获取年月日，格式“20170428”

var now=new Date();
var yue = (now.getMonth()+1).length > 2 ? (now.getMonth()+1):"0"+(now.getMonth()+1);
var ntime = now.getFullYear().toString()+yue+now.getDate().toString();

alert(ntime);

//20170428

Date d = new Date();

int year = d.getYear();  //117

int mon = d.getMonth()+1;   //4

int date = d.getDate();

转换成字符串拼接：117428

Date d = new Date();

SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");

system.out.println(sdf.format(d));

//20170428

Calendar now = Calendar.getInstance();

system.out.println("年月日:"+now.get(Calendar.YEAR)+(now.get(Calendar.MONTH)+1)+now.get(Calendar.DAY_OF_MONTH));

//(now.get(Calendar.MONTH)+1)  //4

//2017428