今天的关于session的学习

修改用户信息：
public String edit(){
if(null == this.getAddOrModify() || "".equals(this.getAddOrModify().toString())){
UserInfo userInfo = (UserInfo)this.getSession().getAttribute("user");
this.setUserInfo(userInfo);

return "modifyPage";
}else{
if(null != this.getAddOrModify() && "modify".equals(this.getAddOrModify().toString())){
if(null == this.getUserInfo().getId() || "".equals(this.getUserInfo().getId().toString())){
this.setTipMsg("id不能为空");
return "modifyPage";
}
if(null == this.getUserInfo().getMail() || "".equals(this.getUserInfo().getMail().toString())){
this.setTipMsg("邮箱不能为空");
return "modifyPage";
}
if(null == this.getUserInfo().getPwd() || "".equals(this.getUserInfo().getPwd().toString())){
this.setTipMsg("密码不能为空");
return "modifyPage";
}
if(null == this.getUserInfo().getLev() || "".equals(this.getUserInfo().getLev().toString())){
this.setTipMsg("等级不能为空");
return "modifyPage";
}
userInfoService.saveOrUpdateUserInfo(this.getUserInfo());
}

this.setOperateStat("success");
return "modifyPage";

}
｝
重点在从session中获取用用户的信息