SpringBoot中幾種好用的程式碼生成器(基於Mybatis-plus生成entity、mapper、xml等)

sum墨發表於2024-04-28
Spring BootMyBatisAPPXML

前言

熟悉Spring框架的同學一定都知道MVC開發模式吧，控制器（Controller）、業務類（Service）、持久層（Repository）、資料庫對映（Mapper）、各種DO類構成了我們服務端的程式碼。初學的時候，覺得新鮮手寫這些東西不覺得有啥，但是寫久了就會覺得很煩。好不容易在資料庫中寫完了一遍欄位，在Java程式碼又要寫一遍，不僅很枯燥，關鍵是還容易寫錯！！！

欄位名稱寫錯的痛，只有踩過這坑的人才能體會... ...

所以，如果有一個工具可以在我們建立完資料庫表之後自動幫助我們生成各種類就好了。

這種工具不僅有，而且有很多，首先推薦一個最最簡單的：

線上版Java程式碼生成器

如果有用過bejson線上工具的小夥伴，應該很熟悉，不過這個工具有個缺點：
開發者需要自己手動建立程式碼目錄和程式碼檔案，然後一個一個將程式碼複製到檔案中

所以為了讓大家更省事一些，下面推薦的2種方法不僅可以生成程式碼，還可以直接建立好資料夾、程式碼類。這2種方法的效果差不多，自己看情況選用吧。

第一種：mybatis-plus-generator配合freemaker引擎

嘗試一下🍓

SpringBoot專案pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>SpringBoot-CodeGenerator</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>SpringBoot-CodeGenerator</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- 程式碼生成器 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>3.2.0</version>
        </dependency>
        <!-- freemaker引擎 -->
        <dependency>
            <groupId>org.freemarker</groupId>
            <artifactId>freemarker</artifactId>
            <version>2.3.29</version>
        </dependency>
        <!-- lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!-- mysql -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    </dependencies>

</project>

resources目錄

controller.java.ftl

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>

/**
 * @author ${author}
 */
<#if restControllerStyle>
@RestController
<#else>
@Controller
</#if>
@RequestMapping("<#if package.ModuleName??>/${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

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>

/**
* ${table.comment!}
*
* @author ${author}
*/
<#if entityLombokModel>
    @Data
    <#if superEntityClass??>
        @EqualsAndHashCode(callSuper = true)
    <#else>
        @EqualsAndHashCode(callSuper = false)
    </#if>
    @Accessors(chain = true)
</#if>
<#if table.convert>
    @TableName("${table.name}")
</#if>
<#if swagger2>
    @ApiModel(value="${entity}物件", description="${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 欄位迴圈遍歷  ---------->
<#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>
            /**
            * ${field.comment}
            */
        </#if>
    </#if>
    <#if field.keyFlag>
    <#-- 主鍵 -->
        <#if field.keyIdentityFlag>
            @TableId(value = "${field.name}", type = IdType.AUTO)
        <#elseif idType??>
            @TableId(value = "${field.name}", type = IdType.${idType})
        <#elseif field.convert>
            @TableId("${field.name}")
        </#if>
    <#-- 普通欄位 -->
    <#elseif field.fill??>
    <#-- -----   存在欄位填充設定   ----->
        <#if field.convert>
            @TableField(value = "${field.name}", fill = FieldFill.${field.fill})
        <#else>
            @TableField(fill = FieldFill.${field.fill})
        </#if>
    <#elseif field.convert>
        @TableField("${field.name}")
    </#if>
<#-- 樂觀鎖註解 -->
    <#if (versionFieldName!"") == field.name>
        @Version
    </#if>
<#-- 邏輯刪除註解 -->
    <#if (logicDeleteFieldName!"") == field.name>
        @TableLogic
    </#if>
    private ${field.propertyType} ${field.propertyName};
</#list>
<#------------  END 欄位迴圈遍歷  ---------->

<#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>
}

mapper.java.ftl

package ${package.Mapper};

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

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

}
</#if>

mapper.xml.ftl

<?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>
        <!-- 開啟二級快取 -->
        <cache type="org.mybatis.caches.ehcache.LoggingEhcache"/>

    </#if>
    <#if baseResultMap>
        <!-- 通用查詢對映結果 -->
        <resultMap id="BaseResultMap" type="${package.Entity}.${entity}">
            <#list table.fields as field>
                <#if field.keyFlag><#--生成主鍵排在第一位-->
                    <id column="${field.name}" property="${field.propertyName}" />
                </#if>
            </#list>
            <#list table.commonFields as field><#--生成公共欄位 -->
                <result column="${field.name}" property="${field.propertyName}" />
            </#list>
            <#list table.fields as field>
                <#if !field.keyFlag><#--生成普通欄位 -->
                    <result column="${field.name}" property="${field.propertyName}" />
                </#if>
            </#list>
        </resultMap>

