mybatis-plus 高效代码生成工具

我们在使用spring boot开发的时候，数据来源大多来自MySQL数据库，当我们要去操作数据库的时候，需要编写很多繁琐相同的配置，为了提高开发效率，我们可以借助代码生成工具将配置代码生成好然后只需要在里面填充相应的业务代码即可，接下来我们正式开始。

1. 添加Maven依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    <version>2.1.2.RELEASE</version>
</dependency>
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.0.1</version>
</dependency>
<dependency>
    <groupId>io.swagger</groupId>
    <artifactId>swagger-models</artifactId>
    <version>1.5.22</version>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.8</version>
</dependency>

2. 添加配置文件模板

在项目资源目录resources下创建templates目录，templates目录下包含controller.java.ftl, entity.java.ftl, mapper.java.ftl, service.java.ftl, serviceImpl.java.ftl文件，具体内容如下：

• templates/controller.java.ftl

package ${package.Controller};

import io.swagger.annotations.Api;
import lombok.extern.slf4j.Slf4j;
import java.util.Map;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import ${package.Service}.${table.serviceName};


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

<#if restControllerStyle>
@RestController
<#else>
@Controller
</#if>
@Api(value = "/${package.ModuleName}", tags = "自行添加描述")
@Slf4j
@RequestMapping(value = "/${package.ModuleName}")
<#if kotlin>
class ${table.controllerName}<#if superControllerClass??> : ${superControllerClass}()</#if>
<#else>
<#if superControllerClass??>
public class ${table.controllerName} extends ${superControllerClass} {
<#else>
public class ${table.controllerName} {

</#if>
    @Autowired
    private ${table.serviceName} ${cfg.entityName};

    /**
     * 示例
     */
    @GetMapping("/list")
    public void list(@RequestParam Map<String, Object> params){
        return ;
    }
}
</#if>

• templates/entity.java.ftl

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;
import lombok.experimental.Accessors;
</#if>

<#if entityLombokModel>
@Data
    <#if superEntityClass??>
@EqualsAndHashCode(callSuper = true)
    <#else>
@EqualsAndHashCode(callSuper = false)
    </#if>
@Accessors(chain = true)
</#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>

    private static final long serialVersionUID = 1L;
<#-- ----------  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.name}", type = IdType.AUTO)
        <#elseif idType??>
    @TableId(value = "${field.name}", type = IdType.${idType})
        <#elseif field.convert>
    @TableId("${field.name}")
        </#if>
    <#-- 普通字段 -->
    <#elseif field.fill??>
    <#-- -----   存在字段填充设置   ----->
        <#if field.convert>
    @TableField(value = "${field.name}", fill = FieldFill.${field.fill})
        <#else>
    @TableField(fill = FieldFill.${field.fill})
        </#if>
    <#elseif field.convert>
    @TableField("${field.name}")
    </#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 entityBuilderModel>
    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 entityBuilderModel>
        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>
}

• templates/mapper.java.ftl

package ${package.Mapper};

import ${package.Entity}.${entity};
import ${superMapperClassPackage};
import org.apache.ibatis.annotations.Mapper;

<#if kotlin>
interface ${table.mapperName} : ${superMapperClass}<${entity}>
<#else>
@Mapper
public interface ${table.mapperName} extends ${superMapperClass}<${entity}> {

}
</#if>

• templates/service.java.ftl

package ${package.Service};

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

<#if kotlin>
interface ${table.serviceName} : ${superServiceClass}<${entity}>
<#else>
public interface ${table.serviceName} extends ${superServiceClass}<${entity}> {

}
</#if>

• templates/serviceImpl.java.ftl

package ${package.ServiceImpl};

import ${package.Entity}.${entity};
import ${package.Mapper}.${table.mapperName};
import ${package.Service}.${table.serviceName};
import ${superServiceImplClassPackage};
import org.springframework.stereotype.Service;
import lombok.extern.slf4j.Slf4j;
import java.util.Map;

@Service
@Slf4j
<#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>

3. 代码生成工具类

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.*;
import com.baomidou.mybatisplus.generator.config.po.TableInfo;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;

