[java] java create date object using a value string

What you're basically trying to do is this:-

Calendar cal = Calendar.getInstance();
Date date = cal.getTime();

The reason being, the String which you're printing is just a String representation of the Date in your required format. If you try to convert it to date, you'll eventually end up doing what I've mentioned above.

Formatting Date(cal.getTime()) to a String and trying to get back a Date from it - makes no sense. Date has no format as such. You can only get a String representation of that using the SDF.