spring boot 3.x版本引入 swagger2启动时报错

一，问题

Spring Boot 3.x版本的项目里，准备引入Swagger2作为接口文档，但是项目启动报错：

java.lang.TypeNotPresentException: Type javax.servlet.http.HttpServletRequest not present
   at java.base/sun.reflect.generics.factory.CoreReflectionFactory.makeNamedType(CoreReflectionFactory.java:117) ~[na:na]
   at java.base/sun.reflect.generics.visitor.Reifier.visitClassTypeSignature(Reifier.java:125) ~[na:na]
   at java.base/sun.reflect.generics.tree.ClassTypeSignature.accept(ClassTypeSignature.java:49) ~[na:na]
   at java.base/sun.reflect.generics.visitor.Reifier.reifyTypeArguments(Reifier.java:68) ~[na:na]
   at java.base/sun.reflect.generics.visitor.Reifier.visitClassTypeSignature(Reifier.java:138) ~[na:na]
   at java.base/sun.reflect.generics.tree.ClassTypeSignature.accept(ClassTypeSignature.java:49) ~[na:na]
   at java.base/sun.reflect.generics.repository.ClassRepository.computeSuperInterfaces(ClassRepository.java:117) ~[na:na]
   at java.base/sun.reflect.generics.repository.ClassRepository.getSuperInterfaces(ClassRepository.java:95) ~[na:na]
   at java.base/java.lang.Class.getGenericInterfaces(Class.java:1211) ~[na:na]
   at org.springframework.core.ResolvableType.getInterfaces(ResolvableType.java:517) ~[spring-core-6.1.8.jar:6.1.8]
   at org.springframework.core.ResolvableType.as(ResolvableType.java:465) ~[spring-core-6.1.8.jar:6.1.8]
   at org.springframework.core.ResolvableType.forClass(ResolvableType.java:1093) ~[spring-core-6.1.8.jar:6.1.8]
   at org.springframework.plugin.core.config.PluginRegistriesBeanDefinitionRegistrar.getTargetType(PluginRegistriesBeanDefinitionRegistrar.java:101) ~[spring-plugin-core-2.0.0.RELEASE.jar:2.0.0.RELEASE]
   at org.springframework.plugin.core.config.PluginRegistriesBeanDefinitionRegistrar.registerBeanDefinitions(PluginRegistriesBeanDefinitionRegistrar.java:71) ~[spring-plugin-core-2.0.0.RELEASE.jar:2.0.0.RELEASE]
   at org.springframework.context.annotation.ImportBeanDefinitionRegistrar.registerBeanDefinitions(ImportBeanDefinitionRegistrar.java:86) ~[spring-context-6.1.8.jar:6.1.8]
   at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.lambda$loadBeanDefinitionsFromRegistrars$1(ConfigurationClassBeanDefinitionReader.java:376) ~[spring-context-6.1.8.jar:6.1.8]
   at java.base/java.util.LinkedHashMap.forEach(LinkedHashMap.java:721) ~[na:na]
   at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsFromRegistrars(ConfigurationClassBeanDefinitionReader.java:375) ~[spring-context-6.1.8.jar:6.1.8]
   at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForConfigurationClass(ConfigurationClassBeanDefinitionReader.java:148) ~[spring-context-6.1.8.jar:6.1.8]
   at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitions(ConfigurationClassBeanDefinitionReader.java:120) ~[spring-context-6.1.8.jar:6.1.8]
   at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:429) ~[spring-context-6.1.8.jar:6.1.8]
   at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:290) ~[spring-context-6.1.8.jar:6.1.8]
   at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:349) ~[spring-context-6.1.8.jar:6.1.8]
   at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:118) ~[spring-context-6.1.8.jar:6.1.8]
   at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:788) ~[spring-context-6.1.8.jar:6.1.8]
   at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:606) ~[spring-context-6.1.8.jar:6.1.8]
   at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[spring-boot-3.3.0.jar:3.3.0]
   at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[spring-boot-3.3.0.jar:3.3.0]
   at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:456) ~[spring-boot-3.3.0.jar:3.3.0]
   at org.springframework.boot.SpringApplication.run(SpringApplication.java:335) ~[spring-boot-3.3.0.jar:3.3.0]
   at org.springframework.boot.SpringApplication.run(SpringApplication.java:1363) ~[spring-boot-3.3.0.jar:3.3.0]
   at org.springframework.boot.SpringApplication.run(SpringApplication.java:1352) ~[spring-boot-3.3.0.jar:3.3.0]
   at com.xgd.demo.SpringBootDemoApplication.main(SpringBootDemoApplication.java:19) ~[classes/:na]
Caused by: java.lang.ClassNotFoundException: javax.servlet.http.HttpServletRequest
   at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[na:na]
   at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188) ~[na:na]
   at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[na:na]
   at java.base/java.lang.Class.forName0(Native Method) ~[na:na]
   at java.base/java.lang.Class.forName(Class.java:467) ~[na:na]
   at java.base/sun.reflect.generics.factory.CoreReflectionFactory.makeNamedType(CoreReflectionFactory.java:114) ~[na:na]
   ... 32 common frames omitted

