From 55c4762088cb77db5770c51dc80944f68245f215 Mon Sep 17 00:00:00 2001
From: Markus Malkusch <markus@malkusch.de>
Date: Thu, 16 Jan 2014 04:00:11 +0700
Subject: [PATCH] ServletWebRequest.checkNotModified() methods treat HEAD
 identically to GET request

---
 .../context/request/ServletWebRequest.java    |  9 ++-
 .../request/ServletWebRequestTests.java       | 56 +++++++++++++++++--
 2 files changed, 59 insertions(+), 6 deletions(-)

diff --git a/spring-web/src/main/java/org/springframework/web/context/request/ServletWebRequest.java b/spring-web/src/main/java/org/springframework/web/context/request/ServletWebRequest.java
index 12ef42633913..c6f2ba73a42c 100644
--- a/spring-web/src/main/java/org/springframework/web/context/request/ServletWebRequest.java
+++ b/spring-web/src/main/java/org/springframework/web/context/request/ServletWebRequest.java
@@ -47,6 +47,7 @@ public class ServletWebRequest extends ServletRequestAttributes implements Nativ
 
 	private static final String METHOD_GET = "GET";
 
+	private static final String METHOD_HEAD = "HEAD";
 
 	private HttpServletResponse response;
 
@@ -165,6 +166,10 @@ public boolean isUserInRole(String role) {
 	public boolean isSecure() {
 		return getRequest().isSecure();
 	}
+	
+	private boolean isSafeHttpMethod(String method) {
+		return METHOD_GET.equals(method) || METHOD_HEAD.equals(method);
+	}
 
 	@Override
 	public boolean checkNotModified(long lastModifiedTimestamp) {
@@ -173,7 +178,7 @@ public boolean checkNotModified(long lastModifiedTimestamp) {
 			long ifModifiedSince = getRequest().getDateHeader(HEADER_IF_MODIFIED_SINCE);
 			this.notModified = (ifModifiedSince >= (lastModifiedTimestamp / 1000 * 1000));
 			if (this.response != null) {
-				if (this.notModified && METHOD_GET.equals(getRequest().getMethod())) {
+				if (this.notModified && isSafeHttpMethod(getRequest().getMethod())) {
 					this.response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
 				}
 				else {
@@ -191,7 +196,7 @@ public boolean checkNotModified(String eTag) {
 			String ifNoneMatch = getRequest().getHeader(HEADER_IF_NONE_MATCH);
 			this.notModified = eTag.equals(ifNoneMatch);
 			if (this.response != null) {
-				if (this.notModified && METHOD_GET.equals(getRequest().getMethod())) {
+				if (this.notModified && isSafeHttpMethod(getRequest().getMethod())) {
 					this.response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
 				}
 				else {
diff --git a/spring-web/src/test/java/org/springframework/web/context/request/ServletWebRequestTests.java b/spring-web/src/test/java/org/springframework/web/context/request/ServletWebRequestTests.java
index 18598f31c553..208b8294db28 100644
--- a/spring-web/src/test/java/org/springframework/web/context/request/ServletWebRequestTests.java
+++ b/spring-web/src/test/java/org/springframework/web/context/request/ServletWebRequestTests.java
@@ -116,7 +116,7 @@ public void decoratedNativeRequest() {
 	}
 
 	@Test
-	public void checkNotModifiedTimeStamp() {
+	public void checkNotModifiedTimeStampForGET() {
 		long currentTime = new Date().getTime();
 		servletRequest.setMethod("GET");
 		servletRequest.addHeader("If-Modified-Since", currentTime);
@@ -127,7 +127,7 @@ public void checkNotModifiedTimeStamp() {
 	}
 
 	@Test
-	public void checkModifiedTimeStamp() {
+	public void checkModifiedTimeStampForGET() {
 		long currentTime = new Date().getTime();
 		long oneMinuteAgo  = currentTime - (1000 * 60);
 		servletRequest.setMethod("GET");
@@ -140,7 +140,7 @@ public void checkModifiedTimeStamp() {
 	}
 
 	@Test
-	public void checkNotModifiedETag() {
+	public void checkNotModifiedETagForGET() {
 		String eTag = "\"Foo\"";
 		servletRequest.setMethod("GET");
 		servletRequest.addHeader("If-None-Match", eTag );
@@ -151,7 +151,7 @@ public void checkNotModifiedETag() {
 	}
 
 	@Test
-	public void checkModifiedETag() {
+	public void checkModifiedETagForGET() {
 		String currentETag = "\"Foo\"";
 		String oldEtag = "Bar";
 		servletRequest.setMethod("GET");
@@ -163,4 +163,52 @@ public void checkModifiedETag() {
 		assertEquals(currentETag, servletResponse.getHeader("ETag"));
 	}
 
+	@Test
+	public void checkNotModifiedTimeStampForHEAD() {
+		long currentTime = new Date().getTime();
+		servletRequest.setMethod("HEAD");
+		servletRequest.addHeader("If-Modified-Since", currentTime);
+
+		request.checkNotModified(currentTime);
+
+		assertEquals(304, servletResponse.getStatus());
+	}
+
+	@Test
+	public void checkModifiedTimeStampForHEAD() {
+		long currentTime = new Date().getTime();
+		long oneMinuteAgo  = currentTime - (1000 * 60);
+		servletRequest.setMethod("HEAD");
+		servletRequest.addHeader("If-Modified-Since", oneMinuteAgo);
+
+		request.checkNotModified(currentTime);
+
+		assertEquals(200, servletResponse.getStatus());
+		assertEquals(""+currentTime, servletResponse.getHeader("Last-Modified"));
+	}
+
+	@Test
+	public void checkNotModifiedETagForHEAD() {
+		String eTag = "\"Foo\"";
+		servletRequest.setMethod("HEAD");
+		servletRequest.addHeader("If-None-Match", eTag );
+
+		request.checkNotModified(eTag);
+
+		assertEquals(304, servletResponse.getStatus());
+	}
+
+	@Test
+	public void checkModifiedETagForHEAD() {
+		String currentETag = "\"Foo\"";
+		String oldEtag = "Bar";
+		servletRequest.setMethod("HEAD");
+		servletRequest.addHeader("If-None-Match", oldEtag);
+
+		request.checkNotModified(currentETag);
+
+		assertEquals(200, servletResponse.getStatus());
+		assertEquals(currentETag, servletResponse.getHeader("ETag"));
+	}
+
 }