From d66206704e70a50ef671efbf8a5406c56963f91b 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 81733712488..386ca52e36e 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 8d8f38516bf..f8c60a94b4b 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()));
+	}
+
 }