java使用mybatis-generator实现自动生成model、dao、xml

方式一

pom中添加插件

            <plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <version>1.3.1</version>
                <dependencies>
                    <dependency>
                        <groupId>mysql</groupId>
                        <artifactId>mysql-connector-java</artifactId>
                        <version>8.0.21</version>
                    </dependency>
                </dependencies>
            </plugin>

在src/main/resources目录创建`generatorConfig.xml`文件

<?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>
    <!-- 数据库驱动:选择你的本地硬盘上面的数据库驱动包-->
    <classPathEntry  location="/Users/grant/usr/local/repository/mysql/mysql-connector-java/8.0.26"/>
    <context id="DB2Tables"  targetRuntime="MyBatis3">
        <commentGenerator>
            <property name="suppressDate" value="true"/>
            <!-- 是否去除自动生成的注释 true：是 ： false:否 -->
            <property name="suppressAllComments" value="true"/>
        </commentGenerator>
        <!--数据库链接URL，用户名、密码 -->
        <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver" connectionURL="jdbc:mysql://ip:port/database_name?characterEncoding=utf8"
                        userId="root" password="root">
        </jdbcConnection>
        <javaTypeResolver>
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>

        <!-- 生成模型的包名和位置-->
        <javaModelGenerator targetPackage="com.22.bat.model" targetProject="src/main/java">
            <property name="enableSubPackages" value="true"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>

        <!-- 生成映射文件的包名和位置 resources下的目录-->
        <sqlMapGenerator targetPackage="sqlmap" targetProject="src/main/resources">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>

        <!-- 生成DAO的包名和位置-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.22.bat.dao" targetProject="src/main/java">
            <property name="enableSubPackages" value="true"/>
        </javaClientGenerator>

        <!-- 要生成的表 tableName是数据库中的表名或视图名 domainObjectName是实体类名-->
        <table tableName="user_info" domainObjectName="UserInfo" enableCountByExample="false" enableUpdateByExample="false"
               enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>
<!--        <table tableName="user" domainObjectName="user" enableCountByExample="false" enableUpdateByExample="false"-->
<!--               enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>-->
<!--        <table tableName="order" domainObjectName="order" enableCountByExample="false" enableUpdateByExample="false"-->
<!--               enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>-->
    </context>
</generatorConfiguration>

idea右侧maven下该模块插件点击生成

 方式二

在src/main/resources目录创建`generatorConfig.xml`文件

<!DOCTYPE generatorConfiguration PUBLIC
        "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
    <!-- MyBatis3Simple风格 -->
    <context id="simple" targetRuntime="MyBatis3Simple">

        <property name="javaFileEncoding" value="UTF-8"/>
        <!--生成mapper.xml时覆盖原文件-->
        <plugin type="org.mybatis.generator.plugins.UnmergeableXmlMappersPlugin"/>

        <commentGenerator>
            <!-- 是否去除自动生成的注释 true：是 ： false:否。 自动生成注释太啰嗦，可以编码扩展CommentGenerator -->
            <property name="suppressAllComments" value="true"/>
        </commentGenerator>

        <!-- 数据库连接 -->
        <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/db_book?useUnicode=true&amp;characterEncoding=utf8&amp;tinyInt1isBit=true&amp;serverTimezone=UTC"
                        userId="root" password="root">
            <!-- 设置为true就只读取db_book下的表, 否则会优先读取到mysql的user表  -->
            <property name="nullCatalogMeansCurrent" value="true"/>
        </jdbcConnection>

        <!-- 生成PO的包名和位置 -->
        <javaModelGenerator targetPackage="org.tg.book.dal.po.mbg" targetProject="src/main/java"/>

        <!-- 生成XML映射文件的包名和位置 -->
        <sqlMapGenerator targetPackage="org.tg.book.dal.mapper.mbg" targetProject="src/main/resources"/>

        <!-- 生成Mapper接口的包名和位置 -->
        <javaClientGenerator type="XMLMAPPER" targetPackage="org.tg.book.dal.mapper.mbg" targetProject="src/main/java"/>

        <!-- 要生成对应表配置 -->
        <table tableName="user" domainObjectName="User" >
            <!-- 自增主键列 -->
            <generatedKey column="id" sqlStatement="MYSQL" identity="true"/>
            <!-- tinyint映射为Integer -->
            <columnOverride column="role" javaType="Integer" jdbcType="TINYINT"/>
        </table>
    </context>
</generatorConfiguration>

简介版和强大版 只需要将 targetRuntime=“MyBatis3Simple” 修改为 targetRuntime=“MyBatis3”

将 targetRuntime=“MyBatis3” 修改为 targetRuntime=“MyBatis3DynamicSql”。 生成的代码是全注解风格的，也就不会生成UserMapper.xml和UserExample类，而是新生成了UserDynamicSqlSupport类。

<build>
    <resources>
        <resource>
            <directory>src/main/resources</directory>
            <filtering>true</filtering>
        </resource>
    </resources>
    <plugins>
        <plugin>
            <groupId>org.mybatis.generator</groupId>
            <artifactId>mybatis-generator-maven-plugin</artifactId>
            <version>1.3.7</version>
            <configuration>
                <verbose>true</verbose>
                <overwrite>true</overwrite>
            </configuration>
            <dependencies>
                <dependency>
                    <groupId>mysql</groupId>
                    <artifactId>mysql-connector-java</artifactId>
                    <version>8.0.21</version>
                </dependency>
            </dependencies>
        </plugin>
    </plugins>
</build>

<!--mybatis-dynamic-sql-->
<dependency>
    <groupId>org.mybatis.dynamic-sql</groupId>
    <artifactId>mybatis-dynamic-sql</artifactId>
    <version>1.1.4</version>
</dependency>