Source:
public HttpClient createHttpClient(FilterConfig filterConfig) { HttpClientBuilder builder; GatewayConfig gatewayConfig = (GatewayConfig) filterConfig.getServletContext().getAttribute(GatewayConfig.GATEWAY_CONFIG_ATTRIBUTE); GatewayServices services = (GatewayServices) filterConfig.getServletContext() .getAttribute(GatewayServices.GATEWAY_SERVICES_ATTRIBUTE); if (gatewayConfig != null && gatewayConfig.isMetricsEnabled()) { MetricsService metricsService = services.getService(GatewayServices.METRICS_SERVICE); builder = metricsService.getInstrumented(HttpClientBuilder.class); } else { builder = HttpClients.custom(); } boolean useTwoWaySsl = Boolean.parseBoolean(filterConfig.getInitParameter("useTwoWaySsl")); SSLContext sslContext = createSSLContext(services, useTwoWaySsl); if(sslContext != null) { builder.setSSLSocketFactory(new SSLConnectionSocketFactory(sslContext)); } if (Boolean.parseBoolean(System.getProperty(GatewayConfig.HADOOP_KERBEROS_SECURED))) { CredentialsProvider credentialsProvider = new BasicCredentialsProvider(); credentialsProvider.setCredentials(AuthScope.ANY, new UseJaasCredentials()); Registry<AuthSchemeProvider> authSchemeRegistry = RegistryBuilder.<AuthSchemeProvider>create() .register(AuthSchemes.SPNEGO, new KnoxSpnegoAuthSchemeFactory(true)) .build(); builder.setDefaultAuthSchemeRegistry(authSchemeRegistry) .setDefaultCookieStore(new HadoopAuthCookieStore(gatewayConfig)) .setDefaultCredentialsProvider(credentialsProvider); } else { builder.setDefaultCookieStore(new NoCookieStore()); } builder.setKeepAliveStrategy( DefaultConnectionKeepAliveStrategy.INSTANCE ); builder.setConnectionReuseStrategy( DefaultConnectionReuseStrategy.INSTANCE ); builder.setRedirectStrategy( new NeverRedirectStrategy() ); builder.setRetryHandler( new NeverRetryHandler() ); int maxConnections = getMaxConnections( filterConfig ); builder.setMaxConnTotal( maxConnections ); builder.setMaxConnPerRoute( maxConnections ); builder.setDefaultRequestConfig( getRequestConfig( filterConfig ) ); builder.disableContentCompression(); return builder.build(); }

Target:
public HttpClient createHttpClient(FilterConfig filterConfig) { HttpClientBuilder builder; GatewayConfig gatewayConfig = (GatewayConfig) filterConfig.getServletContext().getAttribute(GatewayConfig.GATEWAY_CONFIG_ATTRIBUTE); GatewayServices services = (GatewayServices) filterConfig.getServletContext() .getAttribute(GatewayServices.GATEWAY_SERVICES_ATTRIBUTE); if (gatewayConfig != null && gatewayConfig.isMetricsEnabled()) { MetricsService metricsService = services.getService(GatewayServices.METRICS_SERVICE); builder = metricsService.getInstrumented(HttpClientBuilder.class); } else { builder = HttpClients.custom(); } SSLContext sslContext = createSSLContext(services, filterConfig); if(sslContext != null) { builder.setSSLSocketFactory(new SSLConnectionSocketFactory(sslContext)); } if (Boolean.parseBoolean(System.getProperty(GatewayConfig.HADOOP_KERBEROS_SECURED))) { CredentialsProvider credentialsProvider = new BasicCredentialsProvider(); credentialsProvider.setCredentials(AuthScope.ANY, new UseJaasCredentials()); Registry<AuthSchemeProvider> authSchemeRegistry = RegistryBuilder.<AuthSchemeProvider>create() .register(AuthSchemes.SPNEGO, new KnoxSpnegoAuthSchemeFactory(true)) .build(); builder.setDefaultAuthSchemeRegistry(authSchemeRegistry) .setDefaultCookieStore(new HadoopAuthCookieStore(gatewayConfig)) .setDefaultCredentialsProvider(credentialsProvider); } else { builder.setDefaultCookieStore(new NoCookieStore()); } builder.setKeepAliveStrategy( DefaultConnectionKeepAliveStrategy.INSTANCE ); builder.setConnectionReuseStrategy( DefaultConnectionReuseStrategy.INSTANCE ); builder.setRedirectStrategy( new NeverRedirectStrategy() ); builder.setRetryHandler( new NeverRetryHandler() ); int maxConnections = getMaxConnections( filterConfig ); builder.setMaxConnTotal( maxConnections ); builder.setMaxConnPerRoute( maxConnections ); builder.setDefaultRequestConfig( getRequestConfig( filterConfig ) ); builder.disableContentCompression(); return builder.build(); }