SpringBoot整合Mybatis-Plus（包含逆向自动生成代码）

痛定思痛。 2022-10-09 03:25 215阅读 0赞

### 文章目录 ###

*   *  一。简介
     *  二。数据库准备
     *  三。项目搭建
     *  四。项目运行
     *  五。总结

--------------------

## 一。简介 ##

`MyBatis-Plus`(opens new window)（简称 MP）是一个 MyBatis (opens new window)的增强工具，在 MyBatis 的基础上只做增强不做改变，为简化开发、提高效率而生。

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70]  
**特性：**

*  **无侵入**：只做增强不做改变，引入它不会对现有工程产生影响，如丝般顺滑
 *  **损耗小**：启动即会自动注入基本 CURD，性能基本无损耗，直接面向对象操作
 *  **强大的 CRUD 操作**：内置通用 Mapper、通用 Service，仅仅通过少量配置即可实现单表大部分 CRUD 操作，更有强大的条件构造器，满足各类使用需求
 *  **支持 Lambda 形式调用**：通过 Lambda 表达式，方便的编写各类查询条件，无需再担心字段写错
 *  **支持主键自动生成**：支持多达 4 种主键策略（内含分布式唯一 ID 生成器 - Sequence），可自由配置，完美解决主键问题
 *  **支持 ActiveRecord 模式**：支持 ActiveRecord 形式调用，实体类只需继承 Model 类即可进行强大的 CRUD 操作
 *  **支持自定义全局通用操作**：支持全局通用方法注入（ Write once, use anywhere ）
 *  **内置代码生成器**：采用代码或者 Maven 插件可快速生成 Mapper 、 Model 、 Service 、 Controller 层代码，支持模板引擎，更有超多自定义配置等您来使用
 *  **内置分页插件**：基于 MyBatis 物理分页，开发者无需关心具体操作，配置好插件之后，写分页等同于普通 List 查询
 *  **分页插件支持多种数据库**：支持 MySQL、MariaDB、Oracle、DB2、H2、HSQL、SQLite、Postgre、SQLServer 等多种数据库
 *  **内置性能分析插件**：可输出 Sql 语句以及其执行时间，建议开发测试时启用该功能，能快速揪出慢查询
 *  **内置全局拦截插件**：提供全表 delete 、 update 操作智能分析阻断，也可自定义拦截规则，预防误操作

官方API文档地址：[https://mp.baomidou.com/guide/\#%E7%89%B9%E6%80%A7][https_mp.baomidou.com_guide_E7_89_B9_E6_80_A7]

## 二。数据库准备 ##

这里采用的是`mysql`数据库，数据库名称为`storeprocedure`，数据表名称为`student_info`：

SET NAMES utf8mb4;
    SET FOREIGN_KEY_CHECKS = 0;
    
    -- ----------------------------
    -- Table structure for student_info
    -- ----------------------------
    DROP TABLE IF EXISTS `student_info`;
    CREATE TABLE `student_info`  (
      `id` int(11) NOT NULL,
      `name` varchar(15) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL,
      `age` int(3) NULL DEFAULT NULL,
      `sex` varchar(2) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL,
      `create_time` datetime(0) NULL DEFAULT NULL,
      `create_by` varchar(15) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL,
      `update_time` datetime(0) NULL DEFAULT NULL,
      `update_by` varchar(15) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL,
      PRIMARY KEY (`id`) USING BTREE
    ) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_bin ROW_FORMAT = Dynamic;
    
    -- ----------------------------
    -- Records of student_info
    -- ----------------------------
    INSERT INTO `student_info` VALUES (1, '张三', 20, '男', '2021-06-16 16:26:12', 'administrator', NULL, NULL);
    INSERT INTO `student_info` VALUES (2, '李四', 20, '男', '2021-06-23 16:26:15', 'administrator', NULL, NULL);
    INSERT INTO `student_info` VALUES (3, '王五', 21, '男', '2021-06-22 16:26:26', 'administrator', NULL, NULL);

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70 1]

## 三。项目搭建 ##

1.首先在pom.xml文件中引入`mybatis-plus`的主要依赖：

<dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>3.4.1</version>
            </dependency>
    
            
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus</artifactId>
                <version>3.4.1</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.apache.velocity</groupId>
                <artifactId>velocity-engine-core</artifactId>
                <version>2.3</version>
            </dependency>

2.代码生成器依赖：

<dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-generator</artifactId>
                <version>3.4.1</version>
            </dependency>

3.完整pom.xml文件内容：

<?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.3.2.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.example</groupId>
        <artifactId>mybatisplus-demo</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>mybatisplus-demo</name>
        <description>Demo project for Spring Boot</description>
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            
            
