Failed to start bean ‘documentationPluginsBootstrapper’； nested exception is java.lang.NullPointer

Failed to start bean ‘documentationPluginsBootstrapper’; nested exception is java.lang.NullPointerException

The reason for the error is that the versions of swagger and springboot do not match

This is because the path matching used by Springfox is based on AntPathMatcher, while Spring Boot 2.6.X uses PathPatternMatcher.

Solution

spring:
  mvc:
    pathmatch:
      matching-strategy: ant_path_matcher

add dependencies

<dependency>
   <groupId>com.google.guava</groupId>
   <artifactId>guava</artifactId>
   <version>28.2-android</version>
</dependency>

I read this blogger's article