */ @Activate(group = CommonConstants.PROVIDER) public class DubboProviderExceptionFilter implements Filter, Filter.Listener {

private static Logger log = LoggerFactory.getLogger(DubboProviderExceptionFilter.class);

@Override
public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    // return invoker.invoke(invocation);
    Result appResponse = invoker.invoke(invocation);
    if (appResponse.hasException() && GenericService.class != invoker.getInterface()) {
        try {
            Throwable e = appResponse.getException();
            log.error(" [MAGICAL-DUBBO] Fail to MagicalDubboRpcExceptionFilter when called by " + RpcContext.getContext().getRemoteHost() + ". service: " + invoker.getInterface().getName() + ", method: " + invocation.getMethodName() + ", exception: " + e.getClass().getName() + ": " + e.getMessage(), e);
        } catch (Throwable e) {
            log.error(" [MAGICAL-DUBBO] Fail to MagicalDubboRpcExceptionFilter when called by " + RpcContext.getContext().getRemoteHost() + ". service: " + invoker.getInterface().getName() + ", method: " + invocation.getMethodName() + ", exception: " + e.getClass().getName() + ": " + e.getMessage(), e);
            // return AsyncRpcResult.newDefaultAsyncResult(R.fail(65510, "远程服务调用发生异常"), invocation);
        }
    }
    return appResponse;
}

// 业务代码抛异常后，不会进入这个方法
@Override
public void onResponse(Result appResponse, Invoker<?> invoker, Invocation invocation) {
    if (appResponse.hasException() && GenericService.class != invoker.getInterface()) {
        try {
            Throwable exception = appResponse.getException();

            // directly throw if it's checked exception
            if (!(exception instanceof RuntimeException) && (exception instanceof Exception)) {
                return;
            }
            // directly throw if the exception appears in the signature
            try {
                Method method = invoker.getInterface().getMethod(invocation.getMethodName(),
                        invocation.getParameterTypes());
                Class<?>[] exceptionClasses = method.getExceptionTypes();
                for (Class<?> exceptionClass : exceptionClasses) {
                    if (exception.getClass().equals(exceptionClass)) {
                        return;
                    }
                }
            } catch (NoSuchMethodException e) {
                return;
            }


            // for the exception not found in method's signature, print ERROR message in server's log.
            log.error("Got unchecked and undeclared exception which called by " + RpcContext.getServiceContext().getRemoteHost() + ". service: " + invoker.getInterface().getName() + ", method: " + invocation.getMethodName() + ", exception: " + exception.getClass().getName() + ": " + exception.getMessage(), exception);

            // directly throw if exception class and interface class are in the same jar file.
            String serviceFile = ReflectUtils.getCodeBase(invoker.getInterface());
            String exceptionFile = ReflectUtils.getCodeBase(exception.getClass());
            if (serviceFile == null || exceptionFile == null || serviceFile.equals(exceptionFile)) {
                return;
            }
            // directly throw if it's JDK exception
            String className = exception.getClass().getName();
            if (className.startsWith("java.") || className.startsWith("javax.")) {
                return;
            }

            // directly throw if it's dubbo exception
            if (exception instanceof RpcException) {
                return;
            }

            // otherwise, wrap with RuntimeException and throw back to the client
            appResponse.setException(new RuntimeException(StringUtils.toString(exception)));
        } catch (Throwable e) {
            log.warn("Fail to ExceptionFilter when called by " + RpcContext.getServiceContext().getRemoteHost() + ". service: " + invoker.getInterface().getName() + ", method: " + invocation.getMethodName() + ", exception: " + e.getClass().getName() + ": " + e.getMessage(), e);
        }
    }
}

@Override
public void onError(Throwable t, Invoker<?> invoker, Invocation invocation) {
    log.error("Got unchecked and undeclared exception which called by " + RpcContext.getServiceContext().getRemoteHost() + ". service: " + invoker.getInterface().getName() + ", method: " + invocation.getMethodName() + ", exception: " + t.getClass().getName() + ": " + t.getMessage(), t);

}

}

业务处理类抛出的异常是自定义异常；

原提问者GitHub用户gebizhuxiaowang