使用MybatisPlus Generator生成优雅的代码、自定义的代码

       撸代码的最高境界就是让代码帮你撸代码。目前mybatis相关的代码生成器都挺友好的，最后生成最简洁清爽易读，还得看mybatisplus-generator。使用mybatisplus-generator不一定需要是mybatisplus作为持久层框架，也可以生成通用mapper+mybatis的代码。代码模板都可以自定义，而且还支持多种代码模板。以下就是我用其中一种模板封装的代码生成器，供大家参考。

1.加入标准的maven依赖

  mysql
  mysql-connector-java
   8.0 . 19 


  com.oracle.database.jdbc
  ojdbc8
   19.13 . 0.0 



  org.projectlombok
  lombok
   1.18 . 20 
  provided



  org.springframework.boot
  spring-boot-starter-web



  io.springfox
  springfox-swagger2
   2.4 . 0 


  io.springfox
  springfox-swagger-ui
   2.4 . 0 


  com.github.xiaoymin
  swagger-bootstrap-ui
   1.9 . 6 



  tk.mybatis
  mapper-spring-boot-starter
   2.1 . 5 



  com.alibaba
  fastjson
   1.2 . 70 



  com.baomidou
  mybatis-plus-generator
   3.4 . 1 


  org.apache.velocity
  velocity-engine-core
   2.3 
    

　　

2.编写标准的核心代码

package org.example.core;

import com.baomidou.mybatisplus.annotation.IdType;
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.VelocityTemplateEngine;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import org.apache.commons.lang3.StringUtils;
import org.example.entity.dto.CodeGeneratorParamDTO;
import org.springframework.stereotype.Service;

/**
 * 代码生成服务类
 **/
@Service
public class CodeGenerator {

  public void execute(CodeGeneratorParamDTO codeGeneratorParamDTO) {
    // 代码生成器
    AutoGenerator mpg =   new AutoGenerator();
    // 全局配置
    GlobalConfig globalConfig =   this .configGlobal(codeGeneratorParamDTO);
    mpg.setGlobalConfig(globalConfig);

    // 配置数据源
    DataSourceConfig dataSourceConfig =   this .configDataSource(codeGeneratorParamDTO);
    mpg.setDataSource(dataSourceConfig);

    // 配置包规则
    PackageConfig packageConfig =   this .configPackage(codeGeneratorParamDTO);
    mpg.setPackageInfo(packageConfig);

    // 自定义配置
    InjectionConfig injectionConfig =   this .configInjection(codeGeneratorParamDTO, packageConfig);
    mpg.setCfg(injectionConfig);

    // 配置要生成的模板
    TemplateConfig templateConfig =   this .configTemplate(codeGeneratorParamDTO);
    mpg.setTemplate(templateConfig);
    // 配置生成策略
    StrategyConfig strategyConfig =   this .configStrategy(codeGeneratorParamDTO);
    mpg.setStrategy(strategyConfig);

    // 设置模板引擎
    mpg.setTemplateEngine(  new VelocityTemplateEngine());
    mpg.execute();
  }

  private GlobalConfig configGlobal(CodeGeneratorParamDTO codeGeneratorParamDTO) {
    String projectPath = codeGeneratorParamDTO.getProjectPath();
    if (!projectPath.endsWith(  "\\" ) && !projectPath.endsWith(  "/" )){
      projectPath = projectPath +  "\\" ;
    }
    String javaCodeOutputPath = projectPath +   "src\\main\\java" ;
    GlobalConfig globalConfig =   new GlobalConfig();
    globalConfig.setOutputDir(javaCodeOutputPath)
        .setAuthor(codeGeneratorParamDTO.getAuthorName())
        .setIdType(IdType.AUTO)
        .setBaseColumnList(  true )
        .setBaseResultMap(  true )
        .setOpen(  false )
        .setFileOverride(codeGeneratorParamDTO.getIsOverride())
        .setServiceName(  "%sService" )
        .setMapperName(  "%sDao" );
    return globalConfig;
  }

  private DataSourceConfig configDataSource(CodeGeneratorParamDTO codeGeneratorParamDTO) {
    // 数据源配置
    DataSourceConfig dataSourceConfig =   new DataSourceConfig();
    dataSourceConfig.setUrl(codeGeneratorParamDTO.getDataSourceUrl());
    dataSourceConfig.setDriverName(codeGeneratorParamDTO.getDataSourceDriver());
    dataSourceConfig.setUsername(codeGeneratorParamDTO.getDataSourceUserName());
    dataSourceConfig.setPassword(codeGeneratorParamDTO.getDataSourcePassword());
    return dataSourceConfig;
  }

  private PackageConfig configPackage(CodeGeneratorParamDTO codeGeneratorParamDTO) {
    // 包配置
    PackageConfig packageConfig =   new PackageConfig();
    packageConfig.setParent(codeGeneratorParamDTO.getBasePackageName());
    packageConfig.setService(codeGeneratorParamDTO.getServicePackageName());
    packageConfig.setServiceImpl(packageConfig.getService() +   ".impl" );
    packageConfig.setMapper(codeGeneratorParamDTO.getDaoPackageName());
    packageConfig.setEntity(codeGeneratorParamDTO.getEntityPackageName());
    return packageConfig;

  }

  private InjectionConfig configInjection(CodeGeneratorParamDTO codeGeneratorParamDTO, PackageConfig packageConfig) {
    // 自定义配置
    InjectionConfig injectionConfig =   new InjectionConfig() {
      @Override
      public void initMap() {
        // to do nothing
      }
    };
    // 指定模板引擎是 velocity
    String templatePath =   "/templates/mapper.xml.vm" ;

