1本文源码
2GitHub:知了一笑
3https://github.com/cicadasmile/spring-boot-base

一、拦截器简介

1、拦截器定义

拦截器，请求的接口被访问之前，进行拦截然后在之前或之后加入某些操作。拦截是AOP的一种实现策略。 拦截器主要用来按照指定规则拒绝请求。

2、拦截器中应用

1Token令牌验证
2请求数据校验
3用户权限校验
4放行指定接口

二、SpringBoot2.0拦截器用法

1、编写两个拦截器

自定义类实现HandlerInterceptor接口

1）OneInterceptor 拦截器

1import org.slf4j.Logger;
2import org.slf4j.LoggerFactory;
3import org.springframework.web.servlet.HandlerInterceptor;
4import org.springframework.web.servlet.ModelAndView;
5import javax.servlet.http.HttpServletRequest;
6import javax.servlet.http.HttpServletResponse;
7/**
8 * 拦截器一
9 */
10public class OneInterceptor implements HandlerInterceptor {
11 private static final Logger LOGGER
12 = LoggerFactory.getLogger(OneInterceptor.class.getName());
13 @Override
14 public boolean preHandle(HttpServletRequest request,
15 HttpServletResponse response,
16 Object o) throws Exception {
17 String url =String.valueOf(request.getRequestURL()) ;
18 LOGGER.info("1、url=="+url);
19 // 放开拦截
20 return true;
21 }
22 @Override
23 public void postHandle(HttpServletRequest httpServletRequest,
24 HttpServletResponse httpServletResponse,
25 Object o, ModelAndView modelAndView) throws Exception {
26 LOGGER.info("1、postHandle");
27 }
28 @Override
29 public void afterCompletion(HttpServletRequest httpServletRequest,
30 HttpServletResponse httpServletResponse,
31 Object o, Exception e) throws Exception {
32 LOGGER.info("1、afterCompletion");
33 }
34}

2）TwoInterceptor 拦截器

1import org.slf4j.Logger;
2import org.slf4j.LoggerFactory;
3import org.springframework.web.servlet.HandlerInterceptor;
4import org.springframework.web.servlet.ModelAndView;
5import javax.servlet.http.HttpServletRequest;
6import javax.servlet.http.HttpServletResponse;
7/**
8 * 拦截器二
9 */
10public class TwoInterceptor implements HandlerInterceptor {
11 private static final Logger LOGGER
12 = LoggerFactory.getLogger(TwoInterceptor.class.getName());
13 @Override
14 public boolean preHandle(HttpServletRequest request,
15 HttpServletResponse response,
16 Object o) throws Exception {
17 String url =String.valueOf(request.getRequestURL()) ;
18 LOGGER.info("2、url=="+url);
19 // 放开拦截
20 return true;
21 }
22 @Override
23 public void postHandle(HttpServletRequest httpServletRequest,
24 HttpServletResponse httpServletResponse,
25 Object o, ModelAndView modelAndView) throws Exception {
26 LOGGER.info("2、postHandle");
27 }
28 @Override
29 public void afterCompletion(HttpServletRequest httpServletRequest,
30 HttpServletResponse httpServletResponse,
31 Object o, Exception e) throws Exception {
32 LOGGER.info("2、afterCompletion");
33 }
34}

2、Web配置文件中注入拦截器

1import com.boot.intercept.intercept.OneInterceptor;
2import com.boot.intercept.intercept.TwoInterceptor;
3import org.springframework.context.annotation.Configuration;
4import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
5import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
6/**
7 * Web配置文件
8 */
9@Configuration
10public class WebMvcConfig implements WebMvcConfigurer {
11 public void addInterceptors(InterceptorRegistry registry) {
12 // 拦截所有路径
13 // 注册自定义两个拦截器
14 registry.addInterceptor(new OneInterceptor()).addPathPatterns("/**");
15 registry.addInterceptor(new TwoInterceptor()).addPathPatterns("/**");
16 }
17}

3、编写测试接口

1import org.springframework.web.bind.annotation.RequestMapping;
2import org.springframework.web.bind.annotation.RestController;
3@RestController
4public class InterceptController {
5 @RequestMapping("/reqUrl")
6 public String reqUrl (){
7 return "success" ;
8 }
9}

4、访问测试接口

日志输出内容如下

1intercept.OneInterceptor : 1、url==http://127.0.0.1:8005/reqUrl
2intercept.TwoInterceptor : 2、url==http://127.0.0.1:8005/reqUrl
3intercept.TwoInterceptor : 2、postHandle
4intercept.OneInterceptor : 1、postHandle
5intercept.TwoInterceptor : 2、afterCompletion
6intercept.OneInterceptor : 1、afterCompletionla

拦截器的拦截顺序，是按照Web配置文件中注入拦截器的顺序执行的。

三、源代码地址

1GitHub地址：知了一笑
2https://github.com/cicadasmile
3码云地址：知了一笑
4https://gitee.com/cicadasmile