Java自动生成编号的方法步骤

SimpleDateFORMat f = new
SimpleDateFormat("yyyyMMdd");//设置日期格式
String date = f.format(new Date(System.currentTimeMillis()));

String sql = "select * from dailyincome where dailyincomenumber like 'SR"+date+"%' order by dailyincomenumber desc";

List<DailyIncome> DailyIncome = dailyincomeService.SelectDailyIncome();//调用Service中的方法
if(DailyIncome.size() > 0){
	String n = DailyIncome.get(0).getDailyincomenumber();
	int intNumber = Integer.parseInt(n.substring(10));
	intNumber++;
	String Number = String.valueOf(intNumber);
	for (int i = 0; i < 3; i++){
		String Number = Number.length() < 3 ? "0" + Number : Number;
	}
	String Number = "SR" + date + Number;
}else{
	String Number = "SR" + date + "001";
}