SpringMVC拦截器

spring拦截器

• 是spring Aop的一种应用，在不修改源码的情况下，执行一段代码，以增强现有方法。

样例

• 实现HandlerInterceptor接口

public class InterceptorT implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("=========到达controller前==============");
        return true;//return true 放行
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("===========经过controller后============");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("=============一切接收后，清理一下============");
    }
}

• 配置spring

<mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/**"/><!--拦截所有请求-->
            <bean class="com.mvc.interceptor.InterceptorT"/>
        </mvc:interceptor>
</mvc:interceptors>

• 测试

@Controller
public class InterceptorController {
    @RequestMapping("/t")
    @ResponseBody
    public String test(){
        System.out.println("来自controller");
        return "来自controller";
    }
}