前言
Swagger2（基于openApi3）已经在17年停止维护了，取而代之的是 sagger3（基于openApi3），而国内几乎没有 sagger3使用的文档，百度搜出来的大部分都是swagger2的使用，这篇文章将介绍如何在 java 中使用 openApi3（swagger3）。
一、swagger 3 的使用
Open API
OpenApi是业界真正的 api 文档标准，其是由 Swagger 来维护的，并被linux列为api标准，从而成为行业标准。
Swagger
swagger 是一个 api 文档维护组织，后来成为了 Open API 标准的主要定义者，现在最新的版本为17年发布的 Swagger3（Open Api3）。国内绝大部分人还在用过时的swagger2（17年停止维护并更名为swagger3）swagger2的包名为 io.swagger，而swagger3的包名为 io.swagger.core.v3。
SpringFox
SpringFox是 spring 社区维护的一个项目（非官方），帮助使用者将 swagger2 集成到 Spring 中。常常用于 Spring 中帮助开发者生成文档，并可以轻松的在spring boot中使用。目前已经支持 OpenAPI3 标准。
升级到 OpenAPI3（java 中 swagger1.x 对应 OpenAPI2、swagger 2.x对应OpenAPI3）官方文档
3.0 相关特性
- 支持 Spring 5，Webflux（仅请求映射支持，尚不支持功能端点）、Spring Integration
- 补充官方在 spring boot 的自动装配 pringfox-boot-starter 以后可以直接依赖一个 dependency
- 与2.0更好的规范兼容性
- 支持OpenApi 3.0.3
- 轻依赖 spring-plugin，swagger-core
- 现有的swagger2批注将继续有效并丰富开放式API 3.0规范
常用注解说明
@Api：用在请求的类上，表示对类的说明
tags: 说明该类的作用，可以在UI界面上看到的注解
value: 该参数没什么意义，在UI界面上也看到，所以不需要配置
@ApiOperation：用在请求的方法上，说明方法的用途、作用
value: 说明方法的用途、作用
notes: 方法的备注说明
@ApiImplicitParams：用在请求的方法上，表示一组参数说明
@ApiImplicitParam：用在@ApiImplicitParams注解中，指定一个请求参数的各个方面
name：参数名
value：参数的汉字说明、解释
required：参数是否必须传
paramType：参数放在哪个地方
· header --> 请求参数的获取：@RequestHeader
· query --> 请求参数的获取：@RequestParam
· path（用于restful接口）--> 请求参数的获取：@PathVariable
· body（不常用）
· form（不常用）
dataType：参数类型，默认String，其它值dataType="Integer"
defaultValue：参数的默认值
@ApiResponses：用在请求的方法上，表示一组响应
@ApiResponse：用在@ApiResponses中，一般用于表达一个错误的响应信息
code：数字，例如400
message：信息，例如"请求参数没填好"
response：抛出异常的类
@ApiModel：用于响应类上，表示一个返回响应数据的信息，一般用在post创建的时候，使用@RequestBody这样的场景，请求参数无法使用@ApiImplicitParam注解进行描述的时候）
@ApiModelProperty：用在属性上，描述响应类的属性
name：属性名
value：属性的汉字说明、解释
@ApiParam 用于 Controller 中方法的参数说明，放在方法签名当中
value：参数说明
required：是否必填
@ApiIgnore：使用该注解忽略这个API
二、在项目中的使用
- 1、引入pom包，这里同时引入增强包knife4j
<!-- Swagger3 -->
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-boot-starter</artifactId>
<version>3.0.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/io.springfox/springfox-swagger-ui -->
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger-ui</artifactId>
<version>3.0.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.github.xiaoymin/knife4j-spring-boot-starter -->
<dependency>
<groupId>com.github.xiaoymin</groupId>
<artifactId>knife4j-spring-boot-starter</artifactId>
<version>3.0.3</version>
</dependency>
- 2、application.yml 添加配置，放在spring目录下面：
Springfox使用的路径匹配是基于AntPathMatcher的，而Spring Boot 2.6.X使用的是PathPatternMatcher。
# ========================================================================
# 启动报错需要修改以下mvc配置 Failed to start bean 'documentationPluginsBootstrapper'
spring:
mvc:
pathmatch:
matching-strategy: ant_path_matcher
# ========================================================================
- 3、升级spring boot到2.7.0，使用swagger 3.0报错
升级spring boot到2.7.0，项目启动报错，项目使用swagger 3.0 ,具体版本是knife4j-spring-boot-starter的3.0.3，查找解决方案，都说修改配置文件（但是修改配置后仍然无效）或者新增配置类，过滤空情况，但是仍然还是解决了很长时间。报错信息：Caused by: java.lang.NullPointerException: Cannot invoke “org.springframework.web.servlet.mvc.condition.PatternsRequestCondition.getPatterns()” because “this.condition” is null
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-06-04 12:30:54.079 [main] ERROR org.springframework.boot.SpringApplication - Application run failed
org.springframework.context.ApplicationContextException: Failed to start bean 'documentationPluginsBootstrapper'; nested exception is java.lang.NullPointerException: Cannot invoke "org.springframework.web.servlet.mvc.condition.PatternsRequestCondition.getPatterns()" because "this.condition" is null
