springboot2集成knife4j（swagger3）

• springboot2集成knife4j（swagger3）
  • 环境说明
  • 集成knife4j
    • 第一步：引入依赖
    • 第二步：编写配置类
    • 第三步：放行相关资源 & 保证启动了knife4j
    • 第四步：测试一下
      • 第一小步：编写controller
      • 第二小步：启动项目，访问api文档
  • 相关资料

环境说明

• springboot：2.6.4
• knife4j-spring-boot-starter：3.0.3

集成knife4j

第一步：引入依赖

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

第二步：编写配置类

提示：可以借助配置文件，进一步改造

import com.fasterxml.jackson.databind.introspect.BeanPropertyDefinition;
import com.github.xiaoymin.knife4j.core.model.MarkdownProperty;
import com.github.xiaoymin.knife4j.spring.extension.OpenApiExtensionResolver;
import com.ideaaedi.demo.support.EnumDescriptor;
import io.swagger.annotations.ApiModelProperty;
import io.swagger.annotations.ApiParam;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.reflect.FieldUtils;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.lang.NonNull;
import org.springframework.lang.Nullable;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Controller;
import org.springframework.util.CollectionUtils;
import org.springframework.util.ReflectionUtils;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.ModelSpecificationBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.PropertySpecificationBuilder;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.builders.RequestParameterBuilder;
import springfox.documentation.schema.ScalarType;
import springfox.documentation.service.ApiKey;
import springfox.documentation.service.AuthorizationScope;
import springfox.documentation.service.Contact;
import springfox.documentation.service.SecurityReference;
import springfox.documentation.service.SecurityScheme;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spi.schema.ModelPropertyBuilderPlugin;
import springfox.documentation.spi.schema.contexts.ModelPropertyContext;
import springfox.documentation.spi.service.ParameterBuilderPlugin;
import springfox.documentation.spi.service.contexts.ParameterContext;
import springfox.documentation.spi.service.contexts.SecurityContext;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

import javax.annotation.Resource;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
import java.util.stream.Collectors;

/**
 * Knife4j配置
 *
 * @author <font size = "20" color = "#3CAA3C"><a href="https://gitee.com/JustryDeng">JustryDeng</a></font> <img
 * src="https://gitee.com/JustryDeng/shared-files/raw/master/JustryDeng/avatar.jpg" />
 * @since 1.0.0
 */
@Slf4j
@Configuration
@EnableSwagger2
public class Knife4jConfig implements WebMvcConfigurer {
    
    /** 对于管控了权限的应用，应放行以下资源 */
    public static String[] RESOURCE_URLS = new String[]{"/webjars/**", "/swagger**", "/v3/api-docs", "/doc.html"};
    
    @Value("${spring.application.name:default}")
    private String applicationName;
    
    @Resource
    private OpenApiExtensionResolver openApiExtensionResolver;
    
    @Bean
    public Docket docket() {
        // 指定使用Swagger2规范
        Docket docket = new Docket(DocumentationType.OAS_30)
                .apiInfo(new ApiInfoBuilder()
                        // 简介(支持Markdown语法)
                        .description("# 我是API简介")
                        // 服务地址
                        .termsOfServiceUrl("http://local.idea-aedi.com/")
                        // 作者及联系信息
                        .contact(new Contact("JustryDeng", "https://gitee.com/JustryDeng", "13548417409@163.com"))
                        // api版本
                        .version("1.0.0")
                        .build())
                .extensions(openApiExtensionResolver.buildExtensions(applicationName))
                //分组名称(微服务项目可以用微服务名分组)
                .groupName(applicationName)
                .select()
                // 定位api
                .apis(
                        RequestHandlerSelectors.basePackage(getProjectBasePackage())
                                .and(RequestHandlerSelectors.withClassAnnotation(RestController.class)
                                        .or(RequestHandlerSelectors.withClassAnnotation(Controller.class))
                                )
                )
                .paths(PathSelectors.any())
                .build();
    
        docket.securitySchemes(securitySchemes()).securityContexts(securityContexts());
        
