Add fromHttpRequest to UriComponentsBuilder

Before this change, detection of X-Forwarded-* headers was only built
into ServletUriComponentsBuilder.

This change adds a new method for creating a UriComponentsBuilder from
an existing HttpRequest. This is equivalent to the fromUri method +
X-Forwarded-* header values.

spring-web/src/main/java/org/springframework/web/util/UriComponentsBuilder.java

 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,6 +24,7 @@ import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import org.springframework.http.HttpRequest;
 import org.springframework.util.Assert;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
@@ -263,6 +264,55 @@ public class UriComponentsBuilder implements Cloneable {
 		}
 	}
 
+	/**
+	 * Create a new {@code UriComponents} object from the URI associated with
+	 * the given HttpRequest while also overlaying with values from the headers
+	 * "X-Forwarded-Host", "X-Forwarded-Port", and "X-Forwarded-Proto" if present.
+	 *
+	 * @param request the source request
+	 * @return the URI components of the UR
+	 */
+	public static UriComponentsBuilder fromHttpRequest(HttpRequest request) {
+		URI uri = request.getURI();
+		UriComponentsBuilder builder = UriComponentsBuilder.fromUri(uri);
+
+		String scheme = uri.getScheme();
+		String host = uri.getHost();
+		int port = uri.getPort();
+
+		String hostHeader = request.getHeaders().getFirst("X-Forwarded-Host");
+		if (StringUtils.hasText(hostHeader)) {
+			String[] hosts = StringUtils.commaDelimitedListToStringArray(hostHeader);
+			String hostToUse = hosts[0];
+			if (hostToUse.contains(":")) {
+				String[] hostAndPort = StringUtils.split(hostToUse, ":");
+				host  = hostAndPort[0];
+				port = Integer.parseInt(hostAndPort[1]);
+			}
+			else {
+				host = hostToUse;
+				port = -1;
+			}
+		}
+
+		String portHeader = request.getHeaders().getFirst("X-Forwarded-Port");
+		if (StringUtils.hasText(portHeader)) {
+			port = Integer.parseInt(portHeader);
+		}
+
+		String protocolHeader = request.getHeaders().getFirst("X-Forwarded-Proto");
+		if (StringUtils.hasText(protocolHeader)) {
+			scheme = protocolHeader;
+		}
+
+		builder.scheme(scheme);
+		builder.host(host);
+		if (scheme.equals("http") && port != 80 || scheme.equals("https") && port != 443) {
+			builder.port(port);
+		}
+		return builder;
+	}
+
 
 	// build methods
 

spring-web/src/test/java/org/springframework/web/util/UriComponentsBuilderTests.java

 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,11 +31,16 @@ import java.util.HashMap;
 import java.util.Map;
 
 import org.junit.Test;
+
+import org.springframework.http.server.ServletServerHttpRequest;
+import org.springframework.mock.web.test.MockHttpServletRequest;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 import org.springframework.util.StringUtils;
 
 /**
+ * Unit tests for {@link org.springframework.web.util.UriComponentsBuilder}.
+ *
  * @author Arjen Poutsma
  * @author Phillip Webb
  * @author Oliver Gierke
@@ -232,6 +237,25 @@ public class UriComponentsBuilderTests {
 		assertEquals("bar@baz", result.getQueryParams().getFirst("foo"));
 	}
 
+	// Also see X-Forwarded-* related tests in ServletUriComponentsBuilderTests
+
+	@Test
+	public void fromHttpRequest() throws URISyntaxException {
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setScheme("http");
+		request.setServerName("localhost");
+		request.setServerPort(-1);
+		request.setRequestURI("/path");
+		request.setQueryString("a=1");
+
+		UriComponents result = UriComponentsBuilder.fromHttpRequest(new ServletServerHttpRequest(request)).build();
+		assertEquals("http", result.getScheme());
+		assertEquals("localhost", result.getHost());
+		assertEquals(-1, result.getPort());
+		assertEquals("/path", result.getPath());
+		assertEquals("a=1", result.getQuery());
+	}
+
 	@Test
 	public void path() throws URISyntaxException {
 		UriComponentsBuilder builder = UriComponentsBuilder.fromPath("/foo/bar");

spring-webmvc/src/main/java/org/springframework/web/servlet/support/ServletUriComponentsBuilder.java

 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,11 +18,14 @@ package org.springframework.web.servlet.support;
 
 import javax.servlet.http.HttpServletRequest;
 
+import org.springframework.http.HttpRequest;
+import org.springframework.http.server.ServletServerHttpRequest;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 import org.springframework.web.context.request.RequestAttributes;
 import org.springframework.web.context.request.RequestContextHolder;
 import org.springframework.web.context.request.ServletRequestAttributes;
+import org.springframework.web.util.UriComponents;
 import org.springframework.web.util.UriComponentsBuilder;
 import org.springframework.web.util.UrlPathHelper;
 import org.springframework.web.util.WebUtils;
@@ -112,34 +115,11 @@ public class ServletUriComponentsBuilder extends UriComponentsBuilder {
 	 * Initialize a builder with a scheme, host,and port (but not path and query).
 	 */
 	private static ServletUriComponentsBuilder initFromRequest(HttpServletRequest request) {
-		String scheme = request.getScheme();
-		String host = request.getServerName();
-		int port = request.getServerPort();
-
-		String hostHeader = request.getHeader("X-Forwarded-Host");
-		if (StringUtils.hasText(hostHeader)) {
-			String[] hosts = StringUtils.commaDelimitedListToStringArray(hostHeader);
-			String hostToUse = hosts[0];
-			if (hostToUse.contains(":")) {
-				String[] hostAndPort = StringUtils.split(hostToUse, ":");
-				host  = hostAndPort[0];
-				port = Integer.parseInt(hostAndPort[1]);
-			}
-			else {
-				host = hostToUse;
-				port = -1;
-			}
-		}
-
-		String portHeader = request.getHeader("X-Forwarded-Port");
-		if (StringUtils.hasText(portHeader)) {
-			port = Integer.parseInt(portHeader);
-		}
-
-		String protocolHeader = request.getHeader("X-Forwarded-Proto");
-		if (StringUtils.hasText(protocolHeader)) {
-			scheme = protocolHeader;
-		}
+		HttpRequest httpRequest = new ServletServerHttpRequest(request);
+		UriComponents uriComponents = UriComponentsBuilder.fromHttpRequest(httpRequest).build();
+		String scheme = uriComponents.getScheme();
+		String host = uriComponents.getHost();
+		int port = uriComponents.getPort();
 
 		ServletUriComponentsBuilder builder = new ServletUriComponentsBuilder();
 		builder.scheme(scheme);

spring-webmvc/src/test/java/org/springframework/web/servlet/support/ServletUriComponentsBuilderTests.java

@@ -41,7 +41,7 @@ public class ServletUriComponentsBuilderTests {
 		this.request = new MockHttpServletRequest();
 		this.request.setScheme("http");
 		this.request.setServerName("localhost");
-		this.request.setServerPort(80);
+		this.request.setServerPort(-1);
 		this.request.setContextPath("/mvc-showcase");
 	}