    </#if>
    <#if baseColumnList>
        <!-- 通用查詢結果列 -->
        <sql id="Base_Column_List">
            <#list table.commonFields as field>
                ${field.name},
            </#list>
            ${table.fieldNames}
        </sql>

    </#if>
</mapper>

service.java.ftl

package ${package.Service};

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

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

}
</#if>

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;

/**
 * @author ${author}
 */
@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>

上面這些檔案直接建立在resources/generator1/templates的目錄下，把內容複製進去就行了。這些檔案就是你程式碼生成的格式模板，當然自己也可以修改。

生成程式碼

package com.example.springbootcodegenerator.util;

import com.baomidou.mybatisplus.core.exceptions.MybatisPlusException;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.config.*;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;

import java.util.Scanner;

/**
 * mybatis plus 提供的程式碼生成器
 * 可以快速生成 Entity、Mapper、Mapper XML、Service、Controller 等各個模組的程式碼
 *
 * @link https://mp.baomidou.com/guide/generator.html
 */
public class CodeGenerator {

    // 資料庫 URL
    private static final String URL = "jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC";
    // 資料庫驅動
    private static final String DRIVER_NAME = "com.mysql.cj.jdbc.Driver";
    // 資料庫使用者名稱
    private static final String USERNAME = "root";
    // 資料庫密碼
    private static final String PASSWORD = "123456";
    // @author 值
    private static final String AUTHOR = "sun墨";
    // 包的基礎路徑
    private static final String BASE_PACKAGE_URL = "com.example.springbootcodegenerator";
    // xml檔案路徑
    private static final String XML_PACKAGE_URL = "/src/main/resources/mapper/";
    // xml 檔案模板
    private static final String XML_MAPPER_TEMPLATE_PATH = "generator1/templates/mapper.xml";
    // mapper 檔案模板
    private static final String MAPPER_TEMPLATE_PATH = "generator1/templates/mapper.java";
    // entity 檔案模板
    private static final String ENTITY_TEMPLATE_PATH = "generator1/templates/entity.java";
    // service 檔案模板
    private static final String SERVICE_TEMPLATE_PATH = "generator1/templates/service.java";
    // serviceImpl 檔案模板
    private static final String SERVICE_IMPL_TEMPLATE_PATH = "generator1/templates/serviceImpl.java";
    // controller 檔案模板
    private static final String CONTROLLER_TEMPLATE_PATH = "generator1/templates/controller.java";

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

        // 全域性配置
        GlobalConfig globalConfig = new GlobalConfig();
        String projectPath = System.getProperty("user.dir");
        globalConfig.setOutputDir(projectPath + "/src/main/java");
        globalConfig.setAuthor(AUTHOR);
        globalConfig.setOpen(false);
        globalConfig.setFileOverride(false);
        generator.setGlobalConfig(globalConfig);

        // 資料來源配置
        DataSourceConfig dataSourceConfig = new DataSourceConfig();
        dataSourceConfig.setUrl(URL);
        dataSourceConfig.setDriverName(DRIVER_NAME);
        dataSourceConfig.setUsername(USERNAME);
        dataSourceConfig.setPassword(PASSWORD);
        generator.setDataSource(dataSourceConfig);

        // 包配置
        PackageConfig packageConfig = new PackageConfig();
        packageConfig.setModuleName("gen");
        packageConfig.setParent(BASE_PACKAGE_URL);
        generator.setPackageInfo(packageConfig);

        // 配置自定義程式碼模板
        TemplateConfig templateConfig = new TemplateConfig();
        templateConfig.setXml(XML_MAPPER_TEMPLATE_PATH);
        templateConfig.setMapper(MAPPER_TEMPLATE_PATH);
        templateConfig.setEntity(ENTITY_TEMPLATE_PATH);
        templateConfig.setService(SERVICE_TEMPLATE_PATH);
        templateConfig.setServiceImpl(SERVICE_IMPL_TEMPLATE_PATH);
        templateConfig.setController(CONTROLLER_TEMPLATE_PATH);
        generator.setTemplate(templateConfig);

        // 策略配置
        StrategyConfig strategy = new StrategyConfig();
        strategy.setNaming(NamingStrategy.underline_to_camel);
        strategy.setColumnNaming(NamingStrategy.underline_to_camel);
        strategy.setEntityLombokModel(true);
        strategy.setRestControllerStyle(true);
        strategy.setInclude(scanner("表名"));
        strategy.setSuperEntityColumns("id");
        strategy.setControllerMappingHyphenStyle(true);
        strategy.setTablePrefix(packageConfig.getModuleName() + "_");
        generator.setStrategy(strategy);
        generator.setTemplateEngine(new FreemarkerTemplateEngine());
        generator.execute();
    }

    private static String scanner(String tip) {
        Scanner scanner = new Scanner(System.in);
        System.out.println(("請輸入" + tip + "："));
        if (scanner.hasNext()) {
            String ipt = scanner.next();
            if (null != ipt && !"".equals(ipt)) {
                return ipt;
            }
        }
        throw new MybatisPlusException("請輸入正確的" + tip + "！");
    }
}

