spring boot 2.6.x 集成swagger3 启动报错解决方案

spring boot

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.6.3</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

swagger starter

<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-boot-starter</artifactId>
    <version>3.0.0</version>
</dependency>

swagger 配置类

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.oas.annotations.EnableOpenApi;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.Contact;
import springfox.documentation.service.VendorExtension;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;

import java.util.ArrayList;

@Configuration
// swagger3 更新了注解
@EnableOpenApi
public class SwaggerConfig {
    //配置Swagger的Docket的bean实例
    @Bean
    public Docket docket() {
        return new Docket(DocumentationType.SWAGGER_2)
                .apiInfo(apiInfo());//配置Swagger信息
    }

    //配置Swagger信息
    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                //设置文档标题(API名称)
                .title("title")
                //文档描述
                .description("desc")
                //版本号
                .version("1.0")
                .build();
    }

}

解决启动报错

import lombok.extern.slf4j.Slf4j;
import org.apache.dubbo.common.utils.ReflectUtils;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping;
import springfox.documentation.spring.web.plugins.WebFluxRequestHandlerProvider;
import springfox.documentation.spring.web.plugins.WebMvcRequestHandlerProvider;

import java.lang.reflect.Field;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;

/**
 * 自定义BeanPostProcessor
 */
@Configuration
@Slf4j
public class MyBeanPostProcessor implements BeanPostProcessor {
    @Autowired
    private DefaultListableBeanFactory defaultListableBeanFactory;

    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        return bean;
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        handleWebMvcRequestHandlerProvider(beanName, bean);
        return bean;
    }

    private void handleWebMvcRequestHandlerProvider(String beanName, Object bean) {
        // 处理swagger 在spring boot2.6以上不可用的问题
        boolean modify = (bean instanceof WebMvcRequestHandlerProvider ||
                bean instanceof WebFluxRequestHandlerProvider) &&
                defaultListableBeanFactory.containsBean(beanName);
        if (modify) {
            // 修改属性
            try {
                Field handlerMappingsField = bean.getClass().getDeclaredField("handlerMappings");
                ReflectUtils.makeAccessible(handlerMappingsField);
                List<RequestMappingInfoHandlerMapping> handlerMappings =
                        (List<RequestMappingInfoHandlerMapping>) handlerMappingsField.get(bean);
                List<RequestMappingInfoHandlerMapping> tmpHandlerMappings = handlerMappings.stream()
                        .filter(mapping -> Objects.isNull(mapping.getPatternParser())).collect(Collectors.toList());
                handlerMappings.clear();
                handlerMappings.addAll(tmpHandlerMappings);
            } catch (Exception e) {
                log.warn("修改WebMvcRequestHandlerProvider的属性：handlerMappings出错，可能导致swagger不可用", e);
            }
        }
    }
}

启动后访问地址：http://localhost:8080/swagger-ui/index.html