SpringBoot使用Mybatis-Generator

深藏阁楼爱情的钟 2022-05-14 13:12 237阅读 0赞

> 本文介绍如何将Maven和Mybatis-Generator配合使用。

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# 简介 #

Mybatis-Generator是Mybatis提供的一个便捷型插件，自动可以为项目生产对应的实体类，Mapper，dao层。

官网文档：[http://www.mybatis.org/generator/index.html][http_www.mybatis.org_generator_index.html]

# 入门案例 #

本文使用SpringBoot结合Mybatis-Generator插件使用，数据库Mysql。

## 新建项目 ##

新建一个SpringBoot项目。

### 依赖文件 ###

在项目pom文件中，引入Mybatis-Generator插件，并且引入Mybatis和Mysql依赖。完整pom代码如下：

<?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.dalaoyang</groupId>
        <artifactId>springboot_generator</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <packaging>jar</packaging>
    
        <name>springboot_generator</name>
        <description>springboot_generator</description>
    
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.15.RELEASE</version>
            <relativePath/> 
        </parent>
    
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <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>
            </dependency>
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>1.3.1</version>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-devtools</artifactId>
                <scope>runtime</scope>
            </dependency>
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <scope>runtime</scope>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.mybatis.generator</groupId>
                    <artifactId>mybatis-generator-maven-plugin</artifactId>
                    <version>1.3.2</version>
                    <executions>
                        <execution>
                            <id>mybatis-generator</id>
                            <phase>deploy</phase>
                            <goals>
                                <goal>generate</goal>
                            </goals>
                        </execution>
                    </executions>
                    <configuration>
                        
                        <configurationFile>src/main/resources/mybatis-generator/generatorConfig.xml</configurationFile>
                        <verbose>true</verbose>
                        <overwrite>true</overwrite>
                    </configuration>
                    <dependencies>
                        <dependency>
                            <groupId>mysql</groupId>
                            <artifactId>mysql-connector-java</artifactId>
                            <version>5.1.46</version>
                        </dependency>
                        <dependency>
                            <groupId>org.mybatis.generator</groupId>
                            <artifactId>mybatis-generator-core</artifactId>
                            <version>1.3.2</version>
                        </dependency>
                    </dependencies>
                </plugin>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                    <configuration>
                        <classifier>exec</classifier>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    
    
    </project>

### 配置Mybatis-Generator配置 ###

在pom文件中配置的Mybatis-Generator 工具配置文件的位置新建一个generatorConfig.xml，（本文案例配置的位置是src/main/resources/mybatis-generator/generatorConfig.xml），配置文件代码如下，具体配置需要自行修改至自己的项目：

<?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>
        
        
        <properties resource="application.properties"/>
        
        
    
        
        
        <context id="MysqlTables" targetRuntime="MyBatis3Simple" defaultModelType="flat">
            
            <property name="autoDelimitKeywords" value="true" />
            
            <property name="javaFileEncoding" value="utf-8" />
            
            <property name="beginningDelimiter" value="`" />
            <property name="endingDelimiter" value="`" />
    
            
            <property name="javaFormatter" value="org.mybatis.generator.api.dom.DefaultJavaFormatter"/>
            
            <property name="xmlFormatter" value="org.mybatis.generator.api.dom.DefaultXmlFormatter"/>
            <plugin type="org.mybatis.generator.plugins.SerializablePlugin" />
    
            <plugin type="org.mybatis.generator.plugins.ToStringPlugin" />
    
            
            <commentGenerator >
                <property name="suppressAllComments" value="false"/>
                <property name="suppressDate" value="true" /> 
            </commentGenerator>
    
            
            <jdbcConnection driverClass="${spring.datasource.driver-class-name}" connectionURL="${spring.datasource.url}" userId="${spring.datasource.username}" password="${spring.datasource.password}" />
            
            <javaTypeResolver>
                
                <property name="forceBigDecimals" value="false"/>
            </javaTypeResolver>
    
            
            <javaModelGenerator targetPackage="com.dalaoyang.entity" targetProject="${mybatis.project}" >
                <property name="enableSubPackages" value="false"/>
                <property name="trimStrings" value="true"/>
            </javaModelGenerator>
            
            <sqlMapGenerator targetPackage="mapper" targetProject="${mybatis.resources}" >
                <property name="enableSubPackages" value="false" />
            </sqlMapGenerator>
            
            <javaClientGenerator targetPackage="com.dalaoyang.dao" targetProject="${mybatis.project}" type="XMLMAPPER" >
                <property name="enableSubPackages" value="false" />
            </javaClientGenerator>
            
            <table tableName="user" enableCountByExample="true" enableUpdateByExample="true" enableDeleteByExample="true" enableSelectByExample="true" selectByExampleQueryId="true">
                <property name="useActualColumnNames" value="false" />
                
                <generatedKey column="id" sqlStatement="Mysql" identity="true" />
            </table>
            <table tableName="book" enableCountByExample="true" enableUpdateByExample="true" enableDeleteByExample="true" enableSelectByExample="true" selectByExampleQueryId="true">
                <property name="useActualColumnNames" value="false" />
                
                <generatedKey column="id" sqlStatement="Mysql" identity="true" />
            </table>
        </context>
    </generatorConfiguration>

