Swagger2：无法内省类 [springfox.documentation.swagger2.configuration.Swagger2DocumentationConfiguration]

Question

我正在尝试在我的项目中使用 swagger2，但出现错误。

“java.lang.IllegalStateException：无法从 ClassLoader [jdk.internal.loader.ClassLoaders$AppClassLoader@16f65612] 内省 Class [springfox.documentation.swagger2.configuration.Swagger2DocumentationConfiguration]”

//Spring Boot version: 2.1.9
//Swagger2: 2.9.2
//java: 11

package path.to.package;

import static springfox.documentation.builders.PathSelectors.regex;

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

@Configuration
@EnableSwagger2
public class SwaggerConfig {

  @Bean
  public Docket OrganizationApi() {
    return new Docket(DocumentationType.SWAGGER_2)
        .select()
        .apis(RequestHandlerSelectors.basePackage("path.to.package"))
        .paths(regex("/api/.*"))
        .build();
  }

}


<!-- https://mvnrepository.com/artifact/io.springfox/springfox-swagger2 -->
<dependency>
  <groupId>io.springfox</groupId>
  <artifactId>springfox-swagger2</artifactId>
  <version>2.9.2</version>
</dependency>

<!-- https://mvnrepository.com/artifact/io.springfox/springfox-swagger-ui -->
<dependency>
  <groupId>io.springfox</groupId>
  <artifactId>springfox-swagger-ui</artifactId>
  <version>2.9.2</version>
</dependency>

完整的堆栈跟踪：

    at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:507)
    at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:404)
    at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:389)
    at org.springframework.util.ReflectionUtils.getUniqueDeclaredMethods(ReflectionUtils.java:447)
    at java.base/java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1705)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.getTypeForFactoryMethod(AbstractAutowireCapableBeanFactory.java:738)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineTargetType(AbstractAutowireCapableBeanFactory.java:679)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:647)
    at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1518)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:513)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:483)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:604)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:596)
    at org.springframework.context.support.AbstractApplicationContext.getBeansOfType(AbstractApplicationContext.java:1226)
    at org.springframework.boot.SpringApplication.getExitCodeFromMappedException(SpringApplication.java:866)
    at org.springframework.boot.SpringApplication.getExitCodeFromException(SpringApplication.java:854)
    at org.springframework.boot.SpringApplication.handleExitCode(SpringApplication.java:841)
    at org.springframework.boot.SpringApplication.handleRunFailure(SpringApplication.java:792)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:322)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1204)
    at com.path.to.package.Application.main(Application.java:25)
Caused by: java.lang.NoClassDefFoundError: org/springframework/web/servlet/HandlerMapping
    at java.base/java.lang.Class.getDeclaredMethods0(Native Method)
    at java.base/java.lang.Class.privateGetDeclaredMethods(Class.java:3167)
    at java.base/java.lang.Class.getDeclaredMethods(Class.java:2310)
    at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:489)
    ... 21 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.springframework.web.servlet.HandlerMapping
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    ... 25 common frames omitted

Answer 1

java.lang.ClassNotFoundException: org.springframework.web.servlet.HandlerMapping 意味着您在 pom.xml 中缺少依赖项，准确地说，您缺少 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 中：

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

仔细检查可能丢失的任何其他依赖项。如果您有任何问题，请在此处发布您的 pom.xml，我们可以找到丢失的。

Answer 2

请尝试下面的代码

@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 依赖已在 2.7.0 版本中使用

<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