Spring Boot 3中用OpenApi无法打开swagger-ui（白标错误页）求助

针对访问http://localhost:8080/swagger-ui.html出现404错误的问题，结合你的配置信息，给出以下排查和解决步骤：

1. 修正日志配置错误 #

你的application.properties中配置了logging.level.io.springfox=DEBUG，但springdoc-openapi与springfox是完全独立的Swagger实现库，该配置无法输出springdoc的调试信息。请修改为：

logging.level.org.springdoc=DEBUG

修改后重启项目，可查看springdoc相关初始化日志，确认是否存在加载异常。

2. 检查版本兼容性 #

springdoc-openapi-ui:1.6.4仅兼容Spring Boot 2.6.x ~ 2.7.x版本：

• 若使用Spring Boot 3.x及以上，需升级springdoc到v2.x版本（依赖调整为org.springdoc:springdoc-openapi-starter-webmvc-ui）
• 若Spring Boot版本低于2.6.x，需降级springdoc到对应兼容版本

3. 调整Swagger UI访问路径 #

尝试移除application.properties中的springdoc.swagger-ui.path=/swagger-ui.html配置，使用springdoc默认访问路径：

• http://localhost:8080/swagger-ui/index.html
• 或http://localhost:8080/swagger-ui/（注意末尾斜杠）

若需自定义路径，确保配置与访问路径一致，例如：

springdoc.swagger-ui.path=/my-swagger.html

此时访问路径应为http://localhost:8080/my-swagger.html

4. 排查静态资源拦截问题 #

若项目存在自定义WebMvcConfigurer配置，可能拦截了Swagger UI的静态资源，需添加放行规则：

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        // 放行swagger-ui静态资源
        registry.addResourceHandler("/swagger-ui/**")
                .addResourceLocations("classpath:/META-INF/resources/webjars/springdoc-openapi-ui/");
        // 放行openapi描述文件
        registry.addResourceHandler("/v3/api-docs/**")
                .addResourceLocations("classpath:/META-INF/resources/");
    }
}

5. 清理依赖并重新构建 #

依赖包下载不完整可能导致静态资源缺失，执行Maven命令清理并重新构建：

mvn clean install

原始配置信息 #

pom.xml依赖

<dependency>
    <groupId>org.springdoc</groupId>
    <artifactId>springdoc-openapi-ui</artifactId>
    <version>1.6.4</version>
</dependency>

OpenApi配置类

@Configuration
public class OpenApiConfig {

    @Bean
    public OpenAPI customOpenAPI(@Value("${application-description}") String description,
                                 @Value("${application-version}") String version) {
        return new OpenAPI()
                .info(new Info().title("API")
                        .version(version)
                        .description(description)
                        .license(new License().name("API Licence")));
    }
}

application.properties

springdoc.swagger-ui.path=/swagger-ui.html
application-description=API Description
application-version=1.0

logging.level.org.springframework.web=DEBUG
logging.level.io.springfox=DEBUG

报错日志

2023-02-09T08:36:16.593+03:00 DEBUG 20184 --- [nio-8080-exec-4] o.s.web.servlet.DispatcherServlet        : GET "/swagger-ui.html", parameters={}
2023-02-09T08:36:16.594+03:00 DEBUG 20184 --- [nio-8080-exec-4] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped to ResourceHttpRequestHandler [classpath [META-INF/resources/], classpath [resources/], classpath [static/], classpath [public/], ServletContext [/]]
2023-02-09T08:36:16.596+03:00 DEBUG 20184 --- [nio-8080-exec-4] o.s.w.s.r.ResourceHttpRequestHandler     : Resource not found
2023-02-09T08:36:16.596+03:00 DEBUG 20184 --- [nio-8080-exec-4] o.s.web.servlet.DispatcherServlet        : Completed 404 NOT_FOUND
2023-02-09T08:36:16.597+03:00 DEBUG 20184 --- [nio-8080-exec-4] o.s.web.servlet.DispatcherServlet        : "ERROR" dispatch for GET "/error", parameters={}
2023-02-09T08:36:16.597+03:00 DEBUG 20184 --- [nio-8080-exec-4] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped to org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController#errorHtml(HttpServletRequest, HttpServletResponse)
2023-02-09T08:36:16.599+03:00 DEBUG 20184 --- [nio-8080-exec-4] o.s.w.s.v.ContentNegotiatingViewResolver : Selected 'text/html' given [text/html, text/html;q=0.8]
2023-02-09T08:36:16.599+03:00 DEBUG 20184 --- [nio-8080-exec-4] o.s.web.servlet.DispatcherServlet        : Exiting from "ERROR" dispatch, status 404

内容的提问来源于stack exchange，提问作者Sercan Noyan Germiyanoğlu