Consistently close streams through try-with-resources

Closes gh-36223

spring-core/src/main/java/org/springframework/util/FileCopyUtils.java

@@ -16,7 +16,6 @@
 
 package org.springframework.util;
 
-import java.io.Closeable;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
@@ -29,9 +28,11 @@ import java.nio.file.Files;
 import org.jspecify.annotations.Nullable;
 
 /**
- * Simple utility methods for file and stream copying. All copy methods use a block size
- * of 4096 bytes, and close all affected streams when done. A variation of the copy
- * methods from this class that leave streams open can be found in {@link StreamUtils}.
+ * Simple utility methods for file and stream copying.
+ *
+ * <p>All copy methods use a block size of {@value #BUFFER_SIZE} bytes and
+ * close all affected streams when done. A variation of the copy methods from
+ * this class that leave streams open can be found in {@link StreamUtils}.
  *
  * <p>Mainly for use within the framework, but also useful for application code.
  *
@@ -124,12 +125,9 @@ public abstract class FileCopyUtils {
 		Assert.notNull(in, "No input byte array specified");
 		Assert.notNull(out, "No OutputStream specified");
 
-		try {
+		try (out) {
 			out.write(in);
 		}
-		finally {
-			close(out);
-		}
 	}
 
 	/**
@@ -166,15 +164,11 @@ public abstract class FileCopyUtils {
 		Assert.notNull(in, "No Reader specified");
 		Assert.notNull(out, "No Writer specified");
 
-		try {
+		try (in; out) {
 			int charCount = (int) in.transferTo(out);
 			out.flush();
 			return charCount;
 		}
-		finally {
-			close(in);
-			close(out);
-		}
 	}
 
 	/**
@@ -188,12 +182,9 @@ public abstract class FileCopyUtils {
 		Assert.notNull(in, "No input String specified");
 		Assert.notNull(out, "No Writer specified");
 
-		try {
+		try (out) {
 			out.write(in);
 		}
-		finally {
-			close(out);
-		}
 	}
 
 	/**
@@ -213,17 +204,4 @@ public abstract class FileCopyUtils {
 		return out.toString();
 	}
 
-	/**
-	 * Attempt to close the supplied {@link Closeable}, silently swallowing any
-	 * exceptions.
-	 * @param closeable the {@code Closeable} to close
-	 */
-	private static void close(Closeable closeable) {
-		try {
-			closeable.close();
-		}
-		catch (IOException ignored) {
-		}
-	}
-
 }