通過一個integer類型屬性來表示對象所處的狀態：
CASE:
Invitor:邀請者對象模型
Integer Invitor.joinstatus:邀請者所處參加狀態
當前存在狀態聲明：是否被邀請，是否注冊用戶，是否拒絕，是否審批
設計思路：
bit0: 1-invited? , 0-not invited
bit1: 1-registed , 0-not registed
bit2: 1-refused? , 0-not refused
bit3: 1-approved , 0-not approved
Example:0111(7)=the invitor is invited ,and is registed ,and has been refused without approved.
//判斷joinstatus狀態
public static String theStatusOfApplicant(Invitor iv) throws TrainingAppException {
??String status = "default";
??if (((iv.getJoinStatus() & 0x8) == 0) && ((iv.getJoinStatus() & 0x4) == 0)) {
???status = "default";// 待批準(0x0)
??}
??if (((iv.getJoinStatus() & 0x8) == 0x8) && ((iv.getJoinStatus() & 0x4) == 0)) {
???status = "approved";// 已審批(0x4)
??}
??if (((iv.getJoinStatus() & 0x4) > 0) && ((iv.getJoinStatus() & 0x8) == 0)) {
???status = "refused";// 已拒絕(0x8)
??}
??return status;
?}
//更新joinstatus狀態(審批和拒絕為互斥)
private void updateJoinstatus(MainTrainingInfo mtrInfo, List<Invitor> invitors, Integer opertorType) {
??for (Iterator it = invitors.iterator(); it.hasNext();) {
???Invitor iv = (Invitor) it.next();
???if (APPLY_OPERTORTYPE_APPROVE == opertorType.intValue()) { // approve
????iv.setJoinStatus((iv.getJoinStatus() | 0x8) & 0x8);
???} else {
????iv.setJoinStatus((iv.getJoinStatus() | 0x4) & 0x4); // refuse
???}
???iv.setMainId(mtrInfo);
???mtrInfo.getInvitor().add(iv);
??}
??persistence.update(mtrInfo);
??if (APPLY_OPERTORTYPE_APPROVE == opertorType.intValue()) { // approve
???log.info(" ### 申請已獲批準,發送邀請郵件.");
???// Send Mails.
???try {
????instanceMailSendService.approveInvitorSendMail(mtrInfo, invitors, getHostEmail(mtrInfo),
??????MainTrainingInfoUtil.getLocale(mtrInfo), true, true);
???} catch (Exception e) {
????log.error(e.toString());
???}
??}
?}