二，描述

当前的配置如下：

1，pom里的swagger配置

<!-- swagger -->
<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger2</artifactId>
    <version>3.0.0</version>
    <scope>compile</scope>
    <exclusions>
       <exclusion>
          <groupId>io.swagger</groupId>
          <artifactId>swagger-models</artifactId>
       </exclusion>
       <exclusion>
          <groupId>io.swagger</groupId>
          <artifactId>swagger-annotations</artifactId>
       </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger-ui</artifactId>
    <version>3.0.0</version>
    <scope>compile</scope>
</dependency>
<!-- 引入1.5.22及以上版本的swagger组件，以解决example默认解析报错（NumberFormatException）的问题 -->
<dependency>
    <groupId>io.swagger</groupId>
    <artifactId>swagger-models</artifactId>
    <version>1.5.22</version>
</dependency>
<dependency>
    <groupId>io.swagger</groupId>
    <artifactId>swagger-annotations</artifactId>
    <version>1.5.22</version>
</dependency>

Spring Boot版本是3.3.0

2，swagger配置

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Profile;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

@Configuration
@Profile("dev")
@EnableSwagger2
public class SwaggerConfig {
    @Bean
    public Docket createApi() {
        return new Docket(DocumentationType.SWAGGER_2)
            .select()
            .apis(RequestHandlerSelectors.basePackage("com.xxx.demo"))
            .paths(PathSelectors.any())
            .build();
    }
}

然后启动报错！

原因是HttpServletRequest的包路径有问题，在SpringBoot 3 之后已经不在javax.servlet 下了，而是移到了jakarta.servlet包下面，所以就会运行报错。

注意：如果你用的是Spring Boot 2.x 版本，上面配置就没有问题。

三，解决

已知是因为HttpServletRequest包路径不对，那么就针对这个修改pom引入就好了。

在pom文件后面加上下面配置

<!-- 升級到Spring Boot 3.x之后，需要从Springfox迁移到SpringDoc，Springfox已经很久没有维护了，不兼容Spring Boot 3.x -->
<dependency>
    <groupId>org.springdoc</groupId>
    <artifactId>springdoc-openapi-starter-webmvc-ui</artifactId>
    <version>2.3.0</version>
</dependency>
<dependency>
    <groupId>org.springdoc</groupId>
    <artifactId>springdoc-openapi-starter-webmvc-api</artifactId>
    <version>2.3.0</version>
</dependency>

swagger配置

import io.swagger.v3.oas.models.OpenAPI;
import io.swagger.v3.oas.models.info.Info;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Profile;

@Configuration
@Profile("dev")
public class SwaggerConfig {
    @Bean
    public OpenAPI openApi() {
       return new OpenAPI().info(new Info().title("demo").description("demo").version("1.0"));
    }
}

接口上引用如下