springboot整合Swagger2之坑

首先引入支持：

            io.springfox
            springfox-swagger2
            2.6.1
        
        
            io.springfox
            springfox-swagger-ui
            2.6.1
         

编写配置文件：

package com.example.demo.configuration;

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

/**
 * Created with LXD
 * author:Luhui
 * qq:729913162
 * Date:2018-06-25
 * Time:10:58
 */
@Configuration
@EnableSwagger2
public class SwaggerConfig {
    @Bean
    public Docket api() {
        return new Docket(DocumentationType.SWAGGER_2)
                .apiInfo(apiInfo())
                .select()
                // 自行修改为自己的包路径
                .apis(RequestHandlerSelectors.basePackage("com.example.demo.controller"))
                .paths(PathSelectors.any())
                .build();
    }

    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                .title("api文档")
                .description("restfun 风格接口")
                //服务条款网址
                //.termsOfServiceUrl("http://blog.csdn.net/forezp")
                .version("1.0")
                //.contact(new Contact("帅呆了", "url", "email"))
                .build();
    }
}

启动SpringBoot:

org.springframework.context.ApplicationContextException: Unable to start reactive web server; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.web.reactive.ReactiveWebServerFactoryConfiguration$EmbeddedNetty': Initialization of bean failed; nested exception is java.lang.NoClassDefFoundError: org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapter
	at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.onRefresh(ReactiveWebServerApplicationContext.java:76) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544) ~[spring-context-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.refresh(ReactiveWebServerApplicationContext.java:61) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at com.example.demo.DemoApplication.main(DemoApplication.java:9) [classes/:na]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.web.reactive.ReactiveWebServerFactoryConfiguration$EmbeddedNetty': Initialization of bean failed; nested exception is java.lang.NoClassDefFoundError: org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapter
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:587) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:501) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:368) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1254) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1103) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:541) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:501) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:204) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.getWebServerFactory(ReactiveWebServerApplicationContext.java:135) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.createWebServer(ReactiveWebServerApplicationContext.java:99) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.onRefresh(ReactiveWebServerApplicationContext.java:73) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	... 8 common frames omitted
Caused by: java.lang.NoClassDefFoundError: org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapter
	at springfox.documentation.spring.web.ObjectMapperConfigurer.postProcessBeforeInitialization(ObjectMapperConfigurer.java:45) ~[springfox-spring-web-2.6.1.jar:2.6.1]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:422) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1698) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:579) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	... 25 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_161]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_161]
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:338) ~[na:1.8.0_161]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_161]
	... 29 common frames omitted 

于是上网查找也没有人遇到过相关错误，百度，谷歌都无解，可以确实这个类确实存在，就在spring-webflux-5.0.6.RELEASE.jar中.

解决方案，将webflux包改为web包，或者再次引入web包：

            org.springframework.boot
            spring-boot-starter-web
         

项目即可成功运行。