            <dependency>
                <groupId>io.springfox</groupId>
                <artifactId>springfox-swagger-ui</artifactId>
                <version>2.6.1</version>
            </dependency>
            <dependency>
                <groupId>io.springfox</groupId>
                <artifactId>springfox-swagger2</artifactId>
                <version>2.6.1</version>
            </dependency>
    
            
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-generator</artifactId>
                <version>3.4.1</version>
            </dependency>
    
            
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>3.4.1</version>
            </dependency>
    
            
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus</artifactId>
                <version>3.4.1</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.apache.velocity</groupId>
                <artifactId>velocity-engine-core</artifactId>
                <version>2.3</version>
            </dependency>
    
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <scope>runtime</scope>
            </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-starter-web</artifactId>
                <version>RELEASE</version>
                <scope>compile</scope>
            </dependency>
    
            
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>RELEASE</version>
                <scope>compile</scope>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    </project>

4.代码生成器代码如下：

package com.example.mybatisplusdemo;
    
    import com.baomidou.mybatisplus.generator.AutoGenerator;
    import com.baomidou.mybatisplus.generator.config.*;
    import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
    
    public class CodeGenerator { 
    
    
        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");
            String projectPath = "D:\\mybaitsplus_generation_code";//代码生成地址
    
            gc.setOutputDir(projectPath + "/src/main/java");
            gc.setAuthor("keson");
            gc.setOpen(false);
            gc.setSwagger2(true); //实体属性 Swagger2 注解
            mpg.setGlobalConfig(gc);
    
            // 数据源配置
            DataSourceConfig dsc = new DataSourceConfig();
            dsc.setUrl("jdbc:mysql://localhost:3306/storeprocedure?useUnicode=true&useSSL=false&characterEncoding=utf8");
            // dsc.setSchemaName("public");
            dsc.setDriverName("com.mysql.cj.jdbc.Driver");
            dsc.setUsername("root");
            dsc.setPassword("root");
            mpg.setDataSource(dsc);
    
            // 包配置
            PackageConfig pc = new PackageConfig();
            pc.setModuleName("");
            pc.setParent("com.example.mybatisplusdemo");
            mpg.setPackageInfo(pc);
            
            // 策略配置
            StrategyConfig strategy = new StrategyConfig();
            strategy.setNaming(NamingStrategy.underline_to_camel);
            strategy.setColumnNaming(NamingStrategy.underline_to_camel);
    // strategy.setSuperEntityClass("你自己的父类实体,没有就不用设置!");
            strategy.setEntityLombokModel(true);
            strategy.setRestControllerStyle(true);
            // 公共父类
    // strategy.setSuperControllerClass("你自己的父类控制器,没有就不用设置!");
            // 写于父类中的公共字段
    // strategy.setSuperEntityColumns("id");
            strategy.setInclude("student_info".split(","));
            strategy.setControllerMappingHyphenStyle(true);
            strategy.setTablePrefix(pc.getModuleName() + "_");
            mpg.setStrategy(strategy);
            mpg.execute();
        }
    
    }

5.运行生成代码如下结构：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70 2]  
6.将代码移入项目中，xml一般放在resource目录下，整理后项目结构如下：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70 3]  
7.在启动类中加入`@MapperScan`注解，扫描Dao层的接口：

@SpringBootApplication
    @MapperScan("com.example.mybatisplusdemo.mapper")
    public class MybatisplusDemoApplication { 
    
        public static void main(String[] args) { 
            SpringApplication.run(MybatisplusDemoApplication.class, args);
        }
    }

8.application.yml配置文件如下：

server:
      port: 8080 #端口号
    
    spring:
      application:
        name: mybatisplus-demo #服务名称
      datasource: #数据库连接信息
        url: jdbc:mysql://localhost:3306/storeprocedure?useUnicode=true&useSSL=false&characterEncoding=utf8&serverTimezone=Asia/Shanghai
        username: root
        password: root
        driver-class-name: com.mysql.cj.jdbc.Driver
    
    #xml文件所在地址
    mybatis-plus:
      mapper-locations: classpath:xml/*.xml

9.实体类StudentInfo 代码：

@Data
    @EqualsAndHashCode(callSuper = false)
    @ApiModel(value="StudentInfo对象", description="")
    public class StudentInfo implements Serializable { 
    
        private static final long serialVersionUID = 1L;
    
        private Integer id;
    
        private String name;
    
        private Integer age;
    
        private String sex;
    
        private LocalDateTime createTime;
    
        private String createBy;
    
        private LocalDateTime updateTime;
    
        private String updateBy;
        
    }

10.在StudentInfoMapper接口加上`@Repository`注解：

@Repository
    public interface StudentInfoMapper extends BaseMapper<StudentInfo> { 
    
