# Mybatis code generator use (generate the relevant code of a table)

Use of Mybatis code generator (generate related code for a table)

• In fact, MyBatis Generator can achieve all the functions, just write it in order to learn

Introduce dependencies

<dependencies>
    <!-- Mybaits 生成器代码 -->
    <dependency>
        <groupId>org.mybatis.generator</groupId>
        <artifactId>mybatis-generator-core</artifactId>
        <version>1.3.4</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.39</version>
    </dependency>
</dependencies>

Generator main class

• Generator.java

public class Generator {
    
    

    private static Logger logger = Logger.getLogger(String.valueOf(Generator.class));

    public static void main(String[] args) {
    
    
        logger.info("=====>准备生成代码");
        String table = null;
        String file = null;
        try {
    
    
            System.out.println("请输入表名：");
            InputStream in = System.in;
            Scanner scanner = new Scanner(in);
            table = scanner.next();
            logger.info("=====>表名称为："+table);
            System.out.println("请输入数据库配置文件名：");
            file = scanner.next();
            logger.info("=====>文件位置为："+file);
            scanner.close();
            in.close();
        } catch (IOException e) {
    
    
            e.printStackTrace();
        }

        String test="D:\\TrainingCode\\JavaTraining\\mybatis-generator\\src\\main\\resources\\generator\\generatorConfig.xml";
        String test1 = "security_algorithm";

        List<String> warnings = new ArrayList<>();
        // 覆盖
        boolean overwrite = true;
        // 给出generatorConfig.xml文件的位置
        logger.info("=====>读到数据库配置文件位置");

        File configFile = new File(file);
        if(!configFile.exists()){
    
    
            logger.info("=====>文件不存在！");
            return;
        }
        ConfigurationParser cp = new ConfigurationParser(warnings);
        try {
    
    
            Configuration config = cp.parseConfiguration(configFile);

            if(Objects.nonNull(table) && table.length()>0) {
    
    
                // 定义要拿的库和表
                List<Context> contexts = config.getContexts();
                Context context = contexts.get(0);
                List<TableConfiguration> tableConfigurations = context.getTableConfigurations();
                TableConfiguration tableConfiguration = tableConfigurations.get(0);
                tableConfiguration.setTableName(table);
                context.addTableConfiguration(tableConfiguration);
            }

            DefaultShellCallback callback = new DefaultShellCallback(overwrite);
            MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
            myBatisGenerator.generate(null);
            logger.info("生成代码完成！");
        } catch (Exception e) {
    
    
           logger.info("=====>代码生成出错："+e.getMessage());
        }
    }
}

Generate code comment configuration class

public class MyCommentGenerator implements CommentGenerator {
    
    


    private Properties properties = new Properties();
    /**
     * 抑制日期  默认false：不抑制
     */
    private boolean suppressDate = false;

    /**
     * 抑制注释 默认false：不抑制
     */
    private boolean suppressAllComments = false;

    /**
     * 显示数据库comments 默认false：不显示
     */
    private boolean addRemarkComments = false;
    /**
     * 日期格式
     */
    private SimpleDateFormat dateFormat;

    public MyCommentGenerator() {
    
    
        super();
        dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    }


    /**
     * 读取配置文件
     *
     * @author LiDong
     * @date 2020/12/10
     * @param '[properties]'
     * @return void
     */
    @Override
    public void addConfigurationProperties(Properties properties) {
    
    
        this.properties.putAll(properties);
        this.suppressDate = StringUtility.isTrue(properties.getProperty("suppressDate"));
        this.suppressAllComments = StringUtility.isTrue(properties.getProperty("suppressAllComments"));
        this.addRemarkComments = StringUtility.isTrue(properties.getProperty("addRemarkComments"));
        String dateFormatString = properties.getProperty("dateFormat");
        if (StringUtility.stringHasValue(dateFormatString)) {
    
    
            this.dateFormat = new SimpleDateFormat(dateFormatString);
        }

    }

    /**
     * 日期格式化
     *
     * @author LiDong
     * @date 2020/12/10
     * @param '[]'
     * @return java.lang.String
     */
    protected String getDateString() {
    
    
        if (this.suppressDate) {
    
    
            return null;
        } else {
    
    
            return this.dateFormat != null ? this.dateFormat.format(new Date()) : (new Date()).toString();
        }
    }

    /**
     * 创建的数据表对应的类添加的注释
     *
     * @author LiDong
     * @date 2020/12/10
     * @param '[topLevelClass, introspectedTable]'
     * @return void
     */
    @Override
    public void addModelClassComment(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {
    
    
        if (!this.suppressAllComments) {
    
    
            topLevelClass.addJavaDocLine("/**");
            topLevelClass.addJavaDocLine(" * @author LiDong");
            topLevelClass.addJavaDocLine(" * @version 1.0.0 ");
            topLevelClass.addJavaDocLine(" * @description MyBatis Generator 自动创建,对应数据表为：" + introspectedTable.getFullyQualifiedTable());
            topLevelClass.addJavaDocLine(" * @createTime " + this.getDateString());
            topLevelClass.addJavaDocLine(" */");
        }
    }

