SpringMvc拦截器_拦截器只会针对访问springmvc做拦截

拦截器：只会拦截springmvc的控制层接口路径

自定义拦截器类

       返回 true为通过 fales 为拦截

public class Myinterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("-=======拦截器======-");
        return true;
    }
}

将拦截器放到springMvc容器中 springmvc.xml

<!--拦截器-->
    <mvc:interceptors>
        <mvc:interceptor>
            //拦截的路径 /*一层路径
                        /**多层路径
            <mvc:mapping path="/**"/>
         
            <mvc:exclude-mapping path="不拦截路径"/>
         
            <bean class="拦截器全路径"/>
        </mvc:interceptor>
    </mvc:interceptors>

案例：

        不登录能访问student/list 不能访问student/a，student/b

       登录后能访问student/a，student/b

@Controller
@RequestMapping("/student")
public class Hellocontroller {
 
    @RequestMapping("/a")
    @ResponseBody
    public String a(){
        return "登录后才能访问a";
    }
    @RequestMapping("/b")
    @ResponseBody
    public String b(){
        return "登录后才能访问b";
    }
    @RequestMapping("/list")
    @ResponseBody
    public String list(){
        return "不登录也能访问list";
    }
}

login.jsp 登录页面

登录页面的控制层

@Controller
@RequestMapping("/login")
public class Logincontroller {
 
    @RequestMapping("/login")
    public String login(String name, String password, HttpSession session){
        if ("admin".equals(name)&&"123".equals(password)){
            session.setAttribute("name",name);
            return "error";
        }else {
            return "forward:../login.jsp";
        }
    }
}

 拦截器

public class Loginhandle implements HandlerInterceptor {
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        HttpSession session = request.getSession();
        Object name = session.getAttribute("name");
        if (name!=null){
            return true;
        }else
            response.sendRedirect(request.getContextPath()+"/login.jsp");
        return false;
    }
}

声明拦截器

 <!--声明自定义拦截器-->
    <mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/**"/>
            <mvc:exclude-mapping path="/student/list"/>
            <mvc:exclude-mapping path="/login/login"/>
            <bean class="com.rqk.aaa.qy145.ninth.rqk.handler.Loginhandle"/>
        </mvc:interceptor>
    </mvc:interceptors>