at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:181)
at org.springframework.context.support.DefaultLifecycleProcessor.access$200(DefaultLifecycleProcessor.java:54)
at org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup.start(DefaultLifecycleProcessor.java:356)
at java.base/java.lang.Iterable.forEach(Iterable.java:75)
at org.springframework.context.support.DefaultLifecycleProcessor.startBeans(DefaultLifecycleProcessor.java:155)
at org.springframework.context.support.DefaultLifecycleProcessor.onRefresh(DefaultLifecycleProcessor.java:123)
at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:935)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:586)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:147)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:734)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:408)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:308)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295)
at com.cloud.user.UserApplication.main(UserApplication.java:41)
Caused by: java.lang.NullPointerException: Cannot invoke "org.springframework.web.servlet.mvc.condition.PatternsRequestCondition.getPatterns()" because "this.condition" is null
at springfox.documentation.spring.web.WebMvcPatternsRequestConditionWrapper.getPatterns(WebMvcPatternsRequestConditionWrapper.java:56)
at springfox.documentation.RequestHandler.sortedPaths(RequestHandler.java:113)
at springfox.documentation.spi.service.contexts.Orderings.lambda$byPatternsCondition$3(Orderings.java:89)
at java.base/java.util.Comparator.lambda$comparing$77a9974f$1(Comparator.java:473)
at java.base/java.util.TimSort.countRunAndMakeAscending(TimSort.java:355)
at java.base/java.util.TimSort.sort(TimSort.java:234)
at java.base/java.util.Arrays.sort(Arrays.java:1307)
at java.base/java.util.ArrayList.sort(ArrayList.java:1721)
at java.base/java.util.stream.SortedOps$RefSortingSink.end(SortedOps.java:392)
at java.base/java.util.stream.Sink$ChainedReference.end(Sink.java:258)
at java.base/java.util.stream.Sink$ChainedReference.end(Sink.java:258)
at java.base/java.util.stream.Sink$ChainedReference.end(Sink.java:258)
at java.base/java.util.stream.Sink$ChainedReference.end(Sink.java:258)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:510)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
at springfox.documentation.spring.web.plugins.WebMvcRequestHandlerProvider.requestHandlers(WebMvcRequestHandlerProvider.java:81)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
at springfox.documentation.spring.web.plugins.AbstractDocumentationPluginsBootstrapper.withDefaults(AbstractDocumentationPluginsBootstrapper.java:107)
at springfox.documentation.spring.web.plugins.AbstractDocumentationPluginsBootstrapper.buildContext(AbstractDocumentationPluginsBootstrapper.java:91)
at springfox.documentation.spring.web.plugins.AbstractDocumentationPluginsBootstrapper.bootstrapDocumentationPlugins(AbstractDocumentationPluginsBootstrapper.java:82)
at springfox.documentation.spring.web.plugins.DocumentationPluginsBootstrapper.start(DocumentationPluginsBootstrapper.java:100)
at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:178)
... 14 common frames omitted
解决方案
- 新增一个配置类，注意配置类不能放到swagger的配置类下，测试无效。配置Bean可以放在启动类下或者重新新增一个配置Bean，代码如下:
