Here you can find the source of formatterFor(final Thread t)
private static final SimpleDateFormat formatterFor(final Thread t)
//package com.java2s; //License from project: Open Source License import java.text.SimpleDateFormat; import java.util.Map; public class Main { private static Map<Thread, SimpleDateFormat> formatters; private static final SimpleDateFormat formatterFor(final Thread t) { final SimpleDateFormat tmp = formatters.get(t); if (tmp != null) { return tmp; }//from w w w . j a v a 2 s .c o m final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("'D:'yyyyMMddHHmmssZ"); formatters.put(t, DATE_FORMAT); return DATE_FORMAT; } }