欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页

04点睛Spring MVC 4.1-拦截器

程序员文章站 2022-03-10 14:47:37
...

4.1 拦截器

  • 拦截器实现了对每一个请求处理之前和之后进行相关的处理,类似于Servlet的filter;
  • 可以实现HandlerInterceptor接口或者继承HandlerInterceptorAdapter类;
  • 继承HandlerInterceptorAdapter类,因为使用接口要实现接口的所有方法;

4.2 示例

  • 新建拦截器
package com.wisely.interceptors;

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

import org.springframework.stereotype.Service;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

public class DemoInteceptor extends HandlerInterceptorAdapter {
    @Override
    public boolean preHandle(HttpServletRequest request,
            HttpServletResponse response, Object handler) throws Exception {
        System.out.println("request开始前");
        long startTime = System.currentTimeMillis();
        request.setAttribute("startTime", startTime);
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request,
            HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throws Exception {
        System.out.println("request结束后");
        long startTime = (Long) request.getAttribute("startTime");
        request.removeAttribute("startTime");
        long endTime = System.currentTimeMillis();
        request.setAttribute("handlingTime", endTime - startTime);
    }
}
  • 修改配置,注册拦截器
package com.wisely;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.JstlView;
import org.springframework.web.servlet.view.UrlBasedViewResolver;

import com.wisely.interceptors.DemoInteceptor;

@Configuration
@ComponentScan("com.wisely")
@EnableWebMvc
public class DemoMVCConfig extends WebMvcConfigurerAdapter {


    @Bean
    public UrlBasedViewResolver viewResolver(){
        UrlBasedViewResolver resolver = new UrlBasedViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".jsp");
        resolver.setViewClass(JstlView.class);
        return resolver;
    }
    //注册拦截器
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
    registry.addInterceptor(demoInteceptor());
    }
    //自定义拦截器
    @Bean
    public DemoInteceptor demoInteceptor(){
        return new DemoInteceptor();
    }

}
  • 在index.jsp添加代码接受拦截器里放置的handlingTime
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
index.jsp  is here

value from inteceptor 处理耗时:${handlingTime}ms

</body>
</html>

输出结果

 04点睛Spring MVC 4.1-拦截器
            
    
    博客分类: 点睛Spring MVC 4.1  

 

 

新书推荐《JavaEE开发的颠覆者: Spring Boot实战》,涵盖Spring 4.x、Spring MVC 4.x、Spring Boot企业开发实战。

 

京东地址:http://item.jd.com/11894632.html

当当地址:http://product.dangdang.com/23926195.html

亚马逊地址:http://www.amazon.cn/图书/dp/B01D5ZBFUK/ref=zg_bsnr_663834051_6 

淘宝地址:https://item.taobao.com/item.htm?id=528426235744&ns=1&abbucket=8#detail

 

 

 

或自己在京东、淘宝、亚马逊、当当、互动出版社搜索自选。

 


04点睛Spring MVC 4.1-拦截器
            
    
    博客分类: 点睛Spring MVC 4.1