效果展示

執行這個類之後，輸入表名

程式碼目錄如下：

第二種：tk.mybatis配合maven外掛

嘗試一下🍓

SpringBoot專案pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>SpringBoot-CodeGenerator</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>SpringBoot-CodeGenerator</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- 程式碼生成器 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>3.2.0</version>
        </dependency>
        <!-- mybatis-plus -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.2.0</version>
        </dependency>
        <dependency>
            <groupId>javax.persistence</groupId>
            <artifactId>javax.persistence-api</artifactId>
        </dependency>
        <!-- lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!-- mysql -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <version>1.3.6</version>
                <configuration>
                    <configurationFile>${basedir}/src/main/resources/generator2/generatorConfiguration.xml
                    </configurationFile>
                    <overwrite>true</overwrite>
                    <verbose>true</verbose>
                </configuration>
                <dependencies>
                    <dependency>
                        <groupId>tk.mybatis</groupId>
                        <artifactId>mapper</artifactId>
                        <version>4.1.2</version>
                    </dependency>
                </dependencies>
            </plugin>
        </plugins>
    </build>
</project>

resources目錄

config.properties

## 驅動
jdbc.url=jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&useSSL=false
## 登入名
jdbc.user=root
## 登入密碼
jdbc.password=123456
## 表名
table.name=t_test
## DO
entity.name=TTestDO
## Mapper
mapper.name=TTestMapper

generatorConfiguration.xml

<!DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">

<generatorConfiguration>
    <properties resource="generator2/config.properties"/>

    <classPathEntry location="/Users/wzhi/Desktop/tools/mysql-connector-java-8.0.11.jar"/>
    <context id="Mysql" targetRuntime="MyBatis3Simple" defaultModelType="flat">
        <property name="beginningDelimiter" value="`"/>
        <property name="endingDelimiter" value="`"/>

        <plugin type="tk.mybatis.mapper.generator.MapperPlugin">
            <property name="mappers" value="com.baomidou.mybatisplus.core.mapper.BaseMapper"/>
            <!-- 外掛預設的通用mapper <property name="mappers" itemValue="tk.mybatis.mapper.common.Mapper"/>-->
            <property name="caseSensitive" value="true"/>
            <property name="lombok" value="Getter,Setter,Builder,NoArgsConstructor,AllArgsConstructor"/>
        </plugin>

        <!-- 載入驅動 -->
        <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"
                        connectionURL="${jdbc.url}"
                        userId="${jdbc.daUser}" password="${jdbc.password}"/>


        <javaModelGenerator targetPackage="com.example.springbootcodegenerator.entity"
                            targetProject="src/main/java"/>

        <sqlMapGenerator targetPackage="mybatis/mapper"
                         targetProject="src/main/resources/">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>

        <javaClientGenerator targetPackage="com.example.springbootcodegenerator.mapper"
                             targetProject="src/main/java"
                             type="XMLMAPPER">
        </javaClientGenerator>

        <table tableName="${table.name}" domainObjectName="${entity.name}"
               mapperName="${mapper.name}">
            <generatedKey column="id" sqlStatement="Mysql" identity="true"/>
        </table>

    </context>
</generatorConfiguration>

上面兩個檔案配置好之後，如果使用的是idea，且裝有maven外掛，在maven 的Plugins中會有一個mybatis-generator選項，點選mybatis-generator :generate即可執行

沒有這個外掛也不要緊，執行下面這個命令也可以

mvn mybatis-generator:generate

效果展示

總結一下

總體來說，這兩種方式的效果都是差不多的。第一種方式可以自己建立任意檔案，第二種方式專注於配置。個人喜歡第二種方式，不想寫程式碼而已🤤

問題總結

有些同學在使用的時候遇到一些問題，有的是隻建立了資料夾，有的是生成的entity不對，如下圖：

問題1、生成的是空目錄

有兩種可能，第一種是你們的配置不對，可以詳細對照一下我的配置；第二種就是輸出路徑不對，生成的檔案沒法輸出。

問題2、第一個方法的模版有問題

我看了下entity.java.ftl的內容確實不對，估計是當時複製錯了，已改正，謝謝提醒。

文末小彩蛋，自己花一個星期做的小網站，放出來給大家看看，網址如下：http://47.120.49.119:8080

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