### 配置application.properties ###

配置项目的application.properties，其中数据库信息，Mapper地址之前都有过介绍，具体SpringBoot-Mybatis配置可以参考：  
[《SpringBoot+Mybatis+MySql学习》][SpringBoot_Mybatis_MySql]

本文配置如下：

## mapper xml 文件地址
    mybatis.mapper-locations=classpath*:mapper/*Mapper.xml
    
    ##数据库url
    spring.datasource.url=jdbc:mysql://localhost:3306/test?characterEncoding=utf8&useSSL=false
    ##数据库用户名
    spring.datasource.username=root
    ##数据库密码
    spring.datasource.password=123456
    ##数据库驱动
    spring.datasource.driver-class-name=com.mysql.jdbc.Driver
    
    
    #Mybatis Generator configuration
    #dao类和实体类的位置
    mybatis.project =src/main/java
    #mapper文件的位置
    mybatis.resources=src/main/resources

到这里其实配置就完成了，可以体验Mybatis-Generator插件的优点了，在右侧Maven处点击如图所示位置，如图：

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点击完成后，可以看到Mapper，dao，实体类都已经创建好了，如图：

![3][]

创建完成会给我生成几个默认的建当方法，如UserMapper代码如下：

package com.dalaoyang.dao;
    
    import com.dalaoyang.entity.User;
    import org.apache.ibatis.annotations.Mapper;
    
    import java.util.List;
    
    public interface UserMapper {
        /**
         * This method was generated by MyBatis Generator.
         * This method corresponds to the database table user
         *
         * @mbggenerated
         */
        int deleteByPrimaryKey(Long id);
    
        /**
         * This method was generated by MyBatis Generator.
         * This method corresponds to the database table user
         *
         * @mbggenerated
         */
        int insert(User record);
    
        /**
         * This method was generated by MyBatis Generator.
         * This method corresponds to the database table user
         *
         * @mbggenerated
         */
        User selectByPrimaryKey(Long id);
    
        /**
         * This method was generated by MyBatis Generator.
         * This method corresponds to the database table user
         *
         * @mbggenerated
         */
        List<User> selectAll();
    
        /**
         * This method was generated by MyBatis Generator.
         * This method corresponds to the database table user
         *
         * @mbggenerated
         */
        int updateByPrimaryKey(User record);
    }

UserMapper.xml代码如下：

<?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.dalaoyang.dao.UserMapper" >
      <resultMap id="BaseResultMap" type="com.dalaoyang.entity.User" >
        
        <id column="id" property="id" jdbcType="BIGINT" />
        <result column="user_name" property="userName" jdbcType="VARCHAR" />
        <result column="user_password" property="userPassword" jdbcType="VARCHAR" />
      </resultMap>
      <delete id="deleteByPrimaryKey" parameterType="java.lang.Long" >
        
        delete from user
        where id = #{id,jdbcType=BIGINT}
      </delete>
      <insert id="insert" parameterType="com.dalaoyang.entity.User" >
        
        <selectKey resultType="java.lang.Long" keyProperty="id" order="AFTER" >
          SELECT LAST_INSERT_ID()
        </selectKey>
        insert into user (user_name, user_password)
        values (#{userName,jdbcType=VARCHAR}, #{userPassword,jdbcType=VARCHAR})
      </insert>
      <update id="updateByPrimaryKey" parameterType="com.dalaoyang.entity.User" >
        
        update user
        set user_name = #{userName,jdbcType=VARCHAR},
          user_password = #{userPassword,jdbcType=VARCHAR}
        where id = #{id,jdbcType=BIGINT}
      </update>
      <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Long" >
        
        select id, user_name, user_password
        from user
        where id = #{id,jdbcType=BIGINT}
      </select>
      <select id="selectAll" resultMap="BaseResultMap" >
        
        select id, user_name, user_password
        from user
      </select>
    </mapper>

## 测试使用 ##

### 新增测试方法 ###

在UserMapper上加入注解@Mapper表明是持久化映射层，启动类上加入注解@RestController进行测试，这里简单调用一个查询所有的方法selectAll，启动类代码如下:

@SpringBootApplication
    @RestController
    public class SpringbootGeneratorApplication {
    
        @Autowired
        private UserMapper userMapper;
    
        @GetMapping("/findAll")
        public List<User> findAll(){
            return userMapper.selectAll();
        }
    
        public static void main(String[] args) {
            SpringApplication.run(SpringbootGeneratorApplication.class, args);
        }
    }

### 运行测试 ###

运行项目，浏览器访问localhost:8080/findAll如图所示：

![4][]

源码下载 ：[大老杨码云][Link 1]

[1]: /images/20220514/2b88f46632464d659a43fbd36132eff6.png
[http_www.mybatis.org_generator_index.html]: http://www.mybatis.org/generator/index.html
[SpringBoot_Mybatis_MySql]: https://www.jianshu.com/p/8b545a537fd0
[2]: /images/20220514/dab26edb7e1e4330a531025ca99e8666.png
[3]: /images/20220514/7f31a2f9ef20426180fecaed88ddd890.png
[4]: /images/20220514/bf52901e3ac04b76a6b743cb27a8e1b3.png
[Link 1]: https://gitee.com/dalaoyang/springboot_learn