最近在用Springboot2.7整合knife4j-openapi2-spring-boot-starter后,发现无法启动项目直接报错
报错信息
org.springframework.context.ApplicationContextException: Failed to start bean 'documentationPluginsBootstrapper'; nested exception is java.lang.NullPointerException
网上解决办法
当时直接搜索引擎一动,解决办法基本上都是添加一个配置。原因是:Spring Boot 2.6以上引入的新PathPatternParser,需要进行配置,不然整合起来会报错
spring.mvc.pathmatch.matching-strategy=ant-path-matcher
具体问题原因和解决方案
当时以为加上就可以了,结果发现并没有解决问题,问题还是存在,最后网上再次搜索验证,得到的问题原因是和项目引入的其他依赖冲突,当项目当中引入了spring-boot-starter-actuator就会出现这个问题。
可用的解决方案是添加一个bean配置:
@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) {
mappings.removeIf(mapping -> mapping.getPatternParser() != null);
}
@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);
}
}
};
}
最后附上解决资料连接:https://gitee.com/xiaoym/knife4j/issues/I4JT89 (没事多看看issues,大佬云集)