How to format a java.sql Timestamp for displaying?

For this particular question, the standard suggestion of java.text.SimpleDateFormat works, but has the unfortunate side effect that SimpleDateFormat is not thread-safe and can be the source of particularly nasty problems since it'll corrupt your output in multi-threaded scenarios, and you won't get any exceptions!

I would strongly recommend looking at Joda for anything like this. Why ? It's a much richer and more intuitive time/date library for Java than the current library (and the basis of the up-and-coming new standard Java date/time library, so you'll be learning a soon-to-be-standard API).

Use String.format (or java.util.Formatter):

Timestamp timestamp = ...
String.format("%1$TD %1$TT", timestamp)

EDIT:
please see the documentation of Formatter to know what TD and TT means: click on java.util.Formatter

The first 'T' stands for:

't', 'T'    date/time   Prefix for date and time conversion characters.

and the character following that 'T':

'T'     Time formatted for the 24-hour clock as "%tH:%tM:%tS".
'D'     Date formatted as "%tm/%td/%ty". 

If you're using MySQL and want the database itself to perform the conversion, use this:

DATE_FORMAT(date,format)

If you prefer to format using Java, use this:

java.text.SimpleDateFormat

SimpleDateFormat dateFormat = new SimpleDateFormat("M/dd/yyyy");
dateFormat.format( new Date() );

java.sql.Timestamp extends java.util.Date. You can do:

String s = new SimpleDateFormat("MM/dd/yyyy").format(myTimestamp);

Or to also include time:

String s = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss").format(myTimestamp);