Close InputStreams in writeResourceRegionCollection (analogous to writeResourceRegion)

Issue: SPR-15559
(cherry picked from commit eaac348)

Author: jhoeller

spring-web/src/main/java/org/springframework/http/converter/ResourceRegionHttpMessageConverter.java

@@ -38,6 +38,7 @@
  * or Collections of {@link ResourceRegion ResourceRegions}.
  *
  * @author Brian Clozel
+ * @author Juergen Hoeller
  * @since 4.3
  */
 public class ResourceRegionHttpMessageConverter extends AbstractGenericHttpMessageConverter<Object> {
@@ -54,12 +55,12 @@ public ResourceRegionHttpMessageConverter() {
 	@SuppressWarnings("unchecked")
 	protected MediaType getDefaultContentType(Object object) {
 		if (jafPresent) {
-			if(object instanceof ResourceRegion) {
+			if (object instanceof ResourceRegion) {
 				return ActivationMediaTypeFactory.getMediaType(((ResourceRegion) object).getResource());
 			}
 			else {
 				Collection<ResourceRegion> regions = (Collection<ResourceRegion>) object;
-				if(regions.size() > 0) {
+				if (!regions.isEmpty()) {
 					return ActivationMediaTypeFactory.getMediaType(regions.iterator().next().getResource());
 				}
 			}
@@ -143,13 +144,15 @@ protected void writeInternal(Object object, Type type, HttpOutputMessage outputM
 	protected void writeResourceRegion(ResourceRegion region, HttpOutputMessage outputMessage) throws IOException {
 		Assert.notNull(region, "ResourceRegion must not be null");
 		HttpHeaders responseHeaders = outputMessage.getHeaders();
+
 		long start = region.getPosition();
 		long end = start + region.getCount() - 1;
 		Long resourceLength = region.getResource().contentLength();
 		end = Math.min(end, resourceLength - 1);
 		long rangeLength = end - start + 1;
 		responseHeaders.add("Content-Range", "bytes " + start + '-' + end + '/' + resourceLength);
 		responseHeaders.setContentLength(rangeLength);
+
 		InputStream in = region.getResource().getInputStream();
 		try {
 			StreamUtils.copyRange(in, outputMessage.getBody(), start, end);
@@ -169,30 +172,43 @@ private void writeResourceRegionCollection(Collection<ResourceRegion> resourceRe
 
 		Assert.notNull(resourceRegions, "Collection of ResourceRegion should not be null");
 		HttpHeaders responseHeaders = outputMessage.getHeaders();
+
 		MediaType contentType = responseHeaders.getContentType();
 		String boundaryString = MimeTypeUtils.generateMultipartBoundaryString();
 		responseHeaders.set(HttpHeaders.CONTENT_TYPE, "multipart/byteranges; boundary=" + boundaryString);
 		OutputStream out = outputMessage.getBody();
+
 		for (ResourceRegion region : resourceRegions) {
 			long start = region.getPosition();
 			long end = start + region.getCount() - 1;
 			InputStream in = region.getResource().getInputStream();
-			// Writing MIME header.
-			println(out);
-			print(out, "--" + boundaryString);
-			println(out);
-			if (contentType != null) {
-				print(out, "Content-Type: " + contentType.toString());
+			try {
+				// Writing MIME header.
+				println(out);
+				print(out, "--" + boundaryString);
 				println(out);
+				if (contentType != null) {
+					print(out, "Content-Type: " + contentType.toString());
+					println(out);
+				}
+				Long resourceLength = region.getResource().contentLength();
+				end = Math.min(end, resourceLength - 1);
+				print(out, "Content-Range: bytes " + start + '-' + end + '/' + resourceLength);
+				println(out);
+				println(out);
+				// Printing content
+				StreamUtils.copyRange(in, out, start, end);
+			}
+			finally {
+				try {
+					in.close();
+				}
+				catch (IOException ex) {
+					// ignore
+				}
 			}
-			Long resourceLength = region.getResource().contentLength();
-			end = Math.min(end, resourceLength - 1);
-			print(out, "Content-Range: bytes " + start + '-' + end + '/' + resourceLength);
-			println(out);
-			println(out);
-			// Printing content
-			StreamUtils.copyRange(in, out, start, end);
 		}
+
 		println(out);
 		print(out, "--" + boundaryString + "--");
 	}