    // 自定义输出配置
    List 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
        return codeGeneratorParamDTO.getProjectPath() +   "/" + StringUtils.join(codeGeneratorParamDTO.getMapperXmlPath(),packageConfig.getModuleName())
            +   "/" + tableInfo.getEntityName() +   "Mapper" + StringPool.DOT_XML;
      }
    });
    injectionConfig.setFileOutConfigList(focList);
    return injectionConfig;
  }

  private TemplateConfig configTemplate(CodeGeneratorParamDTO codeGeneratorParamDTO) {
    // 配置模板
    TemplateConfig templateConfig =   new TemplateConfig();
    // 配置自定义输出模板
    if (Objects.equals(codeGeneratorParamDTO.getIsNeedController(), Boolean.FALSE)){
      templateConfig.setController(  null );
    }
    if (Objects.equals(codeGeneratorParamDTO.getIsNeedMapper(), Boolean.FALSE)){
      templateConfig.setXml(  null );
    }
    if (Objects.equals(codeGeneratorParamDTO.getIsNeedDao(), Boolean.FALSE)){
      templateConfig.setMapper(  null );
    }
    if (Objects.equals(codeGeneratorParamDTO.getIsNeedEntity(), Boolean.FALSE)){
      templateConfig.setEntity(  null );
    }
    if (Objects.equals(codeGeneratorParamDTO.getIsNeedService(), Boolean.FALSE)){
      templateConfig.setService(  null );
      templateConfig.setServiceImpl(  null );
    }
    return templateConfig;
  }

  private StrategyConfig configStrategy(CodeGeneratorParamDTO codeGeneratorParamDTO) {
    StrategyConfig strategyConfig =   new StrategyConfig();
    strategyConfig.setNaming(NamingStrategy.underline_to_camel);
    strategyConfig.setColumnNaming(NamingStrategy.underline_to_camel);
    // 通用mapper作为父类则这里为：tk.mybatis.mapper.common.BaseMapper，如果是mybatisplus则改为com.baomidou.mybatisplus.core.mapper.BaseMapper
    strategyConfig.setSuperMapperClass(  "tk.mybatis.mapper.common.BaseMapper" );
    strategyConfig.setEntityLombokModel(  true );
    strategyConfig.setRestControllerStyle(  true );
    // 公共父类
    strategyConfig.setInclude(codeGeneratorParamDTO.getTableNames().split(  "," ));
    strategyConfig.setControllerMappingHyphenStyle(  true );
    strategyConfig.setTablePrefix(codeGeneratorParamDTO.getTablePrefix());
    strategyConfig.setEntityTableFieldAnnotationEnable(  false );
    strategyConfig.setEntitySerialVersionUID(  false );
    return strategyConfig;
  }

}

　　

3.传入标准的核心参数

package org.example.entity.dto;

import io.swagger.annotations.ApiModelProperty;
import java.io.Serializable;
import lombok.Data;

/**
 * 代码生成器的传参
 *
 **/
@Data
public class CodeGeneratorParamDTO   implements Serializable {

  @ApiModelProperty (value =   "项目所在目录：如：D:\\project\\demo" , required =   true , position =   1 )
  private String projectPath;

  @ApiModelProperty (value =   "生成代码后所在的基础包，如com.example" , required =   true , position =   2 )
  private String basePackageName;

  @ApiModelProperty (value =   "数据源连接的url" ,required =   true , position =   3 )
  private String dataSourceUrl;

  @ApiModelProperty (value =   "数据源连接的驱动，默认为com.mysql.cj.jdbc.Driver。只支持mysql与Oracle" , hidden =   true )
  private String dataSourceDriver =  "com.mysql.cj.jdbc.Driver" ;

  @ApiModelProperty (value =   "数据源-数据库的用户" , required =   true , position =   4 )
  private String dataSourceUserName;

  @ApiModelProperty (value =   "数据源-数据库的密码" , required =   true , position =   5 )
  private String dataSourcePassword;

  @ApiModelProperty (value =   "生成代码的表名，多个表名用英文的逗号隔开" , required =   true , position =   6 )
  private String tableNames;

  @ApiModelProperty (  "mapper.xml文件所在项目的相对目录，如：src/main/resources/mapper/，默认src/main/resources/mapper/" )
  private String mapperXmlPath =  "src/main/resources/mapper/" ;

  @ApiModelProperty (  "service所在的包名，如：service，默认service" )
  private String servicePackageName =  "service" ;

  @ApiModelProperty (  "dao所在的包名，如：dao，默认dao" )
  private String daoPackageName =  "dao" ;

  @ApiModelProperty (  "生成的实体所在的包名，如：entity.po，默认entity.po" )
  private String entityPackageName =  "entity.po" ;

  @ApiModelProperty (  "生成代码需要去掉的表的前缀" )
  private String tablePrefix;

  @ApiModelProperty (  "生成代码是否覆盖原有的类 false否 true是，默认true" )
  private Boolean isOverride =  true ;

  @ApiModelProperty (  "是否需要生成controller类 false否 true是，默认false" )
  private Boolean isNeedController =  false ;

  @ApiModelProperty (  "是否需要生成service类 false否 true是，默认false" )
  private Boolean isNeedService =  false ;

  @ApiModelProperty (  "是否需要生成dao类 false否 true是，默认true" )
  private Boolean isNeedDao =  true ;

  @ApiModelProperty (  "是否需要生成mapper.xml false否 true是，默认true" )
  private Boolean isNeedMapper =  true ;

  @ApiModelProperty (  "是否需要生成entity false否 true是，默认true" )
  private Boolean isNeedEntity =  true ;

  @ApiModelProperty (  "代码生成当前开发者名称" )
  private String authorName;
}

　　

4.输出标准的优雅代码

略