        // 自定义文档解析
        try {
            Field markdownPropertiesField = FieldUtils.getDeclaredField(OpenApiExtensionResolver.class,
                    "markdownProperties", true);
            List<MarkdownProperty> markdownProperties = (List<MarkdownProperty>)markdownPropertiesField.get(openApiExtensionResolver);
            if (!CollectionUtils.isEmpty(markdownProperties)) {
                for (MarkdownProperty markdownProperty : markdownProperties) {
                    docket.extensions(openApiExtensionResolver.buildExtensions(markdownProperty.getGroup()));
                }
            }
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
        
        return docket;
    }
    
    private List<SecurityScheme> securitySchemes() {
        // 设置请求头信息
        List<SecurityScheme> result = new ArrayList<>();
        // 第一个参数name，自定义即可。 在配置securityContexts时，通过此name对应到apiKey即可
        // 第二个参数，header name自定义即可。 如：JWT_TOKEN_KEY=Auth-Token，然后在代码里request.getHeader(JWT_TOKEN_KEY)取值
        String JWT_TOKEN_KEY="Auth-Token";
        ApiKey apiKey = new ApiKey("JustryDengApiKey", JWT_TOKEN_KEY, "header");
        result.add(apiKey);
        return result;
    }
    
    private List<SecurityContext> securityContexts() {
        // 设置需要登录认证的路径
        List<SecurityContext> result = new ArrayList<>();
        List<SecurityReference> securityReferences = defaultAuth();
        result.add(
                SecurityContext.builder().securityReferences(securityReferences).forPaths(
                        // 当直接使用swagger文档发送请求时，这些api需要满足securityReferences认证要求
                        PathSelectors.regex("/.*")
                                .and(
                                        // 当直接使用swagger文档发送请求时，这些api不需要满足securityReferences认证要求. '.*'表示匹配所有
                                        PathSelectors.regex("/hello.*").or(PathSelectors.regex("/hi.*"))
                                                .negate()
                                )
                ).build()
        );
        return result;
    }
    
    private List<SecurityReference> defaultAuth() {
        List<SecurityReference> result = new ArrayList<>();
        AuthorizationScope authorizationScope = new AuthorizationScope("global", "accessEverything");
        AuthorizationScope[] authorizationScopes = new AuthorizationScope[1];
        authorizationScopes[0] = authorizationScope;
        // 这里指定使用哪个apiKey进行认证鉴权. 这里指定使用上面名为JustryDengApiKey的apiKey
        result.add(new SecurityReference("JustryDengApiKey", authorizationScopes));
        return result;
    }
    
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("doc.html").addResourceLocations("classpath:/META-INF/resources/");
        registry.addResourceHandler("/webjars/**").addResourceLocations("classpath:/META-INF/resources/webjars/");
    }
    
    /**
     * 获取项目包前缀
     */
    private String getProjectBasePackage() {
        String projectBasePackage;
        String currPackageName = this.getClass().getPackage().getName();
        String[] packageItemArr = currPackageName.split("\\.");
        if (packageItemArr.length > 3) {
            projectBasePackage = String.join(".", packageItemArr[0], packageItemArr[1], packageItemArr[2]);
        } else {
            projectBasePackage = currPackageName;
        }
        log.info("Base package to scan api is -> {}", projectBasePackage);
        return projectBasePackage;
    }
    
    /**
     * 显示自定义枚举类型注释
     * <p>
     * <br/> 参考<a
     * href="https://blog.gelu.me/2021/Knife4j-Swagger%E8%87%AA%E5%AE%9A%E4%B9%89%E6%9E%9A%E4%B8%BE%E7%B1%BB%E5%9E%8B
     * /">here</a>
     */
    @Component
    @SuppressWarnings("unchecked")
    public static class Knife4jSwaggerEnumPlugin implements ModelPropertyBuilderPlugin, ParameterBuilderPlugin {
        
        private static final Field parameterDescriptionField;
        
        private static final Field modelPropertyBuilderDescriptionField;
        
        
        static {
            parameterDescriptionField = ReflectionUtils.findField(RequestParameterBuilder.class, "description");
            Objects.requireNonNull(parameterDescriptionField, "parameterDescriptionField should noe be null.");
            ReflectionUtils.makeAccessible(parameterDescriptionField);
            
            modelPropertyBuilderDescriptionField = ReflectionUtils.findField(PropertySpecificationBuilder.class, "description");
            Objects.requireNonNull(modelPropertyBuilderDescriptionField, "ModelPropertyBuilder_descriptionField should noe be null.");
            ReflectionUtils.makeAccessible(modelPropertyBuilderDescriptionField);
        }
        
