dubbo调用中provider返回RuntimeException

电玩女神 2021-12-12 13:07 231阅读 0赞

现在写代码的，都用分布式的，那么最常用的就是dubbo了，但是，今天在使用dubbo的时候遇到了一个问题。  
就是provider提供的接口中有异常验证，但是，在验证失败的时候，provider给返回了一个RuntimeException，这样导致我不能获取到对应的异常信息。  
出了这样的问题，先debug，跟进去，在dubbo的ExceptionFilter中找到了

public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
            try {
                Result result = invoker.invoke(invocation);
                if (result.hasException() && GenericService.class != invoker.getInterface()) {
                    try {
                        Throwable exception = result.getException();
    
                        // directly throw if it's checked exception
                        if (!(exception instanceof RuntimeException) && (exception instanceof Exception)) {
                            return result;
                        }
                        // directly throw if the exception appears in the signature
                        try {
                            Method method = invoker.getInterface().getMethod(invocation.getMethodName(), invocation.getParameterTypes());
                            Class<?>[] exceptionClassses = method.getExceptionTypes();
                            for (Class<?> exceptionClass : exceptionClassses) {
                                if (exception.getClass().equals(exceptionClass)) {
                                    return result;
                                }
                            }
                        } catch (NoSuchMethodException e) {
                            return result;
                        }
    
                        // for the exception not found in method's signature, print ERROR message in server's log.
                        logger.error("Got unchecked and undeclared exception which called by " + RpcContext.getContext().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 result;
                        }
                        // directly throw if it's JDK exception
                        String className = exception.getClass().getName();
                        if (className.startsWith("java.") || className.startsWith("javax.")) {
                            return result;
                        }
                        // directly throw if it's dubbo exception
                        if (exception instanceof RpcException) {
                            return result;
                        }
    
                        // otherwise, wrap with RuntimeException and throw back to the client
                        return new RpcResult(new RuntimeException(StringUtils.toString(exception)));
                    } catch (Throwable e) {
                        logger.warn("Fail to ExceptionFilter when called by " + RpcContext.getContext().getRemoteHost()
                                + ". service: " + invoker.getInterface().getName() + ", method: " + invocation.getMethodName()
                                + ", exception: " + e.getClass().getName() + ": " + e.getMessage(), e);
                        return result;
                    }
                }
                return result;
            } catch (RuntimeException e) {
                logger.error("Got unchecked and undeclared exception which called by " + RpcContext.getContext().getRemoteHost()
                        + ". service: " + invoker.getInterface().getName() + ", method: " + invocation.getMethodName()
                        + ", exception: " + e.getClass().getName() + ": " + e.getMessage(), e);
                throw e;
            }
        }

通过上面的代码，能推断出不是consumer的问题，应给是provider在返回结果序列化的时候，没有获取到指定的以异常类，于是，联系类provider，让他们去处理了