1.先要引入依賴包

<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus</artifactId>
			<version>3.0.5</version>
		</dependency>
		<!-- velocity 模板引擎, 預設 -->
		<dependency>
			<groupId>org.apache.velocity</groupId>
			<
 
artifactId>velocity-engine-core</artifactId>
			<version>2.0</version>
		</dependency>

		<!-- freemarker 模板引擎 -->
		<dependency>
			<groupId>org.freemarker</groupId>
			<artifactId>freemarker</artifactId>
			<version>2.3.28</version>
 

		</dependency>
		<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>5.1.13</version>
		</dependency>
		<!-- https://mvnrepository.
 
com/artifact/org.springframework/spring-core -->
		<dependency>
		    <groupId>org.springframework</groupId>
		    <artifactId>spring-core</artifactId>
		    <version>4.3.20.RELEASE</version>
		</dependency>

2.建立程式碼生成器

package cn.ps;

import java.util.ArrayList;
import java.util.List;

import com.baomidou.mybatisplus.core.toolkit.StringPool;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.InjectionConfig;
import com.baomidou.mybatisplus.generator.config.DataSourceConfig;
import com.baomidou.mybatisplus.generator.config.FileOutConfig;
import com.baomidou.mybatisplus.generator.config.GlobalConfig;
import com.baomidou.mybatisplus.generator.config.PackageConfig;
import com.baomidou.mybatisplus.generator.config.StrategyConfig;
import com.baomidou.mybatisplus.generator.config.TemplateConfig;
import com.baomidou.mybatisplus.generator.config.po.TableInfo;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;

public class Demo {

	public static void main(String[] args) {
		AutoGenerator mpg = new AutoGenerator();

        // 全域性配置
        GlobalConfig gc = new GlobalConfig();
        final String projectPath = System.getProperty("user.dir");
        //你要建立的檔案放在哪個包下面
        gc.setOutputDir(projectPath + "/src/main/java");
        gc.setAuthor("張三");
        gc.setOpen(false);
        mpg.setGlobalConfig(gc);

        // 資料來源配置
        DataSourceConfig dsc = new DataSourceConfig();
        dsc.setUrl("jdbc:mysql://localhost:3306/unit02?useUnicode=true&useSSL=false&characterEncoding=utf8");
        // dsc.setSchemaName("public");
        dsc.setDriverName("com.mysql.jdbc.Driver");
        dsc.setUsername("root");
        dsc.setPassword("ps123456");
        mpg.setDataSource(dsc);

        // 包配置
        PackageConfig pc = new PackageConfig();
        //設定包名
        final String modue="MyBatis";
        pc.setModuleName(modue);
        pc.setParent("com.ps.test");
        mpg.setPackageInfo(pc);

        // 自定義配置
        InjectionConfig cfg = new InjectionConfig() {
            @Override
            public void initMap() {
                // to do nothing
            }
        };
        List<FileOutConfig> focList = new ArrayList();
        focList.add(new FileOutConfig("/templates/mapper.xml.ftl") {
            @Override
            public String outputFile(TableInfo tableInfo) {
                // 自定義輸入檔名稱
                return projectPath + "/src/main/resources/mapper/" + modue
                        + "/" + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;
            }
        });
        cfg.setFileOutConfigList(focList);
        mpg.setCfg(cfg);
        mpg.setTemplate(new TemplateConfig().setXml(null));

        // 策略配置
        StrategyConfig strategy = new StrategyConfig();
        strategy.setNaming(NamingStrategy.underline_to_camel);
        strategy.setColumnNaming(NamingStrategy.underline_to_camel);
        //strategy.setSuperEntityClass("com.baomidou.ant.common.BaseEntity");
        //設定是否使用小辣椒框架
        strategy.setEntityLombokModel(true);
        strategy.setRestControllerStyle(true);
        //strategy.setSuperControllerClass("com.baomidou.ant.common.BaseController");
        //設定要建立的資料庫的表名
        strategy.setInclude("emp1");
        strategy.setSuperEntityColumns("id");
        strategy.setControllerMappingHyphenStyle(true);
        strategy.setTablePrefix(pc.getModuleName() + "_");
        mpg.setStrategy(strategy);
        mpg.setTemplateEngine(new FreemarkerTemplateEngine());
        mpg.execute();
	}

}