        /**
         * {@link ApiModelProperty}相关
         * <p>
         * 主要处理枚举对象直接作为方法参数的内部字段的情况. 如：
         * <pre>
         *  &nbsp;  @Data
         *  &nbsp;  public class LoginTokenRespVO {
         *  &nbsp;
         *  &nbsp;      @ApiModelProperty("用户类型")
         *  &nbsp;      private UserTypeEnum userType;
         *  &nbsp;  }
         * </pre>
         */
        @Override
        public void apply(ModelPropertyContext context) {
            Optional<BeanPropertyDefinition> optional = context.getBeanPropertyDefinition();
            if (!optional.isPresent()) {
                return;
            }
            // 对应被@ApiModelProperty标注的字段
            BeanPropertyDefinition beanPropertyDefinition = optional.get();
            Class<?> fieldType = beanPropertyDefinition.getField().getRawType();
            if (!Enum.class.isAssignableFrom(fieldType)) {
                return;
            }
            Class<Enum<?>> enumType = (Class<Enum<?>>) fieldType;
            Enum<?>[] enumConstants = enumType.getEnumConstants();
            PropertySpecificationBuilder modelPropertyBuilder = context.getSpecificationBuilder();
            Object oldValue = ReflectionUtils.getField(modelPropertyBuilderDescriptionField, modelPropertyBuilder);
            // 解析枚举
            List<String> enumDescList =
                    Arrays.stream(enumConstants).map(this::obtainEnumDescription).collect(Collectors.toList());
            modelPropertyBuilder.description((oldValue == null ? "" : oldValue) + buildHtmlUnOrderList(enumDescList))
                    .type(new ModelSpecificationBuilder().scalarModel(ScalarType.UUID).build());
        }
        
        /**
         * {@link ApiParam}、{@link io.swagger.v3.oas.annotations.Parameter}相关.
         * <p> 主要处理：枚举对象直接作为方法参数的情况. 如：
         * <pre>
         *  &nbsp;  @PostMapping("/test1")
         *  &nbsp;  @ApiOperation(value = "测试1")
         *  &nbsp;  public void test1(@ApiParam(value = "用户类型", required = true) UserTypeEnum userTypeEnum)
         * </pre>
         */
        @Override
        public void apply(ParameterContext context) {
            Class<?> type = context.resolvedMethodParameter().getParameterType().getErasedType();
            RequestParameterBuilder parameterBuilder = context.requestParameterBuilder();
            if (!Enum.class.isAssignableFrom(type)) {
                return;
            }
            Class<Enum<?>> enumType = (Class<Enum<?>>) type;
            Enum<?>[] enumConstants = enumType.getEnumConstants();
            // 解析枚举
            List<String> enumDescList = Arrays.stream(enumConstants).map(this::obtainEnumDescription).collect(Collectors.toList());
            Object oldValue = ReflectionUtils.getField(parameterDescriptionField, parameterBuilder);
            parameterBuilder.description((oldValue == null ? "" : oldValue) + buildHtmlUnOrderList(enumDescList));
        }
        
        /**
         * 此插件是否支持处理该DocumentationType
         */
        @Override
        public boolean supports(@NonNull DocumentationType documentationType) {
            return true;
        }
        
        /**
         * 获取枚举描述
         *
         * @param enumObj 枚举对象
         *
         * @return 枚举描述
         */
        private String obtainEnumDescription(@NonNull Enum<?> enumObj) {
            String name = enumObj.name();
            /*
             * 枚举说明器示例:
             *
             * public interface EnumDescriptor {
             *     // 获取枚举项说明
             *     String obtainDescription();
             * }
             */
            if (enumObj instanceof EnumDescriptor) {
                return name + "：" + ((EnumDescriptor) enumObj).obtainDescription();
            }
            return name;
        }
        
        /**
         * 构建无序列表html
         *
         * @param itemList 列表元素
         *
         * @return 无序列表html
         */
        private String buildHtmlUnOrderList(@Nullable List<String> itemList) {
            if (CollectionUtils.isEmpty(itemList)) {
                return "";
            }
            StringBuilder sb = new StringBuilder();
            sb.append("<ul>");
            for (String item : itemList) {
                sb.append("<li>");
                sb.append(item);
                sb.append("</li>");
            }
            sb.append("</ul>");
            return sb.toString();
        }
    }
}

第三步：放行相关资源 & 保证启动了knife4j

• 放行相关资源

  对于管控了权限的应用，应放行以下资源

  /** 对于管控了权限的应用，应放行以下资源 */
  public static String[] RESOURCE_URLS = new String[]{"/webjars/**", "/swagger**", "/v3/api-docs", "/doc.html"};
  

