字符串“Mon Dec 31 00:00:00 CST 2012”转换成日期有关问题

import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;import java.util.Locale;public class Test {    public static void main(String[] args) {        String str = "Mon Dec 31 00:00:00 CST 2012";        Date date = parse(str, "EEE MMM dd HH:mm:ss zzz yyyy", Locale.US);        System.out.printf("%tF %<tT%n", date);    }    public static Date parse(String str, String pattern, Locale locale) {        if(str == null || pattern == null) {            return null;        }        try {            return new SimpleDateFormat(pattern, locale).parse(str);        } catch (ParseException e) {            e.printStackTrace();        }        return null;    }    public static String format(Date date, String pattern, Locale locale) {        if(date == null || pattern == null) {            return null;        }        return new SimpleDateFormat(pattern, locale).format(date);    }}