java.util.Date与SimpleDateFormat的

实际使用示例

SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss MM/dd/yyyy");
return result = dateFormat.format(new Date());
// result = "17:33:56 01/21/2017"

拓展：java.util.Calendar类（同样可以获取时间）

// 获取当前的时间
Calendar calendar = new GregorianCalendar();
String am_pm;
int hour = calendar.get(Calendar.HOUR);
int minute = calendar.get(Calendar.MINUTE);
int second = calendar.get(Calendar.SECOND);
if(calendar.get(Calendar.AM_PM) == 0)
  am_pm = "AM";
else
  am_pm = "PM";
String CT = hour+":"+ minute +":"+ second +" "+ am_pm;

常用的匹配规则