public String getString() {
String pkValue;
String str = new SimpleDateFormat("yyyyMMddHHmmssSSS").format(new Date());
int rannum = (int) (new Random().nextDouble() * (999 - 100 + 1)) + 100;// 获取3位随机数
// pkValue= UUID.randomUUID().toString().replace("-","");
pkValue= str+rannum;
return pkValue;
}