首先，在pom.xml中添加依赖：

<dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>io.springfox</groupId><artifactId>springfox-boot-starter</artifactId><version>3.0.0</version></dependency>
</dependencies>

创建一个配置类SwaggerConfig.java：

package org.example.testdoc.config;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;@Configuration
public class SwaggerConfig {@Beanpublic Docket api() {return new Docket(DocumentationType.SWAGGER_2).apiInfo(apiInfo()).select().apis(RequestHandlerSelectors.basePackage("org.example.testdoc.controller")).paths(PathSelectors.any()).build();}private ApiInfo apiInfo() {return new ApiInfoBuilder().title("Springfox Swagger3 Example").description("This is an example of using Springfox Swagger3 to generate API documentation.").version("1.0").build();}
}

创建一个控制器类HelloController.java：

package com.example.demo.controller;import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;@RestController
public class HelloController {@GetMapping("/hello")public String hello() {return "Hello, Spring Boot!";}
}

ExampleController类

package org.example.testdoc.controller;import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;@Api(value = "Example Controller", tags = "example")
@RestController
public class ExampleController {@ApiOperation(value = "Get example data", notes = "This API returns example data.")@GetMapping("/example")public String getExampleData() {return "Hello, World!";}
}

主类：

package org.example.testdoc;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import springfox.documentation.oas.annotations.EnableOpenApi;@SpringBootApplication
@EnableOpenApi
public class TestdocApplication {public static void main(String[] args) {SpringApplication.run(TestdocApplication.class, args);}}

查看结果：访问Swagger UI

http://localhost:8080/swagger-ui/index.html