序

zuul的SimpleHostRoutingFilter主要用来转发不走eureka的proxy，里头是使用httpclient来转发请求的，但是有时候我们需要改动相关httpclient的配置，这个时候，就需要修改SimpleHostRoutingFilter了，这里讲一下如何扩展SimpleHostRoutingFilter。

自定义SimpleHostRoutingFilter

比如把httpclient的CookieSpec设置为default，比如把SSLContext升级为TLSv1.2

public class CustomHostRoutingFilter extends SimpleHostRoutingFilter{

    private static final Logger LOGGER = LoggerFactory.getLogger(CustomHostRoutingFilter.class);

    @Value("${zuul.host.socket-timeout-millis}")
    int SOCKET_TIMEOUT;

    @Value("${zuul.host.connect-timeout-millis}")
    int CONNECTION_TIMEOUT;

    private ZuulProperties.Host hostProperties;

    private boolean sslHostnameValidationEnabled;

    private PoolingHttpClientConnectionManager connectionManager;

    public CustomHostRoutingFilter(ProxyRequestHelper helper, ZuulProperties properties) {
        super(helper, properties);
        this.sslHostnameValidationEnabled = properties.isSslHostnameValidationEnabled();
        this.hostProperties = properties.getHost();
        LOGGER.error("CustomHostRoutingFilter init");
    }

    @Override
    protected CloseableHttpClient newClient() {
        final RequestConfig requestConfig = RequestConfig.custom()
                .setSocketTimeout(SOCKET_TIMEOUT)
                .setConnectTimeout(CONNECTION_TIMEOUT)
                // 这里改为default
                .setCookieSpec(CookieSpecs.DEFAULT).build();

        HttpClientBuilder httpClientBuilder = HttpClients.custom();
        if (!this.sslHostnameValidationEnabled) {
            httpClientBuilder.setSSLHostnameVerifier(NoopHostnameVerifier.INSTANCE);
        }
        return httpClientBuilder.setConnectionManager(newConnectionManager())
                .disableContentCompression()
                .useSystemProperties().setDefaultRequestConfig(requestConfig)
                .setRetryHandler(new DefaultHttpRequestRetryHandler(0, false))
                .setRedirectStrategy(new RedirectStrategy() {
                    @Override
                    public boolean isRedirected(HttpRequest request,
                                                HttpResponse response, HttpContext context)
                            throws ProtocolException {
                        return false;
                    }

                    @Override
                    public HttpUriRequest getRedirect(HttpRequest request,
                                                      HttpResponse response, HttpContext context)
                            throws ProtocolException {
                        return null;
                    }
                }).build();
    }

    @Override
    protected PoolingHttpClientConnectionManager newConnectionManager() {
        try {
            // 这里改为TLS
            final SSLContext sslContext = SSLContext.getInstance("TLSv1.2");
            sslContext.init(null, new TrustManager[] { new X509TrustManager() {
                @Override
                public void checkClientTrusted(X509Certificate[] x509Certificates,
                                               String s) throws CertificateException {
                }

                @Override
                public void checkServerTrusted(X509Certificate[] x509Certificates,
                                               String s) throws CertificateException {
                }

                @Override
                public X509Certificate[] getAcceptedIssuers() {
                    return null;
                }
            } }, new SecureRandom());

            RegistryBuilder<ConnectionSocketFactory> registryBuilder = RegistryBuilder
                    .<ConnectionSocketFactory> create()
                    .register(HTTP_SCHEME, PlainConnectionSocketFactory.INSTANCE);
            if (this.sslHostnameValidationEnabled) {
                registryBuilder.register(HTTPS_SCHEME,
                        new SSLConnectionSocketFactory(sslContext));
            }
            else {
                registryBuilder.register(HTTPS_SCHEME, new SSLConnectionSocketFactory(
                        sslContext, NoopHostnameVerifier.INSTANCE));
            }
            final Registry<ConnectionSocketFactory> registry = registryBuilder.build();

            this.connectionManager = new PoolingHttpClientConnectionManager(registry, null, null, null,
                    hostProperties.getTimeToLive(), hostProperties.getTimeUnit());
            this.connectionManager
                    .setMaxTotal(this.hostProperties.getMaxTotalConnections());
            this.connectionManager.setDefaultMaxPerRoute(
                    this.hostProperties.getMaxPerRouteConnections());
            return this.connectionManager;
        }
        catch (Exception ex) {
            throw new RuntimeException(ex);
        }
    }
}

配置自定义的filter

@Configuration
@EnableZuulProxy
public class CustomZuulProxyConfig extends ZuulProxyConfiguration{

    @Bean
    @Override
    public SimpleHostRoutingFilter simpleHostRoutingFilter(ProxyRequestHelper helper,
                                                           ZuulProperties zuulProperties) {
        return new CustomHostRoutingFilter(helper, zuulProperties);
    }
}

这样就大功告成了

doc

• CustomHostRoutingFilterTests