springboot后台session的存储与取出方式

//将数据存入session
public class SetSessionUtil {
    public static void setSession(HttpServletRequest request,String SessionName,String SessionValue) {
        HttpSession session = request.getSession();
        session.setAttribute(SessionName,SessionValue);
    }
}

//获取session
public class GetSessionUtil {
    public static String getSession(HttpServletRequest request, String sessionName) {
        HttpSession session = request.getSession();
        String sessionValue = (String) session.getAttribute(sessionName);
        return sessionValue;
    }
}

HttpSession session = HttpServletRequest.getSession();
session.invalidate();

<img th:src="${session.head_pic}">

@RequestMapping("/login")
    public String login(HttpServletRequest request, @RequestParam("userName") String userName, @RequestParam("passWord") String passWord) {
        String res = userService.check_userName(userName);
        if (!res.equals("registed")) {
            return "userName has not registed";
        }    
        String str = userService.check_userName_and_passWord(userName, passWord);
        if (str.equals("success")){
            //第一步：获取session
            HttpSession session = request.getSession();
            //第二步：将想要保存到数据存入session中
            session.setAttribute("userName",userName);
            session.setAttribute("password",passWord);
            //这样就完成了用户名和密码保存到session的操作
        }
        return str;
    }

@RequestMapping("/index")
public class IndexController {

    @Autowired
    HttpServletRequest request; //通过注解获取一个request
    
    @RequestMapping("/getName")
    public String getName() {
        //通过request来获取保存在session中的用户名
        String userName = (String) request.getSession().getAttribute("userName");
        System.out.println(userName);
        return userName;
    }
}