From e1200f34e735769fcc9bac86059d56312460e132 Mon Sep 17 00:00:00 2001
From: Marten Deinum <mdeinum@gmail.com>
Date: Thu, 16 Dec 2021 07:10:12 +0100
Subject: [PATCH] Use try-with-resources for AutoClosables where feasible

Where unfeasible, this commit adds inline comments to explain why
try-with-resources must not be used in certain scenarios. The purpose
of the comments is to avoid accidental conversion to try-with-resources
at a later date.

Closes gh-27823
---
 .../context/index/processor/MetadataStore.java               | 5 +----
 .../core/LocalVariableTableParameterNameDiscoverer.java      | 2 ++
 .../http/converter/BufferedImageHttpMessageConverter.java    | 2 ++
 .../http/converter/ResourceHttpMessageConverter.java         | 2 ++
 .../http/converter/ResourceRegionHttpMessageConverter.java   | 2 ++
 .../web/socket/messaging/StompSubProtocolHandler.java        | 2 ++
 6 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/spring-context-indexer/src/main/java/org/springframework/context/index/processor/MetadataStore.java b/spring-context-indexer/src/main/java/org/springframework/context/index/processor/MetadataStore.java
index c00f682b77..8593fc7508 100644
--- a/spring-context-indexer/src/main/java/org/springframework/context/index/processor/MetadataStore.java
+++ b/spring-context-indexer/src/main/java/org/springframework/context/index/processor/MetadataStore.java
@@ -62,12 +62,9 @@ class MetadataStore {
 
 
 	private CandidateComponentsMetadata readMetadata(InputStream in) throws IOException {
-		try {
+		try (in){
 			return PropertiesMarshaller.read(in);
 		}
-		finally {
-			in.close();
-		}
 	}
 
 	private FileObject getMetadataResource() throws IOException {
diff --git a/spring-core/src/main/java/org/springframework/core/LocalVariableTableParameterNameDiscoverer.java b/spring-core/src/main/java/org/springframework/core/LocalVariableTableParameterNameDiscoverer.java
index 6498a35f56..70a2a6adf6 100644
--- a/spring-core/src/main/java/org/springframework/core/LocalVariableTableParameterNameDiscoverer.java
+++ b/spring-core/src/main/java/org/springframework/core/LocalVariableTableParameterNameDiscoverer.java
@@ -101,6 +101,8 @@ public class LocalVariableTableParameterNameDiscoverer implements ParameterNameD
 			}
 			return NO_DEBUG_INFO_MAP;
 		}
+		// We cannot use try-with-resources here as, potential, exception upon closing
+		// would still bubble up the stack
 		try {
 			ClassReader classReader = new ClassReader(is);
 			Map<Executable, String[]> map = new ConcurrentHashMap<>(32);
diff --git a/spring-web/src/main/java/org/springframework/http/converter/BufferedImageHttpMessageConverter.java b/spring-web/src/main/java/org/springframework/http/converter/BufferedImageHttpMessageConverter.java
index cdfa5781c9..7a020f25c0 100644
--- a/spring-web/src/main/java/org/springframework/http/converter/BufferedImageHttpMessageConverter.java
+++ b/spring-web/src/main/java/org/springframework/http/converter/BufferedImageHttpMessageConverter.java
@@ -169,6 +169,8 @@ public class BufferedImageHttpMessageConverter implements HttpMessageConverter<B
 
 		ImageInputStream imageInputStream = null;
 		ImageReader imageReader = null;
+		// We cannot use try-with-resources here as, potential, exception upon closing
+		// would still bubble up the stack
 		try {
 			imageInputStream = createImageInputStream(inputMessage.getBody());
 			MediaType contentType = inputMessage.getHeaders().getContentType();
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 f587aecf7f..08e4027c64 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
@@ -131,6 +131,8 @@ public class ResourceHttpMessageConverter extends AbstractHttpMessageConverter<R
 
 	protected void writeContent(Resource resource, HttpOutputMessage outputMessage)
 			throws IOException, HttpMessageNotWritableException {
+		// We cannot use try-with-resources here as, potential, exception upon closing
+		// would still bubble up the stack
 		try {
 			InputStream in = resource.getInputStream();
 			try {
diff --git a/spring-web/src/main/java/org/springframework/http/converter/ResourceRegionHttpMessageConverter.java b/spring-web/src/main/java/org/springframework/http/converter/ResourceRegionHttpMessageConverter.java
index b9dca72204..972f1289e5 100644
--- a/spring-web/src/main/java/org/springframework/http/converter/ResourceRegionHttpMessageConverter.java
+++ b/spring-web/src/main/java/org/springframework/http/converter/ResourceRegionHttpMessageConverter.java
@@ -155,6 +155,8 @@ public class ResourceRegionHttpMessageConverter extends AbstractGenericHttpMessa
 		responseHeaders.setContentLength(rangeLength);
 
 		InputStream in = region.getResource().getInputStream();
+		// We cannot use try-with-resources here as, potential, exception upon closing
+		// would still bubble up the stack
 		try {
 			StreamUtils.copyRange(in, outputMessage.getBody(), start, end);
 		}
diff --git a/spring-websocket/src/main/java/org/springframework/web/socket/messaging/StompSubProtocolHandler.java b/spring-websocket/src/main/java/org/springframework/web/socket/messaging/StompSubProtocolHandler.java
index 08991986c8..873f99539e 100644
--- a/spring-websocket/src/main/java/org/springframework/web/socket/messaging/StompSubProtocolHandler.java
+++ b/spring-websocket/src/main/java/org/springframework/web/socket/messaging/StompSubProtocolHandler.java
@@ -374,6 +374,8 @@ public class StompSubProtocolHandler implements SubProtocolHandler, ApplicationE
 		headerAccessor.setMessage(error.getMessage());
 
 		byte[] bytes = this.stompEncoder.encode(headerAccessor.getMessageHeaders(), EMPTY_PAYLOAD);
+		// We cannot use try-with-resources here as, potential, exception upon closing
+		// would still bubble up the stack
 		try {
 			session.sendMessage(new TextMessage(bytes));
 		}