springmvc拦截器的配置

登陆认证拦截实现

 代码实现

@Controller
public class LoginController {
    @RequestMapping("/login")
    public String login(HttpSession session,String username,String password) throws Exception {
        
         session.setAttribute("username", username);
         return "redirect:items/queryItems.action";
    }
    
    @RequestMapping("/logout")
    public String logout(HttpSession session) throws Exception {
        session.invalidate();
        return "redirect:/items/queryItems.action";
    }
}

LoginInterceptor.java

public class LoginInterceptor implements HandlerInterceptor {
    
    //在进入handler方法之前执行
    //用于身份认证，身份授权 认认证不通过，拦截，不再向下执行
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        
        String url = request.getRequestURI();
        //判断url是否是公开地址 在这里就是登录提交的地址
        if(url.indexOf("login.action") >= 0){
            //放行
            return true;
        }
        
        HttpSession session = request.getSession();
        String username = (String) session.getAttribute("username");
        if(username != null){
            return true;
        }
        //失败，跳转登录页面
        request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request, response);
        //false表示拦截 true表示放行
        return false;
    }
    
    //进入handler方法之后，返回modelandview之前执行
    //将公用的模型数据传到视图，也可以在这里统一视图
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView)
            throws Exception {
        System.out.println("Interceptor......postHandle");
    }

    //执行完handler方法之后执行
    //使用统一的异常处理，统一的日志处理
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception {
        System.out.println("Interceptor......afterCompletion");
    }
    
}

 拦截器配置

<!--拦截器 -->
<mvc:interceptors>
    <!--多个拦截器,顺序执行 -->
    <!-- 登陆认证拦截器 -->
    <mvc:interceptor>
        <mvc:mapping path="/**"/>
        <bean class="cn.cuibusi.ssm.interceptor.LoginInterceptor"></bean>
    </mvc:interceptor>
</mvc:interceptors>