For SpringMVC interceptor

Spring interceptors

• An application of Spring Aop that executes a piece of code to enhance an existing method without modifying the source code.

The sample

• Implement the HandlerInterceptor interface

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

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

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("============= after receiving everything, clean it up ============"); }}Copy the code

• Configure the spring

<mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/ * *"/><! -- Intercept all requests -->
            <bean class="com.mvc.interceptor.InterceptorT"/>
        </mvc:interceptor>
</mvc:interceptors>
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• test

@Controller
public class InterceptorController {
    @RequestMapping("/t")
    @ResponseBody
    public String test(a){
        System.out.println("From the controller");
        return "From the controller"; }}Copy the code