java.lang.ClassNotFoundException:handlerMapping意味着您在pom.xml中缺少了一个依赖项，确切地说，您缺少了spring-webmvc依赖项。
当您使用Spring Boot时，只需将此依赖项添加到您的pom：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

仔细检查任何其他可能丢失的依赖项。如果您有任何问题，请在这里发布您的pom.xml，我们可以找到丢失的依赖项。

请尝试以下代码

@Configuration
public class SwaggerConfig implements WebMvcConfigurer {    
@Override
        public void addResourceHandlers(ResourceHandlerRegistry registry) {
            registry.addResourceHandler("/api/swagger-ui.html**").addResourceLocations("classpath:/META-INF/resources/swagger-ui.html");
            registry.addResourceHandler("/api/webjars/**").addResourceLocations("classpath:/META-INF/resources/webjars/");
        }

        @Bean
        public Docket api() {
            return new Docket(DocumentationType.SWAGGER_2).select()
                    .apis(RequestHandlerSelectors.basePackage("com.org.v1")).paths(PathSelectors.any())
                    .build().apiInfo(apiInfo());
        }

        private ApiInfo apiInfo() {
            return new ApiInfo("Service Name", "API Description", "API", "Terms of service",
                    new Contact("name", "webaddress", "email"), "License of API", "API license URL",
                    Collections.emptyList());
        }

Swagger依赖项已用于版本2.7.0

<dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>${swagger.version}</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>${swagger.version}</version>
        </dependency>

@EnableSwagger2可以位于同一位置或主应用程序类

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>3.0.1</version>
    <relativePath /> <!-- lookup parent from repository -->
</parent>
<groupId>com.user-registration</groupId>
<artifactId>registration</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>registration</name>
<description>Registration</description>
<properties>
    <java.version>17</java.version>
</properties>
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-swagger2</artifactId>
        <version>2.6.0</version>
    </dependency>

    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-swagger-ui</artifactId>
        <version>2.6.0</version>
    </dependency>

    <!-- 
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-security</artifactId>
    </dependency>
    
    -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>

    <!--        <dependency>
        <groupId>org.thymeleaf.extras</groupId>
        <artifactId>thymeleaf-extras-springsecurity6</artifactId>
    </dependency>
-->

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>com.mysql</groupId>
        <artifactId>mysql-connector-j</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.20</version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <!-- 
    <dependency>
        <groupId>org.springframework.security</groupId>
        <artifactId>spring-security-test</artifactId>
        <scope>test</scope>
    </dependency>
    -->
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>