Fixed content length handling issues. (#2894) (#2920)

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/route/SimpleHostRoutingFilter.java

@@ -35,6 +35,7 @@ import org.apache.http.Header;
 import org.apache.http.HttpHost;
 import org.apache.http.HttpRequest;
 import org.apache.http.HttpResponse;
+import org.apache.http.client.HttpClient;
 import org.apache.http.client.config.CookieSpecs;
 import org.apache.http.client.config.RequestConfig;
 import org.apache.http.client.methods.CloseableHttpResponse;
@@ -56,6 +57,7 @@ import org.springframework.cloud.netflix.zuul.filters.ZuulProperties;
 import org.springframework.cloud.netflix.zuul.filters.ZuulProperties.Host;
 import org.springframework.cloud.netflix.zuul.util.ZuulRuntimeException;
 import org.springframework.context.event.EventListener;
+import org.springframework.http.HttpHeaders;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 import org.springframework.util.StringUtils;
@@ -91,6 +93,7 @@ public class SimpleHostRoutingFilter extends ZuulFilter {
 	private HttpClientConnectionManager connectionManager;
 	private CloseableHttpClient httpClient;
 	private boolean customHttpClient = false;
+	private boolean useServlet31 = true;
 
 	@EventListener
 	public void onPropertyChange(EnvironmentChangeEvent event) {
@@ -125,6 +128,7 @@ public class SimpleHostRoutingFilter extends ZuulFilter {
 				.isForceOriginalQueryStringEncoding();
 		this.connectionManagerFactory = connectionManagerFactory;
 		this.httpClientFactory = httpClientFactory;
+		checkServletVersion();
 	}
 
 	public SimpleHostRoutingFilter(ProxyRequestHelper helper, ZuulProperties properties,
@@ -136,6 +140,7 @@ public class SimpleHostRoutingFilter extends ZuulFilter {
 				.isForceOriginalQueryStringEncoding();
 		this.httpClient = httpClient;
 		this.customHttpClient = true;
+		checkServletVersion();
 	}
 
 	@PostConstruct
@@ -191,7 +196,7 @@ public class SimpleHostRoutingFilter extends ZuulFilter {
 				.buildZuulRequestQueryParams(request);
 		String verb = getVerb(request);
 		InputStream requestEntity = getRequestBody(request);
-		if (request.getContentLength() < 0) {
+		if (getContentLength(request) < 0) {
 			context.setChunkedRequestBody();
 		}
 
@@ -209,6 +214,21 @@ public class SimpleHostRoutingFilter extends ZuulFilter {
 		return null;
 	}
 
+	protected void checkServletVersion() {
+		// To support Servlet API 3.1 we need to check if getContentLengthLong exists
+		// Spring 5 minimum support is 3.0, so this stays
+		try {
+			HttpServletRequest.class.getMethod("getContentLengthLong");
+			useServlet31 = true;
+		} catch(NoSuchMethodException e) {
+			useServlet31 = false;
+		}
+	}
+
+	protected void setUseServlet31(boolean useServlet31) {
+		this.useServlet31 = useServlet31;
+	}
+
 	protected HttpClientConnectionManager getConnectionManager() {
 		return connectionManager;
 	}
@@ -232,7 +252,7 @@ public class SimpleHostRoutingFilter extends ZuulFilter {
 		URL host = RequestContext.getCurrentContext().getRouteHost();
 		HttpHost httpHost = getHttpHost(host);
 		uri = StringUtils.cleanPath((host.getPath() + uri).replaceAll("/{2,}", "/"));
-		int contentLength = request.getContentLength();
+		long contentLength = getContentLength(request);
 
 		ContentType contentType = null;
 
@@ -376,4 +396,19 @@ public class SimpleHostRoutingFilter extends ZuulFilter {
 	boolean isSslHostnameValidationEnabled() {
 		return this.sslHostnameValidationEnabled;
 	}
-}
+
+	// Get the header value as a long in order to more correctly proxy very large requests
+	protected long getContentLength(HttpServletRequest request) {
+		if(useServlet31){
+			return request.getContentLengthLong();
+		}
+		String contentLengthHeader = request.getHeader(HttpHeaders.CONTENT_LENGTH);
+		if (contentLengthHeader != null) {
+			try {
+				return Long.parseLong(contentLengthHeader);
+			}
+			catch (NumberFormatException e){}
+		}
+		return request.getContentLength();
+	}
+}
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