1. Swagger依赖

<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger-ui</artifactId>
    <version>2.9.2</version>
</dependency>
<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger2</artifactId>
    <version>2.9.2</version>
</dependency>

SpringBoot 整合Swagger2 踩坑记录

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

报错的原因是由于SpringBoot的版本跟Swagger的版本有冲突。
SpringBoot用的2.6.1的版本，Swagger用的2.9.2的版本；最后降低了SpringBoot的版本为2.5.6解决了问题。

2. Swagger配置文件

package com.skyi.security.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;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

/**
 * @Classname SwaggerConfig Swagger2配置类
 * @Description TODO
 * @Version 1.0.0
 * @Date 2021/12/7 9:03
 * @Created by pts
 */
@Configuration
@EnableSwagger2
public class SwaggerConfig {
    @Bean
    public Docket createRestApi() {
        return new Docket(DocumentationType.SWAGGER_2)
                .apiInfo(apiInfo())
                //是否开启 (true 开启  false隐藏。生产环境建议隐藏)
                //.enable(false)
                .select()
                //扫描的路径包,设置basePackage会将包下的所有被@Api标记类的所有方法作为api
                .apis(RequestHandlerSelectors.basePackage("com.skyi.security.controller"))
                //指定路径处理PathSelectors.any()代表所有的路径
                .paths(PathSelectors.any())
                .build();
    }

    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                //设置文档标题(API名称)
                .title("SpringBoot中使用Swagger2接口规范")
                //文档描述
                .description("接口说明")
                //服务条款URL
                .termsOfServiceUrl("http://localhost:8086/")
                //版本号
                .version("1.0.0")
                .build();
    }
}

3. 测试控制器

package com.skyi.security.controller;


import com.skyi.security.common.Result;
import com.skyi.security.entity.User;
import com.skyi.security.service.UserService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiImplicitParam;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

/**
 * <p>
 *  前端控制器
 * </p>
 *
 * @author pts
 * @since 2021-12-06
 */
@RestController
@RequestMapping("/user/")
@CrossOrigin
@Api(value = "测试接口", tags = "用户管理相关的接口", description = "用户测试接口")
public class UserController {
    @Autowired
    private UserService userService;

    @PostMapping("register")
    //方法参数说明，name参数名；value参数说明，备注；dataType参数类型；required 是否必传；defaultValue 默认值
    @ApiImplicitParam(name = "user", value = "新增用户数据",dataType = "User",required = true)
    //说明是什么方法(可以理解为方法注释)
    @ApiOperation(value = "添加用户", notes = "添加用户")
    public Result register(@RequestBody User user){
        List<User> list = userService.lambdaQuery().eq(User::getUsername, user.getUsername()).list();
        if (list.size()>0){
            return Result.failed("用户已存在!");
        }
        boolean flag = userService.save(user);
        if (flag)
            return Result.succeed("注册成功!");
        else
            return Result.failed("注册失败!");
    }
}