springboot 2.6.x整合swagger2 3.0.0报错异常整理及解决办法

目前本版本的springboot是2.6.6，swagger是3.0.0；

1、pom依赖

    org.springframework.boot
    spring-boot-starter-parent
    2.6.6
    




    io.springfox
    springfox-boot-starter
    3.0.0

2、问题1：Failed to start bean ‘documentationPluginsBootstrapper’; nested exception is java.lang.NullPointerException

导致项目无法启动

解决办法：在SwaggerConfig中引入bean

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

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

3、问题2：工程能启动了，但是无法访问swagger接口

在application.yml配置文件中增加如下配置：

spring:
  mvc:
    pathmatch:
      matching-strategy: ANT_PATH_MATCHER