From a17912d19ec3a0468bd8509dd215f10696b96dc1 Mon Sep 17 00:00:00 2001
From: Gabriel Axel <guznik@gmail.com>
Date: Wed, 21 Aug 2013 15:21:19 +0300
Subject: [PATCH] Fix NPE in ResourceHttpMessageConverter

ResourceHttpMessageConverter tries to use the filename to determine the
media type, but for Resource implementations such as ByteArrayResource
it is null, which causes NullPointerException. The fix checks whether
getFilename returns null before attempting to determine the media type
by it.

Issue: SPR-10848
---
 .../converter/ResourceHttpMessageConverter.java |  3 +++
 .../ResourceHttpMessageConverterTests.java      | 17 +++++++++++++++--
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/spring-web/src/main/java/org/springframework/http/converter/ResourceHttpMessageConverter.java b/spring-web/src/main/java/org/springframework/http/converter/ResourceHttpMessageConverter.java
index 8173371248..386ca52e36 100644
--- a/spring-web/src/main/java/org/springframework/http/converter/ResourceHttpMessageConverter.java
+++ b/spring-web/src/main/java/org/springframework/http/converter/ResourceHttpMessageConverter.java
@@ -138,6 +138,9 @@ public class ResourceHttpMessageConverter extends AbstractHttpMessageConverter<R
 		}
 
 		public static MediaType getMediaType(Resource resource) {
+			if(resource.getFilename() == null) {
+				return null;
+			}
 			String mediaType = fileTypeMap.getContentType(resource.getFilename());
 			return (StringUtils.hasText(mediaType) ? MediaType.parseMediaType(mediaType) : null);
 		}
diff --git a/spring-web/src/test/java/org/springframework/http/converter/ResourceHttpMessageConverterTests.java b/spring-web/src/test/java/org/springframework/http/converter/ResourceHttpMessageConverterTests.java
index 8d8f38516b..f8c60a94b4 100644
--- a/spring-web/src/test/java/org/springframework/http/converter/ResourceHttpMessageConverterTests.java
+++ b/spring-web/src/test/java/org/springframework/http/converter/ResourceHttpMessageConverterTests.java
@@ -17,11 +17,11 @@
 package org.springframework.http.converter;
 
 import java.io.IOException;
+import java.util.Arrays;
 
-import static org.junit.Assert.*;
 import org.junit.Before;
 import org.junit.Test;
-
+import org.springframework.core.io.ByteArrayResource;
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 import org.springframework.http.MediaType;
@@ -29,6 +29,8 @@ import org.springframework.http.MockHttpInputMessage;
 import org.springframework.http.MockHttpOutputMessage;
 import org.springframework.util.FileCopyUtils;
 
+import static org.junit.Assert.*;
+
 /**
  * @author Arjen Poutsma
  */
@@ -70,4 +72,15 @@ public class ResourceHttpMessageConverterTests {
 		assertEquals("Invalid content-length", body.getFile().length(), outputMessage.getHeaders().getContentLength());
 	}
 
+	// SPR-10848
+
+	@Test
+	public void writeByteArrayNullMediaType() throws IOException {
+		MockHttpOutputMessage outputMessage = new MockHttpOutputMessage();
+		byte[] byteArray = {1, 2, 3};
+		Resource body = new ByteArrayResource(byteArray);
+		converter.write(body, null, outputMessage);
+		assertTrue(Arrays.equals(byteArray, outputMessage.getBodyAsBytes()));
+	}
+
 }