    @Override
    public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable) {
    
    

    }

    @Override
    public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable, boolean b) {
    
    

    }

    @Override
    public void addEnumComment(InnerEnum innerEnum, IntrospectedTable introspectedTable) {
    
    

    }

    /**
     * 生成字段的注释
     *
     * @author LiDong
     * @date 2020/12/10
     * @param '[field, introspectedTable, introspectedColumn]'
     * @return void
     */
    @Override
    public void addFieldComment(Field field, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) {
    
    
        if (!this.suppressAllComments) {
    
    
            // 注释开始的地方
            field.addJavaDocLine("/**");
            String remarks = introspectedColumn.getRemarks();
            // 开启注释，并且数据库中comment有值
            if (Objects.nonNull(remarks) && remarks.length()>0) {
    
    
                // 通过换行符分割 System.getProperty("line.separator")：换行符 ，屏蔽了 Windows和Linux的区别
                String[] remarkLines = remarks.split(System.getProperty("line.separator"));
                int length = remarkLines.length;
                // 如果有多行，就换行显示
                for (int i = 0; i < length; i++) {
    
    
                    String remarkLine = remarkLines[i];
                    field.addJavaDocLine(" * " + remarkLine);
                }
            }else {
    
    
                field.addJavaDocLine(" * "+field.getName());
            }
            // 注释结束
            field.addJavaDocLine(" */");
        }
    }

    @Override
    public void addFieldComment(Field field, IntrospectedTable introspectedTable) {
    
    

    }

    /**
     * xxxMapper接口和xxxExample类方法注解
     *
     * @author LiDong
     * @date 2020/12/10
     * @param '[method, introspectedTable]'
     * @return void
     */
    @Override
    public void addGeneralMethodComment(Method method, IntrospectedTable introspectedTable) {
    
    
        if (!this.suppressAllComments) {
    
    
            method.addJavaDocLine("/**");
            method.addJavaDocLine(" * " + method.getName());
            List<Parameter> parameters = method.getParameters();
            parameters.forEach(parameter -> method.addJavaDocLine(" * @param " + parameter.getName()));
            // 如果有返回类型，添加@return
            String returnType = "void";
            if (!returnType.equals(method.getReturnType())) {
    
    
                method.addJavaDocLine(" * @return ");
            }
            method.addJavaDocLine(" */");
        }

    }

    @Override
    public void addJavaFileComment(CompilationUnit compilationUnit) {
    
    

    }

   /**
    * 数据库对应实体类的Getter方法注解
    *
    * @author LiDong
    * @date 2020/12/10
    * @param '[method, introspectedTable, introspectedColumn]'
    * @return void
    */
    @Override
    public void addGetterComment(Method method, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) {
    
    

    }

    /**
     * 数据库对应实体类的Setter方法注解
     *
     * @author LiDong
     * @date 2020/12/10
     * @param '[method, introspectedTable, introspectedColumn]'
     * @return void
     */
    @Override
    public void addSetterComment(Method method, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) {
    
    

    }

   /**
    * 生成xxMapper.XML文件的注释
    *
    * @author LiDong
    * @date 2020/12/10
    * @param '[xmlElement]'
    * @return void
    */
    @Override
    public void addComment(XmlElement xmlElement) {
    
    
    }

    @Override
    public void addRootComment(XmlElement xmlElement) {
    
    
    }
}

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>
    <context id="MySQLTables" targetRuntime="MyBatis3">
        <plugin type="org.mybatis.generator.plugins.EqualsHashCodePlugin"/>

        <commentGenerator type="mybatisgenerate.MyCommentGenerator"></commentGenerator>

        <!--  配置数据库链接信息          -->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/shop?useUnicode=yes&amp;characterEncoding=UTF-8&amp;useSSL=false"
                        userId="root"
                        password="0000">
        </jdbcConnection>

        <!-- 实体类位置       -->
        <javaModelGenerator targetPackage="com.li.domain" targetProject=".">
            <property name="enableSubPackages" value="true"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>

        <sqlMapGenerator targetPackage="com.li.mapper" targetProject=".">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>

        <javaClientGenerator type="XMLMAPPER" targetPackage="com.li.mapper" targetProject=".">
            <property name="enableSubPackages" value="true"/>
        </javaClientGenerator>

        <table schema="shop" tableName="" ></table>

    </context>
</generatorConfiguration>

use

• The jar packaging, java -jar start to enter the appropriate parameters
  -