Process URL path for filename extraction if URI does not expose path

Closes gh-31718

Author: jhoeller

spring-core/src/main/java/org/springframework/core/io/UrlResource.java

@@ -332,13 +332,15 @@ protected URL createRelativeURL(String relativePath) throws MalformedURLExceptio
 	@Nullable
 	public String getFilename() {
 		if (this.uri != null) {
-			// URI path is decoded and has standard separators
-			return StringUtils.getFilename(this.uri.getPath());
-		}
-		else {
-			String filename = StringUtils.getFilename(StringUtils.cleanPath(this.url.getPath()));
-			return (filename != null ? URLDecoder.decode(filename, StandardCharsets.UTF_8) : null);
+			String path = this.uri.getPath();
+			if (path != null) {
+				// Prefer URI path: decoded and has standard separators
+				return StringUtils.getFilename(this.uri.getPath());
+			}
 		}
+		// Otherwise, process URL path
+		String filename = StringUtils.getFilename(StringUtils.cleanPath(this.url.getPath()));
+		return (filename != null ? URLDecoder.decode(filename, StandardCharsets.UTF_8) : null);
 	}
 
 	/**

spring-core/src/test/java/org/springframework/core/io/ResourceTests.java

@@ -302,11 +302,28 @@ void sameResourceWithRelativePathIsEqual() throws Exception {
 
 		@Test
 		void filenameIsExtractedFromFilePath() throws Exception {
+			assertThat(new UrlResource("file:test?argh").getFilename()).isEqualTo("test");
+			assertThat(new UrlResource("file:/test?argh").getFilename()).isEqualTo("test");
+			assertThat(new UrlResource("file:test.txt?argh").getFilename()).isEqualTo("test.txt");
+			assertThat(new UrlResource("file:/test.txt?argh").getFilename()).isEqualTo("test.txt");
+			assertThat(new UrlResource("file:/dir/test?argh").getFilename()).isEqualTo("test");
 			assertThat(new UrlResource("file:/dir/test.txt?argh").getFilename()).isEqualTo("test.txt");
 			assertThat(new UrlResource("file:\\dir\\test.txt?argh").getFilename()).isEqualTo("test.txt");
 			assertThat(new UrlResource("file:\\dir/test.txt?argh").getFilename()).isEqualTo("test.txt");
 		}
 
+		@Test
+		void filenameIsExtractedFromURL() throws Exception {
+			assertThat(new UrlResource(new URL("file:test?argh")).getFilename()).isEqualTo("test");
+			assertThat(new UrlResource(new URL("file:/test?argh")).getFilename()).isEqualTo("test");
+			assertThat(new UrlResource(new URL("file:test.txt?argh")).getFilename()).isEqualTo("test.txt");
+			assertThat(new UrlResource(new URL("file:/test.txt?argh")).getFilename()).isEqualTo("test.txt");
+			assertThat(new UrlResource(new URL("file:/dir/test?argh")).getFilename()).isEqualTo("test");
+			assertThat(new UrlResource(new URL("file:/dir/test.txt?argh")).getFilename()).isEqualTo("test.txt");
+			assertThat(new UrlResource(new URL("file:\\dir\\test.txt?argh")).getFilename()).isEqualTo("test.txt");
+			assertThat(new UrlResource(new URL("file:\\dir/test.txt?argh")).getFilename()).isEqualTo("test.txt");
+		}
+
 		@Test
 		void filenameContainingHashTagIsExtractedFromFilePathUnencoded() throws Exception {
 			String unencodedPath = "/dir/test#1.txt";