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

public class MybatisGenerator {

    interface GeneratorConfiguration {
        /*-----------------------频繁修改项--------------------------*/
        //模块名称,也可以理解为微服务的服务名称
        String module_name = "people";
        //父包名
        String module_parent = "com.test";
        //表名称,如果表名称带"t_"则默认会裁去
        String[] table_names = new String[]{"t_people"};
        //数据库url
        String db_url = "jdbc:mysql://192.168.1.100:3306/test?useUnicode=true&useSSL=false&characterEncoding=utf8";
        //数据库账户名
        String db_username = "root";
        //数据库密码
        String db_password = "12345678";
        /*-----------------------不频繁修改项--------------------------*/
        //数据库驱动
        String db_driver = "com.mysql.jdbc.Driver";
        //工程目录
        String projectPath = System.getProperty("user.dir");
    }

    public static void main(String[] args) {
        MybatisGenerator mybatisGenerator = new MybatisGenerator();
        mybatisGenerator.execute();
    }

    private void execute() {
        getGenerator().execute();
    }

    private AutoGenerator getGenerator() {
        AutoGenerator mpg = new AutoGenerator();
        mpg.setGlobalConfig(getGlobalConfig());
        mpg.setDataSource(getDataSourceConfig());
        mpg.setPackageInfo(getPackageInfo());
        mpg.setCfg(getInjectionConfig());
        mpg.setTemplate(getTemplateConfig());
        mpg.setStrategy(getStrategyConfig());
        mpg.setTemplateEngine(new FreemarkerTemplateEngine());
        return mpg;
    }

    private StrategyConfig getStrategyConfig() {
        // 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");
        strategy.setEntityLombokModel(true);
        strategy.setRestControllerStyle(true);
        // 公共父类
//        strategy.setSuperControllerClass("com.baomidou.ant.common.BaseController");
        // 写于父类中的公共字段
//        strategy.setSuperEntityColumns("id");
        strategy.setInclude(GeneratorConfiguration.table_names);
        strategy.setControllerMappingHyphenStyle(true);
        strategy.setTablePrefix("t_");
        return strategy;
    }

    private TemplateConfig getTemplateConfig() {
        TemplateConfig tc = new TemplateConfig();
        // 配置自定义输出模板
        //指定自定义模板路径，注意不要带上.ftl/.vm, 会根据使用的模板引擎自动识别
        tc.setEntity("/templates/entity.java");
        tc.setXml(null);
        tc.setMapper("/templates/mapper.java");
        tc.setService("/templates/service.java");
        tc.setServiceImpl("/templates/serviceImpl.java");
        tc.setController("/templates/controller.java");
        return tc;
    }


    private InjectionConfig getInjectionConfig() {
        InjectionConfig cfg = new InjectionConfig() {
            @Override
            public void initMap() {
                HashMap<String, Object> map = new HashMap<String, Object>();
                map.put("basePath", GeneratorConfiguration.module_parent);
                map.put("urlPrefix", "/api/vi");
                String entityName = this.getConfig().getTableInfoList().get(0).getServiceName();
                entityName = entityName.substring(0, 1).toLowerCase() + entityName.substring(1);
                map.put("entityName", entityName);
                this.setMap(map);
            }
        };
        // 如果模板引擎是 freemarker
        String templatePath = "/templates/mapper.xml.ftl";
        // 如果模板引擎是 velocity
        // String templatePath = "/templates/mapper.xml.vm";

        // 自定义输出配置
        List<FileOutConfig> focList = new ArrayList<FileOutConfig>();
        // 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 GeneratorConfiguration.projectPath
                        + "/src/main/resources/mapper/"
                        + GeneratorConfiguration.module_name
                        + "/" + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;
            }
        });
        cfg.setFileOutConfigList(focList);
        return cfg;
    }

    // 包配置
    private PackageConfig getPackageInfo() {
        PackageConfig pc = new PackageConfig();
        pc.setModuleName(GeneratorConfiguration.module_name);
        pc.setParent(GeneratorConfiguration.module_parent);
        return pc;
    }

    // 数据源配置
    private DataSourceConfig getDataSourceConfig() {
        DataSourceConfig dsc = new DataSourceConfig();
        dsc.setUrl(GeneratorConfiguration.db_url);
        // dsc.setSchemaName("public");
        dsc.setDriverName(GeneratorConfiguration.db_driver);
        dsc.setUsername(GeneratorConfiguration.db_username);
        dsc.setPassword(GeneratorConfiguration.db_password);
        return dsc;
    }

    // 全局配置
    private GlobalConfig getGlobalConfig() {
        GlobalConfig gc = new GlobalConfig();
        gc.setOutputDir(GeneratorConfiguration.projectPath + "/src/main/java");
        gc.setBaseResultMap(true);
        gc.setBaseColumnList(true);
        gc.setOpen(false);
        gc.setSwagger2(true);
        gc.setControllerName("%sController");
        gc.setServiceName("%sService");
        gc.setIdType(IdType.ID_WORKER_STR);
        return gc;
    }
}

最后运行MybatisGenerator.java代码即可生成相应代码。