springmvc中实现拦截器

• Interceptor拦截器实现对每一个请求处理前后进行相关的业务，类似于servlet的Filter
• 普通的Bean去继承HandlerInterceptorAdapter或实现HandlerInterceptor来自定义拦截器
• 通过重写WebMvcConfigurerAdapter的addInterceptors方法来注册自定义的拦截器

示例如下：

在“springmvc简单构建一个项目（一）”的基础上增加以下这些：

 

1.自定义拦截器

package com.zgw.springmvc;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

/**
 * 实现HandlerInterceptor接口或继承HandlerInterceptorAdapter
 * 来实现自定义拦截器
 * @author zan
 *
 */
public class InterceptorDemo implements HandlerInterceptor{

	//请求前执行
	@Override
	public boolean preHandle(HttpServletRequest request, 
			HttpServletResponse response, Object handler) throws Exception {
		long startTime = System.currentTimeMillis();
		request.setAttribute("startTime", startTime);
		return true;
	}

	//请求发生后执行
	@Override
	public void postHandle(HttpServletRequest request, 
			HttpServletResponse response, Object handler,
			ModelAndView modelAndView) throws Exception {
		long startTime = (Long) request.getAttribute("startTime");
		request.removeAttribute("startTime");
		long endTime = System.currentTimeMillis();
		System.out.println("本次请求时间为:" + new Long(endTime - startTime)+"ms");
		request.setAttribute("handlingTime", endTime - startTime);
	}

	@Override
	public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
			throws Exception {

	}

}

 2.配置，在MySpringmvcConfig类中添加：

 

/*
	 * 配置拦截器的Bean
	 */
	@Bean
	public InterceptorDemo interceptor() {
		return new InterceptorDemo();
	}

	/*
	 * 重写addInterceptors方法，注册一个拦截器
	 */
	@Override
	public void addInterceptors(InterceptorRegistry registry) {
		registry.addInterceptor(interceptor());
	}

 

3.运行，访问http://localhost:8080/springmvc_withoutwebxml/index,结果如下：