解决Spring Boot 拦截器注入service为空的问题

矫情吗；* 2022-06-10 03:58 756阅读 0赞

# 解决Spring Boot 拦截器注入service为空的问题 #

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## 1.需要在拦截器上加@Component ##

@Component
    public class MyInterceptor implements HandlerInterceptor { 
        //想要注入的类
        @Autowired
        UserService userService;
    
        @Override
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    
            System.out.println("request before 拦截");
            return true;
    
        }
    
        @Override
        public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
            System.out.println("post 拦截");
    
        }
    
        @Override
        public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
            System.out.println("after 拦截");
        }
    }

## 2.进行拦截器配置 ##

@Configuration
    public class MyWebAppConfigurer extends WebMvcConfigurerAdapter { 
    
        //关键，将拦截器作为bean写入配置中
        @Bean
        public MyInterceptor myInterceptor(){
            return new MyInterceptor();
        }
    
        @Override
        public void addInterceptors(InterceptorRegistry registry) {
            //多个拦截器组成一个拦截器链
            // addPathPatterns用于添加拦截规则
            // excludePathPatterns用户排除拦截
            registry.addInterceptor(myInterceptor()).addPathPatterns("/**"); //对来自/** 全路径请求进行拦截
            super.addInterceptors(registry);
        }
    }

> 这样就可以在拦截器中注入service和其他带有注解的类了，而不会再出现注入的注解为空的情况了，美滋滋(●’◡’●)。