diff --git a/spring-core/src/main/java/org/springframework/core/io/FileUrlResource.java b/spring-core/src/main/java/org/springframework/core/io/FileUrlResource.java
index 4e1b0fa80936..563a96a21111 100644
--- a/spring-core/src/main/java/org/springframework/core/io/FileUrlResource.java
+++ b/spring-core/src/main/java/org/springframework/core/io/FileUrlResource.java
@@ -59,6 +59,7 @@ public class FileUrlResource extends UrlResource implements WritableResource {
 	 */
 	public FileUrlResource(URL url) {
 		super(url);
+		Assert.isTrue(ResourceUtils.isFileURL(url),"url's protocol must be file or start with vfs");
 	}
 
 	/**
@@ -96,7 +97,7 @@ public boolean isWritable() {
 				return (file.canWrite() && !file.isDirectory());
 			}
 			else {
-				return true;
+				return false;
 			}
 		}
 		catch (IOException ex) {
diff --git a/spring-core/src/test/java/org/springframework/core/io/ResourceTests.java b/spring-core/src/test/java/org/springframework/core/io/ResourceTests.java
index 5a9c8e5d6d95..2f2d22c9af67 100644
--- a/spring-core/src/test/java/org/springframework/core/io/ResourceTests.java
+++ b/spring-core/src/test/java/org/springframework/core/io/ResourceTests.java
@@ -330,4 +330,11 @@ void readableChannelNotFoundOnClassPathResource() throws IOException {
 				new ClassPathResource("Resource.class", getClass()).createRelative("X").readableChannel());
 	}
 
+	@Test
+	void fileUrlResourceTest() throws IOException {
+		assertThatIllegalArgumentException().isThrownBy(() -> {
+			new FileUrlResource(new URL("https://spring.io/"));
+		});
+	}
+
 }