Spring Boot整合Knife4j-3.0.3

Spring Boot整合Knife4j-3.0.3

1. 引言

前面我写过一篇关于整合knife4j的文档 Spring Boot整合Knife4j-2.0.7
最近我引入redission的时候莫名其妙的抛出异常：

Failed to start bean 'documentationPluginsBootstrapper'; nested exception is java.lang.NullPointerException

原因：

springboot的版本和Springfox-Swagge的版本不兼容

2. 快捷的解决方案

2.1 修改knife4j的依赖

knife4j依赖

<dependency>
    <groupId>com.github.xiaoymin</groupId>
    <artifactId>knife4j-spring-boot-starter</artifactId>
    <version>3.0.3</version>
</dependency>

springboot版本

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.7.5</version>
</parent>

2.2 application.yml增加配置

spring:
  mvc:
    pathmatch:
      matching-strategy: ANT_PATH_MATCHER

这个不能少，否则接口html页面显示不出来

3.3 SwaggerConfig配置如下

package com.jiayuan.common.config;

import com.github.xiaoymin.knife4j.spring.annotations.EnableKnife4j;
import com.github.xiaoymin.knife4j.spring.extension.OpenApiExtensionResolver;
import com.jiayuan.common.constant.Constant;
import io.swagger.annotations.ApiOperation;
import lombok.AllArgsConstructor;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.util.ReflectionUtils;
import org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.ApiKey;
import springfox.documentation.service.SecurityScheme;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.spring.web.plugins.WebFluxRequestHandlerProvider;
import springfox.documentation.spring.web.plugins.WebMvcRequestHandlerProvider;
import springfox.documentation.swagger2.annotations.EnableSwagger2;
import springfox.documentation.swagger2.annotations.EnableSwagger2WebMvc;

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

import static com.google.common.collect.Lists.newArrayList;

/**
 * Swagger配置
 *
 * @author xmc
 */
@Configuration
@EnableSwagger2
@AllArgsConstructor
@EnableKnife4j
public class SwaggerConfig {
    private final OpenApiExtensionResolver openApiExtensionResolver;

    @Bean
    public Docket createRestApi() {
        return new Docket(DocumentationType.SWAGGER_2)
                .apiInfo(apiInfo())
                .select()
                //加了ApiOperation注解的类，生成接口文档
                .apis(RequestHandlerSelectors.withMethodAnnotation(ApiOperation.class))
                //包下的类，生成接口文档
                //.apis(RequestHandlerSelectors.basePackage("com.jiayuan.modules.job.controller"))
                .paths(PathSelectors.any())
                .build()
                .extensions(openApiExtensionResolver.buildExtensions("criticalVal-management-system"))
                .directModelSubstitute(java.util.Date.class, String.class)
                .securitySchemes(security());
    }

    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                .title("危急值管理系统")
                .description("cvms-api文档")
                .version("1.0")
                .build();
    }

    private List<SecurityScheme> security() {
        return newArrayList(
                new ApiKey(Constant.TOKEN_HEADER, Constant.TOKEN_HEADER, "header")
        );
    }

    @Bean
    public static BeanPostProcessor springfoxHandlerProviderBeanPostProcessor() {
        return new BeanPostProcessor() {

            @Override
            public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
                if (bean instanceof WebMvcRequestHandlerProvider || bean instanceof WebFluxRequestHandlerProvider) {
                    customizeSpringfoxHandlerMappings(getHandlerMappings(bean));
                }
                return bean;
            }

            private <T extends RequestMappingInfoHandlerMapping> void customizeSpringfoxHandlerMappings(List<T> mappings) {
                List<T> copy = mappings.stream()
                        .filter(mapping -> mapping.getPatternParser() == null)
                        .collect(Collectors.toList());
                mappings.clear();
                mappings.addAll(copy);
            }

            @SuppressWarnings("unchecked")
            private List<RequestMappingInfoHandlerMapping> getHandlerMappings(Object bean) {
                try {
                    Field field = ReflectionUtils.findField(bean.getClass(), "handlerMappings");
                    field.setAccessible(true);
                    return (List<RequestMappingInfoHandlerMapping>) field.get(bean);
                } catch (IllegalArgumentException | IllegalAccessException e) {
                    throw new IllegalStateException(e);
                }
            }
        };
    }


}