1、创建项目

打开Ider，创建springboot项目。创建页面勾选需要的依赖，自定义包名、存储位置等，然后创建项目
pom依赖如下

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.2</version>
        </dependency>

        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
    </dependencies>

编写配置文件

application.yml

server:
  port: 8081
spring:
  mvc:
    path match:
      matching-strategy: ant_path_matcher
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: 123456
    url: jdbc:mysql://localhost:3306/demo01?useUnicode=true&useSSL=false&characterEncoding=utf8&serverTimezone=GMT%2b8

启动SpringBootApplication ，看是否能够成功跑起来

2、创建数据库

创建数据库demo01，创建user表，建表语言如下

CREATE DATABASE /*!32312 IF NOT EXISTS*/`demo01` /*!40100 DEFAULT CHARACTER SET utf8 */;

USE `demo01`;

/*Table structure for table `user` */

DROP TABLE IF EXISTS `user`;

CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT 'id',
  `name` varchar(50) DEFAULT NULL COMMENT '用户名',
  `password` varchar(50) DEFAULT NULL COMMENT '密码',
  `address` varchar(255) DEFAULT NULL COMMENT '地址',
  `creat_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '创建时间',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

/*Data for the table `user` */

insert  into `user`(`id`,`name`,`password`,`address`,`creat_time`) values 

(1,'张三','123456','江西省南昌市','2022-11-16 18:04:48'),

(2,'李四','123456','江西省南昌市','2022-11-16 19:49:31');

3、整合mybatis-plus

导入依赖

<!--整合mybatis-plus-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.2.0</version>
        </dependency>
        <!--页面模板引擎-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-freemarker</artifactId>
        </dependency>

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>3.2.0</version>
        </dependency>

添加配置文件

server:
  port: 8081
spring:
  mvc:
    path match:
      matching-strategy: ant_path_matcher
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: 123456
    url: jdbc:mysql://localhost:3306/demo01?useUnicode=true&useSSL=false&characterEncoding=utf8&serverTimezone=GMT%2b8

mybatis-plus:
  mapper-locations:classpath*:/mapper/**Mapper.xml

写mybatis-plus配置 (直接cv就好，都是不变的，除了包名等)

MyBatisPlusConfig.java

package com.xqh.demo.config;

import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration   //组件，添加到容器
@EnableTransactionManagement  //开启事务管理
@MapperScan("com.xqh.demo.mapper")  //开启mapper接口扫描
public class MybatisPlusConfig {
    //添加分页插件
    @Bean
    public PaginationInterceptor paginationInterceptor(){
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        return paginationInterceptor;
    }

}

代码自动生成器

CodeGenerator.java

package com.xqh.demo;

import com.baomidou.mybatisplus.core.exceptions.MybatisPlusException;
import com.baomidou.mybatisplus.core.toolkit.StringPool;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.InjectionConfig;
import com.baomidou.mybatisplus.generator.config.*;
import com.baomidou.mybatisplus.generator.config.po.TableInfo;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class CodeGenerator {
    public static String scanner(String tip) {
        Scanner scanner = new Scanner(System.in);
        StringBuilder help = new StringBuilder();
        help.append("请输入" + tip + "：");
        System.out.println(help.toString());
        if (scanner.hasNext()) {
            String ipt = scanner.next();
            if (StringUtils.isNotEmpty(ipt)) {
                return ipt;
            }
        }
        throw new MybatisPlusException("请输入正确的" + tip + "！");
    }

    public static void main(String[] args) {
        // 代码生成器
        AutoGenerator mpg = new AutoGenerator();

        // 全局配置
        GlobalConfig gc = new GlobalConfig();
        String projectPath = System.getProperty("user.dir");
        gc.setOutputDir(projectPath + "/src/main/java");
        gc.setAuthor("xqh");
        gc.setOpen(false);
        // gc.setSwagger2(true); 实体属性 Swagger2 注解
        gc.setServiceName("%sService");
        mpg.setGlobalConfig(gc);

        // 数据源配置
        DataSourceConfig dsc = new DataSourceConfig();
        dsc.setUrl("jdbc:mysql://localhost:3306/demo01?useUnicode=true&useSSL=false&characterEncoding=utf8&serverTimezone=Asia/Shanghai");
        // dsc.setSchemaName("public");
        dsc.setDriverName("com.mysql.cj.jdbc.Driver");
        dsc.setUsername("root");
        dsc.setPassword("123456");
        mpg.setDataSource(dsc);

