《springboot实战》第五章 springboot 拦截器

阳光穿透心脏的1/2处 2023-09-25 21:43 39阅读 0赞

## 系列文章目录 ##

[第一章 SpringBoot起步][SpringBoot]  
[第二章 springboot 配置文件、多环境配置、运行优先级][springboot]  
[第三章 springboot 统一日志][springboot 1]  
[第四章 SpringBoot加载静态文件资源][SpringBoot 1]  
[第五章 springboot 拦截器][springboot 2]  
[第六章 实现自定义全局异常处理][Link 1]  
[第七章 springboot 数据库应用][springboot 3]  
[第八章 springboot 整合Druid][springboot _Druid]  
[第九章 springboot 整合MyBatis - xml、注解篇][springboot _MyBatis - xml]  
[第十一章 整合Mybatis plus][_Mybatis plus]  
[第十二章 SpringBoot整合swagger-bootstrap-ui][SpringBoot_swagger-bootstrap-ui]

--------------------

#### 文章目录 ####

*  系列文章目录
 *  1、前言
 *  2、定义拦截器
 *  3、注册拦截器
 *  4、指定拦截规则

![在这里插入图片描述][a8cf9b3c27114e969796fec68fd375b1.png]

--------------------

## 1、前言 ##

**拦截器的主要作用：登录校验、权限验证、乱码解决、性能监控和异常处理等**

在 Spring Boot 项目中，使用拦截器功能通常需要以下 3 步：

*  定义拦截器
 *  注册拦截器
 *  指定拦截规则

## 2、定义拦截器 ##

HandlerInterceptor 接口中定义以下 3 个方法，如下表。

<table> 
 <thead> 
  <tr> 
   <th>返回值类型</th> 
   <th align="left">方法声明</th> 
   <th align="left">描述</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>boolean</td> 
   <td align="left">preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)</td> 
   <td align="left">preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)</td> 
  </tr> 
  <tr> 
   <td>void</td> 
   <td align="left">postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView)</td> 
   <td align="left">该方法在控制器处理请求方法调用之后、解析视图之前执行，可以通过此方法对请求域中的模型和视图做进一步修改。</td> 
  </tr> 
  <tr> 
   <td>void</td> 
   <td align="left">afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)</td> 
   <td align="left">该方法在视图渲染结束后执行，可以通过此方法实现资源清理、记录日志信息等工作。</td> 
  </tr> 
 </tbody> 
</table>

/**
     * 通用拦截器
     */
    public class CommonInterceptor implements HandlerInterceptor {
        
        @Override
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        
            return true;
        }
    
        @Override
        public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        
    
        }
    
        @Override
        public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        
    
        }
    }

## 3、注册拦截器 ##

创建一个实现了 WebMvcConfigurer 接口的配置类（使用了 @Configuration 注解的类），重写 addInterceptors() 方法

@Configuration
    public class MvcConfig implements WebMvcConfigurer {
        
        /**
         * 注册自定义的拦截器
         * @param registry
         */
        @Override    
        public void addInterceptors(InterceptorRegistry registry) {
        
            registry.addInterceptor(new CommonInterceptor());
            
        }
    }

## 4、指定拦截规则 ##

如果是拦截所有，静态资源也会被拦截

@Configuration
    public class MvcConfig implements WebMvcConfigurer {
        
        /**
         * 注册自定义的拦截器
         * @param registry
         */
        @Override
        public void addInterceptors(InterceptorRegistry registry) {
        
            registry.addInterceptor(new CommonInterceptor()).addPathPatterns("/**")//拦截所有请求
                    .excludePathPatterns("/","/login","*.html","/images/**");//放行的请求
        }
    }

[SpringBoot]: https://blog.csdn.net/s445320/article/details/129921683
[springboot]: https://blog.csdn.net/s445320/article/details/129933138
[springboot 1]: https://blog.csdn.net/s445320/article/details/129949778
[SpringBoot 1]: https://blog.csdn.net/s445320/article/details/129952680
[springboot 2]: https://blog.csdn.net/s445320/article/details/129953402
[Link 1]: https://blog.csdn.net/s445320/article/details/130248527
[springboot 3]: https://blog.csdn.net/s445320/article/details/129958603
[springboot _Druid]: https://blog.csdn.net/s445320/article/details/129989045
[springboot _MyBatis - xml]: https://blog.csdn.net/s445320/article/details/130012383
[_Mybatis plus]: https://blog.csdn.net/s445320/article/details/130130130
[SpringBoot_swagger-bootstrap-ui]: https://blog.csdn.net/s445320/article/details/130419460
[a8cf9b3c27114e969796fec68fd375b1.png]: https://img-blog.csdnimg.cn/a8cf9b3c27114e969796fec68fd375b1.png