将异常从CXF侦听器传播到异常映射器

Question

我有一个流程，在CXF客户机上，我在拦截器、提供者和异常映射器中有JAXR。在我的例子中，我通过截取程序捕捉到来自客户端的错误响应，然后我想中止cxf总线链并抛出一个错误。不幸的是，我无法做到这一点，因为在任何情况下，拦截器抛出的异常都只会被记录，但主要错误（错误的json格式）会传播到异常映射器。我想避免使用异常映射器，但我不知道如何避免。我使用WebClient实现如下拦截器：

@Component
public class MyInterceptor extends AbstractPhaseInterceptor<Message> {

    public MyInterceptor() {
        super(POST_STREAM);
    }

    @Override
    public void handleMessage(Message message) throws Fault {
        if (message != null) {
                //message.getExchange().setOneWay(true);
                //message.getExchange().put(Exception.class, new MyException());
                //message.getInterceptorChain().abort();
                //message.setContent(Exception.class, new MyException());
                //Endpoint ep = message.getExchange().get(Endpoint.class);
                //message.getInterceptorChain().abort();
                //if (ep.getInFaultObserver() != null) {
                //    ep.getInFaultObserver().onMessage(message);
                //}
                //throw new WebApplicationException( new MyException());

                //message.setContent(Response.class, response);
                throw new Fault(new MyException());
            }
        } 

我读到应该实现jaxrs过滤器，因为拦截器抛出的异常不会传播到异常映射器。借助WebClient实现，在java中有没有办法做到这一点？

S client = create(url, clazz, list(jsonProvider(), providers));
WebClient.getConfig(client).getInInterceptors().add(new MyInterceptor());

我也尝试过在拦截器上使用不同的阶段，但也不起作用。

Answer 1

我完全同意前面的回答。我的实现看起来像：

@Component
public class ServiceFailureInterceptor extends AbstractPhaseInterceptor<Message> {

    private static final Logger LOG = LoggerFactory.getLogger(ServiceFailureInterceptor.class);

    public ServiceFailureInterceptor() {
        super(PRE_STREAM);
    }

    @Override
    public void handleMessage(Message message) {
        if (message != null) {
            int responseCode = (int) message.get(Message.RESPONSE_CODE);
                LogicException logicException = ErrorMapper.HTTP_STATUS_CODE_MAPPER.get(responseCode);
                InputStream is = b2stream(MapperUtils.json().toBytes(logicException));

                // clear old message & exchange
                Exchange exchange = message.getExchange();
                for (Class<?> contentFormat : message.getContentFormats()) {
                    message.setContent(contentFormat, null);
                }

                resetOrigInterceptorChain(message);
                resetFault(exchange);

                message.setContent(InputStream.class, is);
                Message outMessage = createOutMessage(exchange, is);
                prepareMessage(outMessage);
                prepareMessage(message);
        }
    }

    private void prepareMessage(Message message) {
        message.put(Message.REQUESTOR_ROLE, true);
        message.put(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON);
    }


    private Message createOutMessage(Exchange exchange, InputStream logicException) {
        Endpoint ep = exchange.get(Endpoint.class);
        Message outMessage = ep != null ? ep.getBinding().createMessage() : new MessageImpl();
        outMessage.setContent(InputStream.class, logicException);
        exchange.setOutMessage(outMessage);
        outMessage.setExchange(exchange);
        return outMessage;
    }

    private void resetFault(Exchange exchange) {
        exchange.put(Exception.class, null);
    }

    private void resetOrigInterceptorChain(Message message) {
        InterceptorChain chain = message.getInterceptorChain();
        if (chain != null) {
            for (Interceptor<?> interceptor : chain) {
                chain.remove(interceptor);
            }
            chain.reset();
        }
    }
}

手动设置此异常后，我将转到ExceptionMapper实现，在该实现中，我的逻辑异常被消耗，异常响应正在构建。当通过WebClient声明为提供者时，我无法避免异常映射器，所以我决定使用它并稍后重新映射异常。

Answer 2

我一直在研究和测试你的问题。问题是，从CXF拦截器抛出的异常逃逸了JAX-RS流（请参阅CXF团队的答案）

从拦截器生成的Fault可以在拦截器本身中实现handleFault

 public void handleFault(Message message) {
       Exception e = message.getContent(Exception.class);
 }

或者实现一个FaultListener并在CXF总线上注册它

WebClient.getConfig(client).getBus().getProperties().put("org.apache.cxf.logging.FaultListener",new MyFaultListener());

public class MyFaultListener implements FaultListener{
    public boolean faultOccurred(final Exception exception,final String description,final Message message) {
        //return false to avoid warning of default CXF logging interceptor
        return false;
    }
}

但您不能从拦截器返回自定义响应，也不能向客户端响应错误。

我发现的实现所需行为的变通方法包括用一个自定义对象替换响应，该对象可以通过您通常的方法调用来处理，比如异常映射器。请参阅CXF/JAX-RS：从拦截器返回自定义响应

进入拦截器。handleMessage检查所需的条件，并创建一个带有自定义状态和实体的响应。之后，停止链条

public class MyInterceptor extends AbstractPhaseInterceptor<Message> {

    public MyInterceptor() {
        super(Phase.POST_STREAM);
    }

    @Override
    public void handleMessage(Message message) throws Fault {
        if (message != null) {
            //check the condition to raise the error 
            //build the custom Response replacing service call
            Response response = Response
                    .status(Response.Status.BAD_REQUEST)
                    .entity("custom error")
                    .build();
            message.getExchange().put(Response.class, response);

            //abort interceptor chain in you want to stop processing or throw a Fault (catched by handleFault)
            //message.getInterceptorChain().abort();
            //throw new Fault (new MyException());

        }

    public void handleFault(Message messageParam) {
    }
}

在创建JAXRS客户端时，将ResponseExceptionMapper添加为提供程序

providers.add(new ResponseExceptionMapper<WebApplicationException>() {

    @Override
    public WebApplicationException fromResponse(Response r) {
        return new WebApplicationException(r);
    }

});

YourService proxy = JAXRSClientFactory.create(url, clazz,providers);
Client client = WebClient.client(proxy);
WebClient.getConfig(client).getInInterceptors().add(new MyInterceptor());

之后，调用proxy。yourService（）如果完成拦截器检查，将引发WebApplicationException。你可以抓住它，也可以用你想要的方式重新抓捕它

try{
    proxy.yourService();
}catch (WebApplicationException e){
}

希望这有帮助