import lombok.extern.slf4j.Slf4j;
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.spring.web.plugins.WebFluxRequestHandlerProvider;
import springfox.documentation.spring.web.plugins.WebMvcRequestHandlerProvider;
import java.lang.reflect.Field;
import java.util.List;
import java.util.stream.Collectors;
@Slf4j
@Configuration
public class BeanPostProcessorConfig {
@Bean
public 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);
}
}
};
}
}
- 4、添加自定义配置类：
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.bind.annotation.CookieValue;
import org.springframework.web.context.request.async.DeferredResult;
import com.github.xiaoymin.knife4j.spring.annotations.EnableKnife4j;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.oas.annotations.EnableOpenApi;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.Contact;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
/**
* 文档访问地址：http://ip:port/swagger-ui/index.html
* 添加Knife4j可以导出导出离线文档，访问地址：http://ip:port/doc.html
*
*/
@Configuration
@EnableKnife4j
@EnableOpenApi
@ConditionalOnProperty(value = "spring.profiles.active", havingValue = "dev")
//@Profile({"dev","test"})
public class SwaggerConfiguration {
@Bean
public Docket createRestApis() {
return new Docket(DocumentationType.OAS_30)
.enable(true)//是否启用：注意生产环境需要关闭
.groupName("spring-boot-2.7.3")
.genericModelSubstitutes(DeferredResult.class)
.useDefaultResponseMessages(false)
.forCodeGeneration(true)
.ignoredParameterTypes(CookieValue.class)
.apiInfo(apiInfo())
.select()
//以下拦截配置可以三选一，根据需要进行添加
.apis(RequestHandlerSelectors.basePackage("com.qi.study.springboot.controller"))
.apis(RequestHandlerSelectors.withClassAnnotation(Api.class))
.apis(RequestHandlerSelectors.withMethodAnnotation(ApiOperation.class))
.paths(PathSelectors.any())
.build();
}
private ApiInfo apiInfo() {
return new ApiInfoBuilder()
.title("使用swagger生成的接口文档")
.description("开发测试")
// 服务条款URL
.termsOfServiceUrl("https://www.baidu.com/")
// 作者信息
.contact(new Contact("qihh", "https://www.baidu.com/", "qihh@136.com"))
.version("0.0.1")
.build();
}
}
- 5、添加拦截器配置，放行相关目录
import com.kfang.web.price.manager.interceptor.AuthorizationInterceptor;
import com.kfang.web.price.manager.interceptor.ContextInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import javax.annotation.Resource;
@Configuration
public class InterceptorConfiguration implements WebMvcConfigurer {
@Resource
private Environment env;
@Resource
private AuthorizationInterceptor authorizationInterceptor;
@Override
public void addInterceptors(InterceptorRegistry registry) {
String[] swaggerExcludePathPatterns = {"/doc.html","/swagger**/**","/swagger-resources/**","/webjars/**","/v3/**"};
registry.addInterceptor(new ContextInterceptor()).addPathPatterns("/**");
if("dev".equals(env.getProperty("spring.profiles.active"))){
}else{
swaggerExcludePathPatterns = new String[0];
}
registry.addInterceptor(authorizationInterceptor)
.excludePathPatterns("/user/logout")
.excludePathPatterns("/user/login")
.excludePathPatterns(swaggerExcludePathPatterns)
.addPathPatterns("/**").order(-1);
}
}
- 6、测试demo
@Api(tags = "用户",value = "用户")
@RestController
@RequestMapping(value = "/user", produces = {"application/json;charset=UTF-8"})
public class UserController {
@ApiOperation("添加")
@PostMapping("/add")
@ApiResponses({
@ApiResponse(message = "添加", code = 200, response = UserVO.class)
})
public UserVO add(@RequestBody @Valid UserAddRequest userAddRequest) {
// 将数据写到数据库
