[深圳|结业弟子]JAVA-张庆东|2017年10月05日的日报-技能树.IT修真院

发表于： 2017-10-05 20:02:30

4 874

今天完成的事情：

1.完成了拦截器拦截并根据session中的信息判断用户是否登录的一个demo

控制器：

@RequestMapping(value = "/login", method = RequestMethod.POST)
public ModelAndView login(@Param("username")String username,@Param("password")String password,HttpServletRequest request,HttpServletResponse response) {
   ModelAndView mv = new ModelAndView();
    User realUser = null;
    realUser = userService.selectUserByName(username);
    if (realUser != null && realUser.getPassword().equals(password)) {
   HttpSession session = request.getSession();
        session.setAttribute("message", username);
        mv.setViewName("loginSuccess");
        mv.addObject("username", realUser.getUsername());
        return mv;
    } else {
       mv.setViewName("loginFail");
        return mv;
    }
}

注：这里的判断逻辑应该写在service层

拦截设置:

<!--拦截器-->
<mvc:interceptors>
    <mvc:interceptor>
        <!-- 拦截所有URL中包含/u/的请求 -->
        <mvc:mapping path="/u/**"/>
        <bean class="cn.summerwaves.interceptor.LoginInterceptor"></bean>
    </mvc:interceptor>
</mvc:interceptors>

拦截包含/u/的url

拦截器：

@Override
public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
    String session = (String) httpServletRequest.getSession().getAttribute("message");
    if (session == null) {
      httpServletRequest.getRequestDispatcher("/skip").forward(httpServletRequest, httpServletResponse);
        return false;
    }else
    return true;
}

skipToLogin.jsp

<html>
<head>
    <title>Title</title>
</head>
<body>
<a href="${ctx}/login">未登录，请登陆后查看</a>
<script>
    function jumpurl(){
        location='http://localhost:8080/task5/login';
    }
    setTimeout('jumpurl()',3000);
</script>
</body>
</html>

三秒后跳转到login页

效果：

详见www.summerwaves.cn

2.学习了token是什么

token是一串字符串，一般放在缓存中设置过期时间，然后每次用户访问网页时根据cookie中的token和缓存中的token校对，一致则返回已登录状态，这样大量减少了对数据库的访问，增加了数据库和网站的健壮性

剩下的工作是把写好token放在cookie中，代替上面例子的session，然后再写加密token和加密登录

3.写好了cookie的工具类：

public class CookieUtil {
    private static Map<String, Cookie> ReadCooKieMap(HttpServletRequest request) {
        Map<String, Cookie> cookieMap = new HashMap<String, Cookie>();
        Cookie[] cookies = request.getCookies();
        if (cookies != null) {
                   for (Cookie cookie : cookies) {
           cookieMap.put(cookie.getName(), cookie);
            }
        }
        return cookieMap;
    }

    public static Cookie getCookieByName(HttpServletRequest request, String name) {
        Map<String, Cookie> cookieMap = ReadCooKieMap(request);
        if (cookieMap.containsKey(name)) {
           Cookie cookie = cookieMap.get(name);
            return cookie;
        }
        return null;
    }

    public static Cookie creatCookie(String name, String value, Integer expire) throws UnsupportedEncodingException {
        Cookie cookie = new Cookie(name.trim(), URLEncoder.encode(value.trim(),"UTF-8"));
        cookie.setMaxAge(expire);
        cookie.setPath("/");
        return cookie;
    }

    public static String getCookieValueByName(HttpServletRequest request,String name) throws UnsupportedEncodingException {
        Cookie cookie = getCookieByName(request, name);
        if (cookie != null && StringUtils.isNotBlank(cookie.getValue())) {
                        return URLEncoder.encode(cookie.getValue(), "UTF-8");
        } else if (cookie.getValue() != null) {
                   return "";
        } else {
                   return null;
        }
    }

    public static Cookie modCookieByName(HttpServletRequest request, String name,String value, Integer expire, boolean creatd) throws UnsupportedEncodingException {
        Cookie cookie = getCookieByName(request, name);
        if (cookie != null) {
           cookie.setMaxAge(expire);
            cookie.setValue(URLEncoder.encode(value, "UTF-8"));
        } else if (cookie == null){
                       if (creatd) {
              cookie = creatCookie(name, value, expire);
            }
       }
                   return cookie;
    }
}