SpringMvc中的拦截器

1.拦截器的简单介绍 2.拦截器的两种实现方式

2.1实现接口HandlerInterceptor

public class MyInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
        System.out.println("handle方法执行前。。。。");
        return true;
        //true:执行handler方法
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
        System.out.println("handler方法执行后， 视图生成前。。。。");
    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
        System.out.println("目标handler方法执行后，视图生成之后执行此方法");
    }
}

2.2继承HandlerInterceptorAdapter

public class MyInterceptor2 extends HandlerInterceptorAdapter {
    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
        System.out.println("MyInterceptor2方法执行前。。。。");
        return true;
        //true:执行handler方法
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
        System.out.println("MyInterceptor2方法执行后， 视图生成前。。。。");
    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
        System.out.println("MyInterceptor2方法执行后，视图生成之后执行此方法");
    }
}

3.配置文件中的内容

<mvc:interceptors>
    <mvc:interceptor>
        <!--拦截所有-->
        <mvc:mapping path="/**"/>
        <!--进行放行的页面-->
        <mvc:exclude-mapping path="/user/login"/>
          <!--设置实现哪一个拦截器-->
        <bean class="org.example.springmvc.interceptor.ReigsterInterceptor"></bean>
    </mvc:interceptor>
</mvc:interceptors>