mybatis-generator支持java bean添加数据库字段注释(mysql和sqlserver)

一、依赖

<dependency>
    <groupId>org.mybatis.generator</groupId>
    <artifactId>mybatis-generator-core</artifactId>
    <version>1.3.7</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.15</version>
</dependency>
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.4.0</version>
</dependency>

二、配置

1. generatorConfig.xml

<?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="generator.properties"/>
    <context id="MySqlContext" targetRuntime="MyBatis3" defaultModelType="flat">
        <property name="beginningDelimiter" value="`"/>
        <property name="endingDelimiter" value="`"/>
        <property name="javaFileEncoding" value="UTF-8"/>
        <!-- 为模型生成序列化方法-->
        <plugin type="org.mybatis.generator.plugins.SerializablePlugin"/>
        <!-- 为生成的Java模型创建一个toString方法 -->
        <plugin type="org.mybatis.generator.plugins.ToStringPlugin"/>
        <!--生成mapper.xml时覆盖原文件-->
        <plugin type="org.mybatis.generator.plugins.UnmergeableXmlMappersPlugin" />
        <!--可以自定义生成model的代码注释-->
        <commentGenerator type="com.example.CommentGenerator">
            <!-- 是否去除自动生成的注释 true：是 ： false:否 -->
            <property name="suppressAllComments" value="true"/>
            <property name="suppressDate" value="true"/>
            <property name="addRemarkComments" value="true"/>
        </commentGenerator>
        <!--配置数据库连接-->
        <jdbcConnection driverClass="${jdbc.driverClass}"
                        connectionURL="${jdbc.url}"
                        userId="${jdbc.userId}"
                        password="${jdbc.password}">
            <!--解决mysql驱动升级到8.0后不生成指定数据库代码的问题-->
            <property name="nullCatalogMeansCurrent" value="true" />
        </jdbcConnection>
        <!--指定生成model的路径-->
        <javaModelGenerator targetPackage="com.fang.industry.service.decotation.model" targetProject="src\main\java"/>
        <!--指定生成mapper.xml的路径-->
        <sqlMapGenerator targetPackage="com.fang.industry.service.decotation.mapper" targetProject="src\main\java"/>
        <!--指定生成mapper接口的的路径-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.fang.industry.service.decotation.dao"
                             targetProject="src\main\java"/>
        <!--生成全部表tableName设为%-->
        <table tableName="t_order" domainObjectName="Order" mapperName="OrderMapper" enableCountByExample="false"
               enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false"
               selectByExampleQueryId="false" ></table>
    </context>
</generatorConfiguration>

2. generator.properties

jdbc.driverClass=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/db01?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai&useSSL=false
jdbc.userId=root
jdbc.password=123456

三、自定义实现类

public class CommentGenerator extends DefaultCommentGenerator {
    private boolean addRemarkComments = false;
    private static final String EXAMPLE_SUFFIX="Example";
//    private static final String API_MODEL_PROPERTY_FULL_CLASS_NAME="io.swagger.annotations.ApiModelProperty";

    /**
     * 设置用户配置的参数
     */
    @Override
    public void addConfigurationProperties(Properties properties) {
        super.addConfigurationProperties(properties);
        this.addRemarkComments = StringUtility.isTrue(properties.getProperty("addRemarkComments"));
    }

    /**
     * 给字段添加注释
     */
    @Override
    public void addFieldComment(Field field, IntrospectedTable introspectedTable,
                                IntrospectedColumn introspectedColumn) {
        String remarks = introspectedColumn.getRemarks();
        //根据参数和备注信息判断是否添加备注信息
        if(addRemarkComments&&StringUtility.stringHasValue(remarks)){
            //数据库中特殊字符需要转义
            if(remarks.contains("\"")){
                remarks = remarks.replace("\"","'");
            }
            addFieldJavaDoc(field, remarks);
//            //给model的字段添加swagger注解
//            field.addJavaDocLine("@ApiModelProperty(value = \""+remarks+"\")");
        }
    }

    /**
     * 给model的字段添加注释
     */
    private void addFieldJavaDoc(Field field, String remarks) {
        field.addJavaDocLine("//"+ remarks);
    }

    @Override
    public void addJavaFileComment(CompilationUnit compilationUnit) {
        super.addJavaFileComment(compilationUnit);
        //只在model中添加swagger注解类的导入
//        if(!compilationUnit.isJavaInterface()&&!compilationUnit.getType().getFullyQualifiedName().contains(EXAMPLE_SUFFIX)){
//            compilationUnit.addImportedType(new FullyQualifiedJavaType(API_MODEL_PROPERTY_FULL_CLASS_NAME));
//        }
    }
}

四、代码生成入口

public class Generator {
    public static void main(String[] args) throws Exception {
        //MBG 执行过程中的警告信息
        List<String> warnings = new ArrayList<String>();
        //当生成的代码重复时，覆盖原代码
        boolean overwrite = true;
        //读取我们的 MBG 配置文件
        InputStream is = Generator.class.getResourceAsStream("/generatorConfig.xml");
        ConfigurationParser cp = new ConfigurationParser(warnings);
        Configuration config = cp.parseConfiguration(is);
        is.close();

        DefaultShellCallback callback = new DefaultShellCallback(overwrite);
        //创建 MBG
        MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
        //执行生成代码
        myBatisGenerator.generate(null);
        //输出警告信息
        for (String warning : warnings) {
            System.out.println(warning);
        }
    }
}

五、补充

添加支持sqlserver库javabean对象属性上添加注释(上面贴出的代码是不支持的)的相关代码，源码地址: https://gitee.com/junlin1991/mybatis-generator