Appearance

mybatis-plus 3.5代码生成器 ​

参考：代码生成器配置旧 | MyBatis-Plus (baomidou.com)

引入依赖 ​

xml
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-generator</artifactId>
    <version>3.4.1</version>
</dependency>

生成工具类 ​

java
package com.lautrans.utils;

import com.baomidou.mybatisplus.core.exceptions.MybatisPlusException;
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.*;
import com.baomidou.mybatisplus.generator.config.po.TableInfo;
import com.baomidou.mybatisplus.generator.config.rules.DateType;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;
import org.apache.commons.lang3.StringUtils;

import java.util.*;

/**
 * @program: ct-server
 * @ClassName MpGenerateUtil
 * @author: liupengxiang
 * @create: 2023-06-13 16:55
 * @description: mp逆向工程
 * @Version 1.0
 **/
public class MpGenerateUtil {
    private static final String author = "lpx";
    private static final List<Module> modules = new ArrayList<>();
    private static Module currentModule;
    private static String projectPath = System.getProperty("user.dir")  + "/";

    static {
        modules.add(new Module("lautrans-admin","jdbc:mysql:///lautrans-blog?serverTimezone=Asia/Shanghai"));
        modules.add(new Module("lautrans-api","jdbc:mysql:///lautrans-blog?serverTimezone=Asia/Shanghai"));
    }
    /**
     * 读取控制台内容
     */
    public static String scanner(String tip) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入" + tip + "：");
        if (scanner.hasNext()) {
            String ipt = scanner.next();
            if (StringUtils.isNotBlank(ipt)) {
                return ipt;
            }
        }
        throw new MybatisPlusException("请输入正确的" + tip + "！");
    }
    public static int moduleCheck(Integer max) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入序号：");
        int i = scanner.nextInt();
        if (i > max) {
            System.out.println("请输入正确的序号！");
            return moduleCheck(max);
        }
        return i;
    }
    public static void modules() {
        System.out.println("------------------请要生成的选择模块--------------");
        for (int i = 0; i < modules.size(); i++) {
            System.out.println(i + "." + modules.get(i).moduleName);
        }
    }
    public static void main(String[] args) {
        modules();
        currentModule = modules.get(moduleCheck(modules.size() - 1));
        System.out.println("已选择模块:" + currentModule.moduleName);
        // 代码生成器
        AutoGenerator mpg = new AutoGenerator();
        // 全局配置
        GlobalConfig gc = new GlobalConfig();
        projectPath = projectPath + "/" + currentModule.moduleName;
        gc.setOutputDir(projectPath + "/src/main/java");
        //作者
        gc.setAuthor(author);
        //打开输出目录
        gc.setOpen(false);
        //xml开启 BaseResultMap
        gc.setBaseResultMap(true);
        //xml 开启BaseColumnList
        gc.setBaseColumnList(true);
        //日期格式，采用Date
        gc.setDateType(DateType.ONLY_DATE);
        mpg.setGlobalConfig(gc);
        // 数据源配置
        DataSourceConfig dsc = new DataSourceConfig();
        dsc.setUrl(currentModule.url);
        dsc.setDriverName("com.mysql.cj.jdbc.Driver");
        dsc.setUsername("root");
        dsc.setPassword("3014");
        mpg.setDataSource(dsc);
        // 包配置
        PackageConfig pc = new PackageConfig();
        pc.setParent("com.lautrans")
                .setEntity("entity")
                .setMapper("mapper")
                .setService("service")
                .setServiceImpl("service.impl")
                .setController("controller");
        mpg.setPackageInfo(pc);
        // 自定义配置
        InjectionConfig cfg = new InjectionConfig() {
            @Override
            public void initMap() {
                // to do nothing
                Map<String, Object> map = new HashMap<>();
                map.put("date1", "1.0.0");
                this.setMap(map);
            }
        };
        // 如果模板引擎是 freemarker
        String templatePath = "/templates/mapper.xml.ftl";
        // 自定义输出配置
        List<FileOutConfig> focList = new ArrayList<>();
        // 自定义配置会被优先输出
        focList.add(new FileOutConfig(templatePath) {
            @Override
            public String outputFile(TableInfo tableInfo) {
                // 自定义输出文件名 ， 如果你 Entity 设置了前后缀、此处注意 xml 的名称会跟着发生变化！！
                return projectPath + "/src/main/resources/mapper/" +
                        tableInfo.getEntityName() + "Mapper"
                        + StringPool.DOT_XML;
            }
        });
        cfg.setFileOutConfigList(focList);
        mpg.setCfg(cfg);
        // 配置模板
        TemplateConfig templateConfig = new TemplateConfig()
                .setEntity("templates/entity.java")
                .setMapper("templates/mapper.java")
                .setService("templates/service.java")
                .setServiceImpl("templates/serviceImpl.java")
                .setController("templates/controller.java");
        templateConfig.setXml(null);
        mpg.setTemplate(templateConfig);
        // 策略配置
        StrategyConfig strategy = new StrategyConfig();
        //数据库表映射到实体的命名策略
        strategy.setNaming(NamingStrategy.underline_to_camel);
        //数据库表字段映射到实体的字段名
        strategy.setEntityTableFieldAnnotationEnable(true);
        //数据库表字段映射到实体的命名策略
        strategy.setColumnNaming(NamingStrategy.underline_to_camel);
        //lombok模型
        strategy.setEntityLombokModel(true);
        //生成 @RestController 控制器
        strategy.setRestControllerStyle(true);
        strategy.setControllerMappingHyphenStyle(false);
        strategy.setInclude(scanner("表名，多个英文逗号分割").split(","));
        //表前缀
        mpg.setStrategy(strategy);
        mpg.setTemplateEngine(new FreemarkerTemplateEngine());
        mpg.execute();
    }
    static class Module {
        protected String moduleName;
        protected String url;
        Module(String moduleName,String url) {
            this.moduleName = moduleName;
            this.url = url;
        }