UserVO userVO = new UserVO();
BeanUtils.copyProperties(userAddRequest, userVO);
userVO.setId(1L);
userVO.setCreateTime(LocalDateTime.now());
userVO.setUpdateTime(LocalDateTime.now());
return userVO;
}
@ApiOperation("修改")
@PostMapping("/edit")
@ApiResponses({
@ApiResponse(message = "修改", code = 200, response = UserVO.class)
})
public UserVO edit(@RequestBody @Valid UserEditRequest userEditRequest) {
// 修改数据库的数据
UserVO userVO = new UserVO();
BeanUtils.copyProperties(userEditRequest, userVO);
userVO.setUpdateTime(LocalDateTime.now());
return userVO;
}
@ApiOperation("查找")
@GetMapping("/find")
@ApiResponses({
@ApiResponse(message = "查找", code = 200, response = UserQueryRequest.class)
})
public List<UserVO> find(UserQueryRequest userQueryRequest) {
return new ArrayList<>();
}
@ApiOperation("删除")
@PostMapping("/delete")
public void delete(Long id) {
// 将数据库数据删除
}
@PostMapping(value = "/fileUpload")
@ApiOperation(value = "文件上传")
@ApiResponses({
@ApiResponse(message = "文件上传", code = 200, response = AliyunUploadResult.class)
})
public String uploadFile(@RequestPart("file") MultipartFile file) {
AliyunUploadRequest uploadRequest = new AliyunUploadRequest(file);
AliyunUploadResult result = aliyunOss.fileUpload(uploadRequest);
return successInfo(result);
}
@PostMapping(value = "/importDataDetail")
@ApiOperation(value = "导入Excel源数据明细")
@ApiResponses({
@ApiResponse(message = "导入Excel源数据明细出参成功", code = 200, response = Boolean.class)
})
public String importDataDetail(@RequestPart("file") MultipartFile file,
@RequestParam("cityId") String cityId) {
}
}
三，启动测试
-
1、访问swagger-ui页面：http://localhost:8080/swagger-ui/index.html
-
2、访问knife4j-ui页面：http://localhost:8080/doc.html
knife4j是springfox-swagger的增强UI实现，为Java开发者在使用Swagger的时候，提供了简洁、强大的接口文档体验。引入pom包，并开启@EnableKnife4j注解就可以使用。
- 3、设置安全密码登录配置：
server.port=8081
knife4j.enable=true
knife4j.basic.enable=true
knife4j.basic.username=admin
knife4j.basic.password=admin
knife4j.setting.language=zh-CN
登录界面：
四、@RequestParam和@RequestPart的区别
@RequestPart
- @RequestPart这个注解用在multipart/form-data表单提交请求的方法上。
- 支持的请求方法的方式MultipartFile，属于Spring的MultipartResolver类。这个请求是通过http协议传输的
@RequestParam
- @RequestParam支持’application/json’，也同样支持multipart/form-data请求
区别
当请求方法的请求参数类型不是String 或 MultipartFile / Part时，而是复杂的请求域时，@RequestParam 依赖Converter or PropertyEditor进行数据解析， RequestPart参考 ‘Content-Type’ header，依赖HttpMessageConverters 进行数据解析
当请求为multipart/form-data时，@RequestParam只能接收String类型的name-value值，@RequestPart可以接收复杂的请求域（像json、xml）；@RequestParam 依赖Converter or PropertyEditor进行数据解析， @RequestPart参考'Content-Type' header，依赖HttpMessageConverters进行数据解析
前台请求：
jsonData为Person对象的json字符串
uploadFile为上传的图片
后台接收：
- 1、@RequestPart可以将jsonData的json数据转换为Person对象
@RequestMapping("jsonDataAndUploadFile")
@ResponseBody
public String jsonDataAndUploadFile(@RequestPart("uploadFile") MultiPartFile uploadFile,
@RequestPart("jsonData") Person person) {
StringBuilder sb = new StringBuilder();
sb.append(uploadFile.getOriginalFilename()).append(";;;"));
return person.toString() + ":::" + sb.toString();
}
- 2、@RequestParam对于jsonData的json数据只能用String字符串来接收
@RequestMapping("jsonDataAndUploadFile")
@ResponseBody
public String jsonDataAndUploadFile(@RequestPart("uploadFile") MultiPartFile uploadFile,
@RequestParam("josnData") String jsonData) {
StringBuilder sb = new StringBuilder();
sb.append(uploadFile.getOriginalFilename()).append(";;;"));
return person.toString() + ":::" + sb.toString();
}
