It precedes the message with Exception name also.
The following piece of code:
    public static void main(String str[]) {
        Exception e = new Exception();
        System.out.println("Message:<" + e.getMessage() + ">");
        FactoryConfigurationError fce = new FactoryConfigurationError(e);
        System.out.println("Message:<" + fce.getMessage() + ">");

        e = new Exception("My Message");
        System.out.println("Message:<" + e.getMessage() + ">");
        fce = new FactoryConfigurationError(e);
        System.out.println("Message:<" + fce.getMessage() + ">");
    }
throws the following output:

Message:<null>
Message:<java.lang.Exception>
Message:<My Message>
Message:<java.lang.Exception: My Message>