        // 包配置
        PackageConfig pc = new PackageConfig();
        pc.setModuleName(null);
        pc.setParent("com.xqh.demo");
        mpg.setPackageInfo(pc);

        // 自定义配置
        InjectionConfig cfg = new InjectionConfig() {
            @Override
            public void initMap() {
                // to do nothing
            }
        };

        // 如果模板引擎是 freemarker
        String templatePath = "/templates/mapper.xml.ftl";
        // 如果模板引擎是 velocity
        // String templatePath = "/templates/mapper.xml.vm";

        // 自定义输出配置
        List<FileOutConfig> focList = new ArrayList<>();
        // 自定义配置会被优先输出
        focList.add(new FileOutConfig(templatePath) {
            @Override
            public String outputFile(TableInfo tableInfo) {
                // 自定义输出文件名 ， 如果你 Entity 设置了前后缀、此处注意 xml 的名称会跟着发生变化！！
                return projectPath + "/src/main/resources/mapper/"
                        + "/" + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;
            }
        });

        cfg.setFileOutConfigList(focList);
        mpg.setCfg(cfg);

        // 配置模板
        TemplateConfig templateConfig = new TemplateConfig();

        templateConfig.setXml(null);
        mpg.setTemplate(templateConfig);

        // 策略配置
        StrategyConfig strategy = new StrategyConfig();
        strategy.setNaming(NamingStrategy.underline_to_camel);
        strategy.setColumnNaming(NamingStrategy.underline_to_camel);
        strategy.setEntityLombokModel(true);
        strategy.setRestControllerStyle(true);
        strategy.setInclude(scanner("表名，多个英文逗号分割").split(","));
        strategy.setControllerMappingHyphenStyle(true);
        strategy.setTablePrefix("m_");
        mpg.setStrategy(strategy);
        mpg.setTemplateEngine(new FreemarkerTemplateEngine());
        mpg.execute();
    }
}

ps:记得修改包名和文件名，和自己项目所匹配

运行CodeGenerator.java

输入表名，一键生成代码

写一个测试接口，来看能不能从数据库中读取数据

UserController.java

@RestController
@RequestMapping("/user")  //给接口加前缀
public class UserController {
    @Autowired
    UserService userService;

    @GetMapping("/{id}")
    public Object test1(@PathVariable("id")Long id){
        return userService.getById(id);
    }
}

运行程序，输入id，看能不能拿到数据库中的数据

4、整合swagger

为了方便测试接口，可以整合swagger，可视化界面里调试和测试接口（也可以用外置软件Postman）。但是我感觉用swagger更方便，添加好依赖就行
导入依赖

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

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

用的2.9.2的版本，亲测用3.0.0会进不去swagegr-ui.html的页面，可能是因为springboot和swagger版本不兼容的原因
有启动器的那个整合依赖，但是有时候会出现版本不兼容的问题导致进不去swagger页面，这里用的是两个依赖，测试后可以成功进入swagger页面
如果springboot启动报错，在application.yml中加上这一串配置

spring:
  mvc:
    path match:
      matching-strategy: ant_path_matcher

写swagegr配置

SwaggerConfig.java

package com.xqh.demo.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.service.Contact;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;
@Configuration
@EnableSwagger2
public class SwaggerConfig {
    @Bean
    public Docket restApi() {
        return new Docket(DocumentationType.SWAGGER_2)
                .groupName("标准接口")
                .apiInfo(apiInfo("Spring Boot中使用Swagger2构建RESTFUL APIs", "1.0"))
                .useDefaultResponseMessages(true)
                .forCodeGeneration(false)
                .select()
                .apis(RequestHandlerSelectors.basePackage("com.xqh.demo.controller"))
                .paths(PathSelectors.any())
                .build();
    }

    private ApiInfo apiInfo(String title, String version) {
        return new ApiInfoBuilder()
                .title(title)
                .description("更多请关注: https://blog.csdn.net/m0_56116754?spm=1000.2115.3001.5343")
                .termsOfServiceUrl("https://blog.csdn.net/m0_56116754?spm=1000.2115.3001.5343")
                .contact(new Contact("xqh", "https://blog.csdn.net/m0_56116754?spm=1000.2115.3001.5343", "791172229@qq.com"))
                .version(version)
                .build();
    }
}