【Spring Boot】2. 整合Mybaits & Mybatis的逆向工程Demo

以你之姓@ 2021-09-30 14:46 253阅读 0赞

Spring Boot操作数据库有jpa，但我们也可以引入Mybatis框架进行对数据库的操作，而Mybatis的逆向工程可以方便我们进行开发。

# 1. 是什么 #

Mybatis逆向工程，可以通过配置数据库信息，配置对应参数，由数据库表生成对应的Mapper接口跟mapper.xml文件，以及实体类Bean，方便我们进行开发，让我们不用再去写mapper.xml配置文件。

# 2. 使用过程 #

## 2.1 创建一个Spring Boot简单Web工程 ##

这里引用另外一篇博客：[简单Spring Boot应用启动Demo & 启动类扫描范围][Spring Boot_Demo _]  
按照博客先创建一个Spring Boot Demo

## 2.2 配置pom.xml ##

引入跟Mybatis逆向工程相关的包，以及Mysql相关的包：

<dependencies>
            
            
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis</artifactId>
                <version>3.4.2</version>
            </dependency>
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.41</version>
            </dependency>
    
    		
            
            <dependency>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-core</artifactId>
                <version>1.3.5</version>
            </dependency>
        </dependencies>

## 2.3 创建数据库表 ##

use mbg;
    CREATE TABLE `people` (
      `id` int auto_increment,
      `age` int NOT NULL,
      `weight` double NOT NULL,
      `height` double NOT NULL,
      `name` varchar(50) NOT NULL,
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8;

创建结果：  
![在这里插入图片描述][20191125233518485.png]

## 2.4 IDEA编写配置文件 ##

编写mbg.xml与pom.xml放在同一目录

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN" "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
    <generatorConfiguration>
    
        <context id="DB2Tables" targetRuntime="MyBatis3">
            <commentGenerator>
                <property name="suppressAllComments" value="true" />
            </commentGenerator>
            
            <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/mbg" userId="root" password="88888">
            </jdbcConnection>
    
            <javaTypeResolver>
                <property name="forceBigDecimals" value="false" />
            </javaTypeResolver>
    
            
            <javaModelGenerator targetPackage="com.server.bean" targetProject=".\src\main\java">
                <property name="enableSubPackages" value="true" />
                <property name="trimStrings" value="true" />
            </javaModelGenerator>
    
            
            <sqlMapGenerator targetPackage="mapper" targetProject=".\src\main\resources">
                <property name="enableSubPackages" value="true" />
            </sqlMapGenerator>
    
            
            <javaClientGenerator type="XMLMAPPER" targetPackage="com.server.dao" targetProject=".\src\main\java">
                <property name="enableSubPackages" value="true" />
            </javaClientGenerator>
    
            
            <table tableName="people" domainObjectName="People"/>
        </context>
    </generatorConfiguration>

## 2.5 编写生成代码 ##

import java.io.File;
    import java.util.ArrayList;
    import java.util.List;
    
    import org.mybatis.generator.api.MyBatisGenerator;
    import org.mybatis.generator.config.Configuration;
    import org.mybatis.generator.config.xml.ConfigurationParser;
    import org.mybatis.generator.internal.DefaultShellCallback;
    
    public class Main { 
    
        public static void main(String[] args) throws Exception { 
            List<String> warnings = new ArrayList<String>();
            boolean overwrite = true;
            File configFile = new File("mbg.xml");
            ConfigurationParser cp = new ConfigurationParser(warnings);
            Configuration config = cp.parseConfiguration(configFile);
            DefaultShellCallback callback = new DefaultShellCallback(overwrite);
            MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config,
                    callback, warnings);
            myBatisGenerator.generate(null);
        }
    }

1.  执行

执行前：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FwcGx5aW5n_size_16_color_FFFFFF_t_70]  
执行后：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FwcGx5aW5n_size_16_color_FFFFFF_t_70 1]

生成对应的mapper文件：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FwcGx5aW5n_size_16_color_FFFFFF_t_70 2]  
Mapper接口：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FwcGx5aW5n_size_16_color_FFFFFF_t_70 3]  
bean类：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FwcGx5aW5n_size_16_color_FFFFFF_t_70 4]

# 3. 整合Mybatis： #

## 3.1 配置数据源 ##

注意需要配置数据源，以及mapper.xml文件的位置，application.yml文件：

spring:
      datasource:
        url: jdbc:mysql://127.0.0.1:3306/mbg?useUnicode=true&characterEncoding=UTF-8&useSSL=false
        driverClassName: com.mysql.jdbc.Driver
        username: root
        password: 12345678
    
    mybatis:
      mapper-locations: classpath:mapper/*.xml

## 3.2 更新pom.xml ##

当前的pom.xml：

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>com.parallelline1996</groupId>
        <artifactId>springboot-mbg-demo</artifactId>
        <version>1.0-SNAPSHOT</version>
    
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.22.RELEASE</version>
            <relativePath/>
        </parent>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis</artifactId>
                <version>3.4.2</version>
            </dependency>
    
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.41</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-core</artifactId>
                <version>1.3.5</version>
            </dependency>
    
            <dependency>
                <groupId>tk.mybatis</groupId>
                <artifactId>mapper-spring-boot-starter</artifactId>
                <version>2.0.2</version>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    </project>

## 3.3 对Mapper接口进行扫描 ##

需要新增对Mapper接口进行扫描  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FwcGx5aW5n_size_16_color_FFFFFF_t_70 5]  
同时，接口类上面也需要加入@Mapper的注解  
![在这里插入图片描述][20191126002355129.png]

# 4. 进行测试 #

编写一个简单的插入方法进行测试：

@RestController
    public class MainController { 
    
        private PeopleMapper peopleMapper;
    
        @Autowired
        MainController(PeopleMapper peopleMapper) { 
            this.peopleMapper = peopleMapper;
        }
    
        @GetMapping("/addNewUser")
        public void addNewUser() { 
            People people = new People(null, 12, 40.5, 153.4, "Tim");
            peopleMapper.insert(people);
        }
    }

发送请求到 /addNewUser接口，执行后查看数据库，发现插入成功：  
![在这里插入图片描述][20191126002150116.png]

Demo代码的github链接：  
https://github.com/Parallelline1996/Daily-Learning/tree/master/SpringBoot/code-repository/SpringBoot-Mybatis-MBG

[Spring Boot_Demo _]: https://blog.csdn.net/Applying/article/details/103247024
[20191125233518485.png]: /images/20210920/79913921a8304aa38876e7652af5c614.png
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[20191126002355129.png]: /images/20210920/c055e32a0ff94d83b664a03b23a50ad3.png
[20191126002150116.png]: /images/20210920/19a5ba71e2904bb48272a636cbc7b195.png