十、微服务网关之Zuul容错与回退

Spring Cloud中，Zuul默认已经整合了Hystrix。

Zuul回退

编写Zuul回退类:

@Component
public class MyFallbackProvider implements FallbackProvider {
//    表明是为哪个微服务提供回退，*代表所有
    @Override
    public String getRoute() {
        return "*";
    }

    @Override
    public ClientHttpResponse fallbackResponse() {
        return this.response(HttpStatus.INTERNAL_SERVER_ERROR);
    }

    @Override
    public ClientHttpResponse fallbackResponse(Throwable cause) {
        if (cause instanceof HystrixTimeoutException) {
            return response(HttpStatus.GATEWAY_TIMEOUT);
        } else {
            return this.fallbackResponse();
        }
    }

    private ClientHttpResponse response(final HttpStatus status) {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return status;
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return status.value();
            }

            @Override
            public String getStatusText() throws IOException {
                return status.getReasonPhrase();
            }

            @Override
            public void close() {

            }

            @Override
            public InputStream getBody() throws IOException {
                return new ByteArrayInputStream("服务不可用，请稍后再试。".getBytes());
            }

            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders httpHeaders = new HttpHeaders();
                MediaType mediaType = new MediaType("application", "json", Charset.forName("UTF-8"));
                httpHeaders.setContentType(mediaType);
                return httpHeaders;
            }
        };
    }
}

当访问的微服务无法正常响应时，会返回如下内容:

服务不可用，请稍后再试。

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该文章摘自《Spring Cloud 与 Docker 微服务架构实战(第二版)》

以上