public static boolean isJarFileURL(URL url) {
        return (URL_PROTOCOL_FILE.equals(url.getProtocol()) &&
                url.getPath().toLowerCase().endsWith(JAR_FILE_EXTENSION));
    }
public static boolean isJarFileURL ( URL url ) { return ( URL_PROTOCOL_FILE . equals ( url . getProtocol ( ) ) && url . getPath ( ) . toLowerCase ( ) . endsWith ( JAR_FILE_EXTENSION ) ) ; }
Determine whether the given URL points to a jar file itself,
that is, has protocol "file" and ends with the ".jar" extension.

@param url the URL to check
@return whether the URL has been identified as a JAR file URL
@since 4.1