报错信息

org.springframework.context.ApplicationContextException: Failed to start bean 'documentationPluginsBootstrapper'; nested exception is java.lang.NullPointerException

环境依赖

• springboot 2.6.3
• springfox 3.0.0
• jdk 1.8

Springfox 设置 Spring MVC 的路径匹配策略是 ant-path-matcher，而 Spring Boot 2.6.x版本的默认匹配策略是 path-pattern-matcher，这就造成了上面的报错

• 尝试使用 spring.mvc.pathmatch.matching-strategy: ant_path_matcher，未生效。这是网上大多数的解决办法

我的解决办法

参考github

方法1

spring:
  mvc:
    pathmatch:
      matching-strategy: ANT_PATH_MATCHER

添加依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

注入bean

@Bean
public WebMvcEndpointHandlerMapping webEndpointServletHandlerMapping(
    WebEndpointsSupplier webEndpointsSupplier, ServletEndpointsSupplier servletEndpointsSupplier,
    ControllerEndpointsSupplier controllerEndpointsSupplier, EndpointMediaTypes endpointMediaTypes,
    CorsEndpointProperties corsProperties, WebEndpointProperties webEndpointProperties, Environment environment) {
    List<ExposableEndpoint<?>> allEndpoints = new ArrayList<>();
    Collection<ExposableWebEndpoint> webEndpoints = webEndpointsSupplier.getEndpoints();
    allEndpoints.addAll(webEndpoints);
    allEndpoints.addAll(servletEndpointsSupplier.getEndpoints());
    allEndpoints.addAll(controllerEndpointsSupplier.getEndpoints());
    String basePath = webEndpointProperties.getBasePath();
    EndpointMapping endpointMapping = new EndpointMapping(basePath);
    boolean shouldRegisterLinksMapping = webEndpointProperties.getDiscovery().isEnabled() &&
            (org.springframework.util.StringUtils.hasText(basePath) || ManagementPortType.get(environment).equals(ManagementPortType.DIFFERENT));
    return new WebMvcEndpointHandlerMapping(endpointMapping, webEndpoints, endpointMediaTypes, corsProperties.toCorsConfiguration(), new EndpointLinksResolver(allEndpoints, basePath), shouldRegisterLinksMapping, null);
}

方案2

@Bean
public static BeanPostProcessor springfoxHandlerProviderBeanPostProcessor() {
    return new BeanPostProcessor() {

        @Override
        public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
            if (bean instanceof WebMvcRequestHandlerProvider || bean instanceof WebFluxRequestHandlerProvider) {
                customizeSpringfoxHandlerMappings(getHandlerMappings(bean));
            }
            return bean;
        }

        private <T extends RequestMappingInfoHandlerMapping> void customizeSpringfoxHandlerMappings(List<T> mappings) {
            List<T> copy = mappings.stream()
                    .filter(mapping -> mapping.getPatternParser() == null)
                    .collect(Collectors.toList());
            mappings.clear();
            mappings.addAll(copy);
        }

        @SuppressWarnings("unchecked")
        private List<RequestMappingInfoHandlerMapping> getHandlerMappings(Object bean) {
            try {
                Field field = ReflectionUtils.findField(bean.getClass(), "handlerMappings");
                field.setAccessible(true);
                return (List<RequestMappingInfoHandlerMapping>) field.get(bean);
            } catch (IllegalArgumentException | IllegalAccessException e) {
                throw new IllegalStateException(e);
            }
        }
    };
}

写在最后

直接使用方法二即可， 方法一是我最开始的解决办法

原创不易，如果有帮助到你，请点个赞再离开吧 ！