1 Gradle配置
在dependencies中添加以下依賴：

implementation("io.springfox:springfox-swagger2:2.7.0")
implementation("io.springfox:springfox-swagger-ui:2.7.0")

具體的版本可以在https://mvnrepository.com/artifact/io.springfox中查看到

2 添加Swagger2配置類

package com.learning.test;

import org.springframework.context.annotation.Bean;
 
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
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.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.Contact;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
 
import springfox.documentation.swagger2.annotations.EnableSwagger2;

@Configuration
@EnableWebMvc
@EnableSwagger2
public class Swagger2Configuration implements WebMvcConfigurer {
  
//swagger2的配置文件，這裏可以配置swagger2的一些基本的內容，比如掃描的包等等
  @Bean
  public Docket createRestApi() {
    return new Docket(DocumentationType.SWAGGER_2)
        .apiInfo(apiInfo())
        .select()
        .apis(RequestHandlerSelectors.basePackage("com.learning.test.controller"))
        .paths(PathSelectors.any())
        .build();
  }

  // 構建api文檔的詳細信息
  private ApiInfo apiInfo() {
    return new ApiInfoBuilder()
        // 頁面標題
        .title("API接口說明")
        // 創建人
        .contact(new Contact("lasdaybg", "", ""))
        // 版本號
        .version("")
        // 描述
        .description("")
        .build();
  }
  
  @Override
  public void addResourceHandlers(ResourceHandlerRegistry registry) {
      registry.addResourceHandler("swagger-ui.html")
              .addResourceLocations("classpath:/META-INF/resources/");

      registry.addResourceHandler("/webjars/**")
              .addResourceLocations("classpath:/META-INF/resources/webjars/");
  }
}

3 Controller示例

package com.learning.test.controller;

import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import com.learning.test.model.MyObject;

import io.swagger.annotations.Api;
import io.swagger.annotations.ApiImplicitParam;
import io.swagger.annotations.ApiImplicitParams;
import io.swagger.annotations.ApiOperation;

@RestController
@RequestMapping(value = "/test")
@Api("測試接口")
public class TestController {
  @RequestMapping(method = RequestMethod.GET)
  @ApiOperation(value = "查詢對象")
  @ApiImplicitParams({
      @ApiImplicitParam(name = "param1", value = "入參1"),
      @ApiImplicitParam(name = "param2", value = "入參2")})
  public MyObject get(@RequestParam(required = false) String param1,
                      @RequestParam(required = false) String param2) {
    return new MyObject();
  }

  @RequestMapping(method = RequestMethod.POST, consumes = MediaType.APPLICATION_JSON_UTF8_VALUE)
  @ApiOperation(value = "創建對象")
  public void create(@RequestBody(required = false) MyObject myObject) {}
}

MyObject的類聲明如下：
package com.learning.test.model;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

@Data
@ApiModel(value = "MyObject", description = "數據模型")
public class MyObject {

  @ApiModelProperty(value = "名稱")
  private String name;

  @ApiModelProperty(value = "參數1")
  private Integer param1;

  @ApiModelProperty(value = "參數2")
  private Boolean param2;
}

這裏用到了幾類註解：
@Api
用在類上，說明這個是Swagger的資源

@ApiOperation
用在方法上，對方法功能做一個說明

@ApiImplicitParams，ApiImplicitParam
用在方法上，對方法的入參進行說明

@ApiModel
用在模型對象上，對對象的屬性等進行說明

另外，這裏用到了lombok，具體用法請自行百度。

4 查看swagger文檔

啟動程序，在瀏覽器中輸入http://localhost:8080/swagger-ui.html，即可看到swagger的文檔說明

SpringBoot中部署Swagger2和Swagger-UI