        List<StudentInfo> listAll();
        
    }

在StudentInfoMapper.xml文件中实现相应的方法：

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="com.example.mybatisplusdemo.mapper.StudentInfoMapper">
    
        
        <sql id="Base_Column_List">
           id,name,age,sex,create_time,create_by,update_time,update_by
        </sql>
    
        
        <resultMap id="Base_Result_Map" type="com.example.mybatisplusdemo.entity.StudentInfo">
            <result column="id" property="id"/>
            <result column="name" property="name"/>
            <result column="age" property="age"/>
            <result column="sex" property="sex"/>
            <result column="create_time" property="createTime"/>
            <result column="create_by" property="createBy"/>
            <result column="update_time" property="updateTime"/>
            <result column="update_by" property="updateBy"/>
        </resultMap>
    
        <select id="listAll" resultMap="Base_Result_Map">
            select
            <include refid="Base_Column_List"></include>
            from student_info
        </select>
    
    
    </mapper>

11.IStudentInfoService：

public interface IStudentInfoService extends IService<StudentInfo> { 
    
        List<StudentInfo> listAll();
    
    }

StudentInfoServiceImpl：

@Service
    public class StudentInfoServiceImpl extends ServiceImpl<StudentInfoMapper, StudentInfo> implements IStudentInfoService { 
    
        @Autowired
        private StudentInfoMapper studentInfoMapper;
    
        @Override
        public List<StudentInfo> listAll() { 
            return studentInfoMapper.listAll();
        }
    
    }

12.控制器层StudentInfoController：

@RestController
    @RequestMapping("/student-info")
    public class StudentInfoController { 
    
        @Autowired
        private IStudentInfoService studentInfoService;
    
        @GetMapping("listAll")
        public List<StudentInfo> listAll(){ 
            return studentInfoService.listAll();
        }
    
    }

## 四。项目运行 ##

1.启动项目：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70 4]  
2.使用postman访问，测试接口，接口返回数据成功：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70 5]

## 五。总结 ##

本篇博客只是笼统介绍一下SpringBoot如何整合Mybatis-Plus，所以只是涉及到一些教学的简单操作，之后可以根据对应的业务逻辑扩写代码。

public interface BaseMapper<T> extends Mapper<T> { 
        int insert(T entity);
    
        int deleteById(Serializable id);
    
        int deleteByMap(@Param("cm") Map<String, Object> columnMap);
    
        int delete(@Param("ew") Wrapper<T> queryWrapper);
    
        int deleteBatchIds(@Param("coll") Collection<? extends Serializable> idList);
    
        int updateById(@Param("et") T entity);
    
        int update(@Param("et") T entity, @Param("ew") Wrapper<T> updateWrapper);
    
        T selectById(Serializable id);
    
        List<T> selectBatchIds(@Param("coll") Collection<? extends Serializable> idList);
    
        List<T> selectByMap(@Param("cm") Map<String, Object> columnMap);
    
        T selectOne(@Param("ew") Wrapper<T> queryWrapper);
    
        Integer selectCount(@Param("ew") Wrapper<T> queryWrapper);
    
        List<T> selectList(@Param("ew") Wrapper<T> queryWrapper);
    
        List<Map<String, Object>> selectMaps(@Param("ew") Wrapper<T> queryWrapper);
    
        List<Object> selectObjs(@Param("ew") Wrapper<T> queryWrapper);
    
        <E extends IPage<T>> E selectPage(E page, @Param("ew") Wrapper<T> queryWrapper);
    
        <E extends IPage<Map<String, Object>>> E selectMapsPage(E page, @Param("ew") Wrapper<T> queryWrapper);
    }

该项目已经上传至Gitee，有兴趣的小伙伴可自行下载：

[https://gitee.com/hair\_gel\_king/mybatisplus-demo][https_gitee.com_hair_gel_king_mybatisplus-demo]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70]: /images/20221005/1c97ae21b6f547dca5c7cd3067ac9c07.png
[https_mp.baomidou.com_guide_E7_89_B9_E6_80_A7]: https://mp.baomidou.com/guide/#%E7%89%B9%E6%80%A7
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70 1]: /images/20221005/e15c44c99e0c47e8b3739208c4fd2f3d.png
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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70 3]: /images/20221005/a4cf0d7c513b401fa483af558dd2cd6a.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70 4]: /images/20221005/e35d782b282a47b28f118c168622ac8b.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70 5]: /images/20221005/761b772721694b989b9367c25b68df55.png
[https_gitee.com_hair_gel_king_mybatisplus-demo]: https://gitee.com/hair_gel_king/mybatisplus-demo