        public String getModuleName() {
            return moduleName;
        }

        public void setModuleName(String moduleName) {
            this.moduleName = moduleName;
        }

        public String getUrl() {
            return url;
        }

        public void setUrl(String url) {
            this.url = url;
        }

        @Override
        public String toString() {
            return "Module{" +
                    "moduleName='" + moduleName + '\'' +
                    ", url='" + url + '\'' +
                    '}';
        }
    }
}

自定义模板 ​

引入模板freemarker引擎依赖

xml
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-freemarker</artifactId>
</dependency>

模板 ​

controller.java.ftl

text
package ${package.Controller};


import org.springframework.web.bind.annotation.RequestMapping;

<#if restControllerStyle>
import org.springframework.web.bind.annotation.RestController;
<#else>
import org.springframework.stereotype.Controller;
</#if>
<#if superControllerClassPackage??>
import ${superControllerClassPackage};
</#if>

/**
 * <p>
 * ${table.comment!} 前端控制器
 * </p>
 *
 * @author ${author}
 * @since ${date}
 */
<#if restControllerStyle>
@RestController
<#else>
@Controller
</#if>
@RequestMapping("<#if package.ModuleName?? && package.ModuleName != "">/${package.ModuleName}</#if>/<#if controllerMappingHyphenStyle??>${controllerMappingHyphen}<#else>${table.entityPath}</#if>")
<#if kotlin>
class ${table.controllerName}<#if superControllerClass??> : ${superControllerClass}()</#if>
<#else>
<#if superControllerClass??>
public class ${table.controllerName} extends ${superControllerClass} {
<#else>
public class ${table.controllerName} {
</#if>

}
</#if>

entity.java.ftl

text
package ${package.Entity};

