自定义 Zuul 异常

java microservices spring-boot spring-cloud netflix-zuul

2022-09-01 20:07:55

我在Zuul中有一个场景，其中URL也被路由的服务可能已关闭。因此，在 JSON 正文响应中，响应正文会抛出 500 HTTP Status 和 ZuulException。

{
  "timestamp": 1459973637928,
  "status": 500,
  "error": "Internal Server Error",
  "exception": "com.netflix.zuul.exception.ZuulException",
  "message": "Forwarding error"
}

我想做的就是自定义或删除JSON响应，并可能更改HTTP状态代码。

我试图创建一个具有@ControllerAdvice异常处理程序，但异常没有被处理程序抓取。

更新：

所以我扩展了Zuul过滤器，我可以看到它在执行错误后进入run方法，然后我如何更改响应。以下是我到目前为止所得到的。我在某处读到了关于SendErrorFilter的信息，但是我如何实现它，它有什么作用？

public class CustomFilter extends ZuulFilter {

    @Override
    public String filterType() {
        return "post";
    }

    @Override
    public int filterOrder() {

        return 1;
    }

    @Override
    public boolean shouldFilter() {
        return true;
    }

    @Override
    public Object run() {
        final RequestContext ctx = RequestContext.getCurrentContext();
        final HttpServletResponse response = ctx.getResponse();
        if (HttpStatus.INTERNAL_SERVER_ERROR.value() == ctx.getResponse().getStatus()) {
            try {
                response.sendError(404, "Error Error"); //trying to change the response will need to throw a JSON body.
            } catch (final IOException e) {
                e.printStackTrace();
            } ;
        }

        return null;
    }

已将其添加到具有@EnableZuulProxy

@Bean
public CustomFilter customFilter() {
    return new CustomFilter();
}

答案 1

我们终于得到了这个工作[由我的一位同事编码]：-

public class CustomErrorFilter extends ZuulFilter {

    private static final Logger LOG = LoggerFactory.getLogger(CustomErrorFilter.class);
    @Override
    public String filterType() {
        return "post";
    }

    @Override
    public int filterOrder() {
        return -1; // Needs to run before SendErrorFilter which has filterOrder == 0
    }

    @Override
    public boolean shouldFilter() {
        // only forward to errorPath if it hasn't been forwarded to already
        return RequestContext.getCurrentContext().containsKey("error.status_code");
    }

    @Override
    public Object run() {
        try {
            RequestContext ctx = RequestContext.getCurrentContext();
            Object e = ctx.get("error.exception");

            if (e != null && e instanceof ZuulException) {
                ZuulException zuulException = (ZuulException)e;
                LOG.error("Zuul failure detected: " + zuulException.getMessage(), zuulException);

                // Remove error code to prevent further error handling in follow up filters
                ctx.remove("error.status_code");

                // Populate context with new response values
                ctx.setResponseBody(“Overriding Zuul Exception Body”);
                ctx.getResponse().setContentType("application/json");
                ctx.setResponseStatusCode(500); //Can set any error code as excepted
            }
        }
        catch (Exception ex) {
            LOG.error("Exception filtering in custom error filter", ex);
            ReflectionUtils.rethrowRuntimeException(ex);
        }
        return null;
    }
}

答案 2

Zuul RequestContext 不包含此答案中提到的内容。
最新的 Zuul 错误筛选器：error.exception

@Component
public class ErrorFilter extends ZuulFilter {
    private static final Logger LOG = LoggerFactory.getLogger(ErrorFilter.class);

    private static final String FILTER_TYPE = "error";
    private static final String THROWABLE_KEY = "throwable";
    private static final int FILTER_ORDER = -1;

    @Override
    public String filterType() {
        return FILTER_TYPE;
    }

    @Override
    public int filterOrder() {
        return FILTER_ORDER;
    }

    @Override
    public boolean shouldFilter() {
        return true;
    }

    @Override
    public Object run() {
        final RequestContext context = RequestContext.getCurrentContext();
        final Object throwable = context.get(THROWABLE_KEY);

        if (throwable instanceof ZuulException) {
            final ZuulException zuulException = (ZuulException) throwable;
            LOG.error("Zuul failure detected: " + zuulException.getMessage());

            // remove error code to prevent further error handling in follow up filters
            context.remove(THROWABLE_KEY);

            // populate context with new response values
            context.setResponseBody("Overriding Zuul Exception Body");
            context.getResponse().setContentType("application/json");
            // can set any error code as excepted
            context.setResponseStatusCode(503);
        }
        return null;
    }
}