• 保证启动了knife4j

  knife4j:
    # 启动knife4j（注：有时，如果我们不进行此配置，knife4j不会开启）
    # 其实核心是：保证com.github.xiaoymin.knife4j.spring.configuration.Knife4jAutoConfiguration生效即可。如果knife4j怎么也没启动，请debug此类，确保其被加载
    enable: true
    # 添加自定义文档
    documents:
      - group: my-group # 这里的group是处理自定义文档时用到的标识，自定义唯一即可
        # 效果等价使用 @Api(tags = "自定义文档")
        name: 自定义文档
        # 指定.md文档位置 (更多详见官网：https://doc.xiaominfo.com/docs/features/selfdocument)
        # 每个md文档的标题，则等价于 @ApiOperation(value = "md文档的标题")
        locations: classpath:api-doc/*.md
  
  # 兼容swagger3
  spring:
    mvc:
      pathmatch:
        matching-strategy: ant_path_matcher
  

第四步：测试一下

第一小步：编写controller

import com.ideaaedi.demo.controller.model.UserAddReqVO;
import com.ideaaedi.demo.controller.model.UserDetailRespVO;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import io.swagger.annotations.ApiParam;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

/**
 * 用于测试knife4j的controller
 *
 * @author <font size = "20" color = "#3CAA3C"><a href="https://gitee.com/JustryDeng">JustryDeng</a></font> <img
 * src="https://gitee.com/JustryDeng/shared-files/raw/master/JustryDeng/avatar.jpg" />
 * @since 1.0.0
 */
@RestController
@Api(tags = "我是DemoController")
public class TestController {
    
    @GetMapping("/hello")
    @ApiOperation(value = "哈喽")
    public String hello(@ApiParam(name = "name", value = "姓名", required = true) @RequestParam String name) {
        return "hello " + name;
    }
    
    @GetMapping("/hi")
    @ApiOperation(value = "嘿")
    public String hei(@ApiParam(name = "name", value = "姓名", required = true) @RequestParam String name) {
        return "hello " + name;
    }
    
    @PostMapping("/user/add")
    @ApiOperation(value = "新增用户")
    public UserDetailRespVO addUser(@RequestBody UserAddReqVO req) {
        UserDetailRespVO resp = new UserDetailRespVO();
        resp.setId(9527L);
        resp.setName(req.getName());
        resp.setAge(req.getAge());
        return resp;
    }
    
    @DeleteMapping("/user/delete/{id}")
    @ApiOperation(value = "删除用户")
    public Boolean addUser(@ApiParam(name = "id", value = "数据id", required = true) @PathVariable Long id) {
        return true;
    }
    
    /**
     * 测试 @RequestBody、@RequestParam、@PathVariable并存
     */
    @PostMapping("/multi-anno/{id}")
    @ApiOperation(value = "组合使用测试")
    public UserDetailRespVO testMultiAnno(@RequestBody UserAddReqVO req, @ApiParam(name = "name", value = "姓名",
            required = true) @RequestParam String name,
                                          @ApiParam(name = "id", value = "数据id", required = true) @PathVariable Long id) {
        UserDetailRespVO resp = new UserDetailRespVO();
        resp.setId(9527L);
        resp.setName(req.getName());
        resp.setAge(req.getAge());
        return resp;
    }
    
}

此controller中用到的相关模型

• UserAddReqVO

  import io.swagger.annotations.ApiModelProperty;
  import lombok.Data;
  
  import javax.validation.constraints.NotBlank;
  
  /**
   * 用户新增req模型
   */
  @Data
  public class UserAddReqVO {
      
      @ApiModelProperty(value = "姓名",required = true)
      @NotBlank(message = "姓名不能为空")
      private String name;
      
      @ApiModelProperty("年龄")
      private Integer age;
  }
  

• UserDetailRespVO

  import io.swagger.annotations.ApiModelProperty;
  import lombok.Data;
  
  /**
   * 用户详情resp模型
   */
  @Data
  public class UserDetailRespVO {
      
      @ApiModelProperty("id")
      private Long id;
      
      @ApiModelProperty("姓名")
      private String name;
      
      @ApiModelProperty("年龄")
      private Integer age;
  }
  

第二小步：启动项目，访问api文档

启动项目后，直接访问http://{ip}:{端口}/doc.html即可

说明：

• 文档分组（不设置则默认分组名称为default）：可切换观察其余分组下的api
• 主页：概览
• Swagger Models：可以查看所有请求模型的信息
• 文档管理：可以导出文档、进行高级设置（如设置后处理脚本等）、进行全局参数设置、查看api信息
• 自定义文档：可以添加一些自定义的md格式的文档
• 点击进入文档后，会展示api的详细信息，也可以进行调试，还可以打开api json数据等等

相关资料

• demo代码下载（knife4j-swagger3-springboot2分支）
• knife4j官网
• 本文已被收录进《程序员成长笔记》 ，笔者JustryDeng