<#list table.importPackages as pkg>
import ${pkg};
</#list>
<#if swagger2>
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
</#if>
<#if entityLombokModel>
import lombok.Data;
import lombok.EqualsAndHashCode;
    <#if chainModel>
import lombok.experimental.Accessors;
    </#if>
</#if>

/**
 * <p>
 * ${table.comment!}
 * </p>
 *
 * @author ${author}
 * @since ${date}
 */
<#if entityLombokModel>
@Data
    <#if superEntityClass??>
@EqualsAndHashCode(callSuper = true)
    <#else>
@EqualsAndHashCode(callSuper = false)
    </#if>
    <#if chainModel>
@Accessors(chain = true)
    </#if>
</#if>
<#if table.convert>
@TableName("${table.name}")
</#if>
<#if swagger2>
@ApiModel(value="${entity}对象", description="${table.comment!}")
</#if>
<#if superEntityClass??>
public class ${entity} extends ${superEntityClass}<#if activeRecord><${entity}></#if> {
<#elseif activeRecord>
public class ${entity} extends Model<${entity}> {
<#else>
public class ${entity} implements Serializable {
</#if>

<#if entitySerialVersionUID>
    private static final long serialVersionUID = 1L;
</#if>
<#-- ----------  BEGIN 字段循环遍历  ---------->
<#list table.fields as field>
    <#if field.keyFlag>
        <#assign keyPropertyName="${field.propertyName}"/>
    </#if>

    <#if field.comment!?length gt 0>
        <#if swagger2>
    @ApiModelProperty(value = "${field.comment}")
        <#else>
    /**
     * ${field.comment}
     */
        </#if>
    </#if>
    <#if field.keyFlag>
        <#-- 主键 -->
        <#if field.keyIdentityFlag>
    @TableId(value = "${field.annotationColumnName}", type = IdType.AUTO)
        <#elseif idType??>
    @TableId(value = "${field.annotationColumnName}", type = IdType.${idType})
        <#elseif field.convert>
    @TableId("${field.annotationColumnName}")
        </#if>
        <#-- 普通字段 -->
    <#elseif field.fill??>
    <#-- -----   存在字段填充设置   ----->
        <#if field.convert>
    @TableField(value = "${field.annotationColumnName}", fill = FieldFill.${field.fill})
        <#else>
    @TableField(fill = FieldFill.${field.fill})
        </#if>
    <#elseif field.convert>
    @TableField("${field.annotationColumnName}")
    </#if>
    <#-- 乐观锁注解 -->
    <#if (versionFieldName!"") == field.name>
    @Version
    </#if>
    <#-- 逻辑删除注解 -->
    <#if (logicDeleteFieldName!"") == field.name>
    @TableLogic
    </#if>
    private ${field.propertyType} ${field.propertyName};
</#list>
<#------------  END 字段循环遍历  ---------->

<#if !entityLombokModel>
    <#list table.fields as field>
        <#if field.propertyType == "boolean">
            <#assign getprefix="is"/>
        <#else>
            <#assign getprefix="get"/>
        </#if>
    public ${field.propertyType} ${getprefix}${field.capitalName}() {
        return ${field.propertyName};
    }

    <#if chainModel>
    public ${entity} set${field.capitalName}(${field.propertyType} ${field.propertyName}) {
    <#else>
    public void set${field.capitalName}(${field.propertyType} ${field.propertyName}) {
    </#if>
        this.${field.propertyName} = ${field.propertyName};
        <#if chainModel>
        return this;
        </#if>
    }
    </#list>
</#if>

<#if entityColumnConstant>
    <#list table.fields as field>
    public static final String ${field.name?upper_case} = "${field.name}";

    </#list>
</#if>
<#if activeRecord>
    @Override
    protected Serializable pkVal() {
    <#if keyPropertyName??>
        return this.${keyPropertyName};
    <#else>
        return null;
    </#if>
    }

