JAVA把毫秒数转换成日期
systemMillonSenconds = System.currentTimeMillis();
long sd=1345185923140L;
Date dat=new Date(sd);
GregorianCalendar gc = new GregorianCalendar();
gc.setTime(dat);
java.text.SimpleDateFormat format = new java.text.SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
String sb=format.format(gc.getTime());
System.out.println(sb);
dat.toString() );