ResponseEntity provides static "badRequest()" convenience method as well

Issue: SPR-12112

spring-web/src/main/java/org/springframework/http/ResponseEntity.java

@@ -228,6 +228,15 @@ public class ResponseEntity<T> extends HttpEntity<T> {
 		return status(HttpStatus.NO_CONTENT);
 	}
 
+	/**
+	 * Creates a builder with a {@link HttpStatus#BAD_REQUEST} status.
+	 * @return the created builder
+	 * @since 4.1
+	 */
+	public static BodyBuilder badRequest() {
+		return status(HttpStatus.BAD_REQUEST);
+	}
+
 	/**
 	 * Creates a builder with a {@link HttpStatus#NOT_FOUND NOT_FOUND} status.
 	 * @return the created builder