</#if>
<#if !entityLombokModel>
    @Override
    public String toString() {
        return "${entity}{" +
    <#list table.fields as field>
        <#if field_index==0>
            "${field.propertyName}=" + ${field.propertyName} +
        <#else>
            ", ${field.propertyName}=" + ${field.propertyName} +
        </#if>
    </#list>
        "}";
    }
</#if>
}

service.java.ftl

text
package ${package.Service};

import ${package.Entity}.${entity};
import ${superServiceClassPackage};

/**
* <p>
* ${table.comment!} 服务类
* </p>
*
* @author ${author}
* @since ${date}
*/
<#if kotlin>
interface ${table.serviceName} : ${superServiceClass}<${entity}>
<#else>
public interface ${table.serviceName} extends ${superServiceClass}<${entity}> {

}
</#if>

serviceImpl.java.ftl

text
package ${package.ServiceImpl};

import ${package.Entity}.${entity};
import ${package.Mapper}.${table.mapperName};
import ${package.Service}.${table.serviceName};
import ${superServiceImplClassPackage};
import org.springframework.stereotype.Service;

/**
 * <p>
 * ${table.comment!} 服务实现类
 * </p>
 *
 * @author ${author}
 * @since ${date}
 */
@Service
<#if kotlin>
open class ${table.serviceImplName} : ${superServiceImplClass}<${table.mapperName}, ${entity}>(), ${table.serviceName} {

}
<#else>
public class ${table.serviceImplName} extends ${superServiceImplClass}<${table.mapperName}, ${entity}> implements ${table.serviceName} {

}
</#if>

mapper.java.ftl

text
package ${package.Mapper};

import ${package.Entity}.${entity};
import ${superMapperClassPackage};

/**
 * <p>
 * ${table.comment!} Mapper 接口
 * </p>
 *
 * @author ${author}
 * @since ${date}
 */
<#if kotlin>
interface ${table.mapperName} : ${superMapperClass}<${entity}>
<#else>
public interface ${table.mapperName} extends ${superMapperClass}<${entity}> {

}
</#if>

mapper.xml.ftl

text
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="${package.Mapper}.${table.mapperName}">

<#if enableCache>
    <!-- 开启二级缓存 -->
    <cache type="org.mybatis.caches.ehcache.LoggingEhcache"/>

</#if>
<#if baseResultMap>
    <!-- 通用查询映射结果 -->
    <resultMap id="BaseResultMap" type="${package.Entity}.${entity}">
<#list table.fields as field>
<#if field.keyFlag><#--生成主键排在第一位-->
        <id column="${field.name}" property="${field.propertyName}" />
</#if>
</#list>
<#list table.commonFields as field><#--生成公共字段 -->
        <result column="${field.name}" property="${field.propertyName}" />
</#list>
<#list table.fields as field>
<#if !field.keyFlag><#--生成普通字段 -->
        <result column="${field.name}" property="${field.propertyName}" />
</#if>
</#list>
    </resultMap>

</#if>
<#if baseColumnList>
    <!-- 通用查询结果列 -->
    <sql id="Base_Column_List">
<#list table.commonFields as field>
        ${field.columnName},
</#list>
        ${table.fieldNames}
    </sql>

</#if>
</mapper>

旧版生成器原理 ​

旧版生成器同样是读取表结构，再套用模板输出代码。它的流程和新版类似，只是配置 API、模板引擎和扩展方式不同。

mermaid
flowchart TD
    A["读取表结构"] --> B["生成 TableInfo 元数据"]
    B --> C["Velocity / Freemarker 模板"]
    C --> D["输出 Java / XML"]
    D --> E["人工调整"]

为什么不建议无脑使用旧版生成器 ​

旧版配置更分散，模板定制和新版 API 差异较大。新项目优先使用新版生成器；维护老项目时，也要注意生成代码可能覆盖手写内容。

风险 ​

  1. 生成代码覆盖已有代码。
  2. Entity 直接作为接口返回值。
  3. Service 只有空壳，没有事务和业务规则。
  4. Mapper XML 只适合基础 CRUD，复杂 SQL 仍要手写。