官网说明

1、mybatisplus 3.X版本

<!-- 代码生成工具依赖【开始】 -->
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus</artifactId>
			<version>3.3.2</version>
		</dependency>

		<dependency>
			<groupId>org.junit.jupiter</groupId>
			<artifactId>junit-jupiter-engine</artifactId>
		</dependency>

		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus-generator</artifactId>
			<version>3.3.2</version>
		</dependency>
		<dependency>
			<groupId>org.apache.velocity</groupId>
			<artifactId>velocity-engine-core</artifactId>
			<version>2.2</version>
		</dependency>
		<!-- 代码生成工具依赖【结束】 -->   

package com.JoyceYoung.GenerateCode;

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.config.DataSourceConfig;
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.rules.NamingStrategy;
import org.junit.jupiter.api.Test;

/**
 * <p>
 * 生成代码
 * </p>
 *
 * @author K神
 * @date 2017/12/18
 */
public class GeneratorServiceEntity {


//        private String dbType = "oracle";
    private String dbType = "mysql";
    private String dbUrl = "";
    private String driverName = "";
    private String username = "";
    private String password = "";

    public GeneratorServiceEntity() {
        if (dbType.equals("mysql")) {
            this.dbUrl = "jdbc:mysql://localhost:3306/test?serverTimezone=UTC";
            this.driverName = "com.mysql.cj.jdbc.Driver";
            this.username = "XXXX";
            this.password = "XXXX";
        } else if (dbType.equals("oracle")) {
            this.dbUrl = "jdbc:oracle:thin:@localhost:1521:ORCL";
            this.driverName = "oracle.jdbc.OracleDriver";
            this.username = "XXXX";
            this.password = "XXXX";
        }

    }


    @Test
    public void generateCode() {
        String packageName = "com.demo.user";
        boolean serviceNameStartWithI = true;//user -> UserService, 设置成true: user -> IUserService
        generateByTables(serviceNameStartWithI, packageName, "USER");// oracle 的时候，表名要大写
    }

    private void generateByTables(boolean serviceNameStartWithI, String packageName, String... tableNames) {
        GlobalConfig config = new GlobalConfig();
        DataSourceConfig dataSourceConfig = new DataSourceConfig();
        if (dbType.equals("oracle")) {
            dataSourceConfig.setDbType(DbType.ORACLE);
        } else if (dbType.equals("mysql")) {
            dataSourceConfig.setDbType(DbType.MYSQL);
        }
        dataSourceConfig
                .setUrl(dbUrl)
                .setUsername(username)
                .setPassword(password)
                .setDriverName(driverName);
        StrategyConfig strategyConfig = new StrategyConfig();
        strategyConfig
                .setCapitalMode(true)
                .setEntityLombokModel(false)
                .setNaming(NamingStrategy.underline_to_camel)
                .setEntityTableFieldAnnotationEnable(true)//实体属性上添加表字段映射
                .setInclude(tableNames);//修改替换成你需要的表名，多个表名传数组
        config.setActiveRecord(false)
                .setAuthor("名字")
                .setOutputDir("/Users/……………………")
                .setFileOverride(true);
        if (!serviceNameStartWithI) {
            config.setServiceName("%sService");
        }
        new AutoGenerator().setGlobalConfig(config)
                .setDataSource(dataSourceConfig)
                .setStrategy(strategyConfig)
                .setPackageInfo(
                        new PackageConfig()
                                .setParent(packageName)
                                .setController("web")
                                .setEntity("pojo.entity")
                ).execute();
    }

    private void generateByTables(String packageName, String... tableNames) {
        generateByTables(true, packageName, tableNames);
    }
}

2、mybatisplus 2.X版本

官网参考

<!-- 代码生成工具依赖【开始】 -->
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus</artifactId>
			<version>2.3.3</version>
		</dependency>

		<dependency>
			<groupId>org.junit.jupiter</groupId>
			<artifactId>junit-jupiter-engine</artifactId>
		</dependency>

		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus-generate</artifactId>
			<version>2.3.3</version>
		</dependency>

		<dependency>
			<groupId>org.apache.velocity</groupId>
			<artifactId>velocity-engine-core</artifactId>
			<version>2.2</version>
		</dependency>
		<!-- 代码生成工具依赖【结束】 -->

package com.JoyceYoung.GenerateCode;


import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.config.DataSourceConfig;
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.rules.DbType;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import org.junit.jupiter.api.Test;

/**
 * <p>
 * 生成代码
 * </p>
 *
 * @author K神
 * @date 2017/12/18
 */
public class GeneratorServiceEntity {


//        private String dbType = "oracle";
    private String dbType = "mysql";
    private String dbUrl = "";
    private String driverName = "";
    private String username = "";
    private String password = "";

    public GeneratorServiceEntity() {
       if (dbType.equals("mysql")) {
            this.dbUrl = "jdbc:mysql://localhost:3306/test?serverTimezone=UTC";
            this.driverName = "com.mysql.cj.jdbc.Driver";
            this.username = "XXXX";
            this.password = "XXXX";
        } else if (dbType.equals("oracle")) {
            this.dbUrl = "jdbc:oracle:thin:@localhost:1521:ORCL";
            this.driverName = "oracle.jdbc.OracleDriver";
            this.username = "XXXX";
            this.password = "XXXX";
        }


    }


    @Test
    public void generateCode() {
  		String packageName = "com.demo.user";
        boolean serviceNameStartWithI = true;//user -> UserService, 设置成true: user -> IUserService
        generateByTables(serviceNameStartWithI, packageName, "USER");// oracle 的时候，表名要大写
    }

    private void generateByTables(boolean serviceNameStartWithI, String packageName, String... tableNames) {
        GlobalConfig config = new GlobalConfig();
        DataSourceConfig dataSourceConfig = new DataSourceConfig();
        if (dbType.equals("oracle")) {
            dataSourceConfig.setDbType(DbType.ORACLE);
        } else if (dbType.equals("mysql")) {
            dataSourceConfig.setDbType(DbType.MYSQL);
        }
        dataSourceConfig
                .setUrl(dbUrl)
                .setUsername(username)
                .setPassword(password)
                .setDriverName(driverName);
        StrategyConfig strategyConfig = new StrategyConfig();
        strategyConfig.setCapitalMode(true)
                .setEntityLombokModel(true)
                .setDbColumnUnderline(true)
                .setNaming(NamingStrategy.underline_to_camel)
                .entityTableFieldAnnotationEnable(true)//实体属性上添加表字段映射
                .setInclude(tableNames);//修改替换成你需要的表名，多个表名传数组
        config.setActiveRecord(false)
                .setAuthor("名字")
                .setOutputDir("/Users/………………")
                .setFileOverride(true);
        if (!serviceNameStartWithI) {
            config.setServiceName("%sService");
        }
        new AutoGenerator().setGlobalConfig(config)
                .setDataSource(dataSourceConfig)
                .setStrategy(strategyConfig)
                .setPackageInfo(
                        new PackageConfig()
                                .setParent(packageName)
                                .setController("web")
                                .setEntity("pojo.entity")
                ).execute();
    }

    private void generateByTables(String packageName, String... tableNames) {
        generateByTables(true, packageName, tableNames);
    }
}