纯 Java 项目（非 SpringBoot）集成 Mybatis-Plus 和 Mybatis-Plus-Join

1、依赖

1.1、依赖版本

依赖	版本
Mysql-Connector-J	9.3.0
HikariCP	5.1.0
SnakeYaml	2.4
Lombok	1.18.38
Mybatis-Plus	3.5.9
Mybatis-Plus Generator	3.5.9
Mybatis-Plus-Join	1.4.13
Spring-Core	5.3.39

1.2、pom.xml

<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.wxhnyfy</groupId><artifactId>maven-mybatis-plus</artifactId><version>1.0</version><packaging>jar</packaging><name>maven-mybatis-plus</name><url>http://maven.apache.org</url><properties><java.version>11</java.version><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><junit.version>4.13.1</junit.version><mybatis-plus.version>3.5.9</mybatis-plus.version><mybatis-plus-join.version>1.4.13</mybatis-plus-join.version><org.apache.logging.log4j.version>2.23.1</org.apache.logging.log4j.version><slf4j-reload4j.version>2.0.12</slf4j-reload4j.version><mysql-connector-java.version>9.3.0</mysql-connector-java.version><hikaricp.version>5.1.0</hikaricp.version><freemarker.version>2.3.32</freemarker.version><fastjson2.version>2.0.51</fastjson2.version><vfs.version>3.3.2.Final</vfs.version><lombok.version>1.18.38</lombok.version><snakeyaml.version>2.4</snakeyaml.version><commons-io.version>2.19.0</commons-io.version><spring-core.version>5.3.39</spring-core.version></properties><dependencies><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-core</artifactId><version>${org.apache.logging.log4j.version}</version></dependency><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-api</artifactId><version>${org.apache.logging.log4j.version}</version></dependency><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-reload4j</artifactId><version>${slf4j-reload4j.version}</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>${junit.version}</version><scope>test</scope></dependency><dependency><groupId>org.freemarker</groupId><artifactId>freemarker</artifactId><version>${freemarker.version}</version></dependency><dependency><groupId>com.alibaba.fastjson2</groupId><artifactId>fastjson2</artifactId><version>${fastjson2.version}</version></dependency><dependency><groupId>org.jboss</groupId><artifactId>jboss-vfs</artifactId><version>${vfs.version}</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>${lombok.version}</version></dependency><dependency><groupId>org.yaml</groupId><artifactId>snakeyaml</artifactId><version>${snakeyaml.version}</version></dependency><dependency><groupId>commons-io</groupId><artifactId>commons-io</artifactId><version>${commons-io.version}</version></dependency><dependency><groupId>com.zaxxer</groupId><artifactId>HikariCP</artifactId><version>${hikaricp.version}</version><exclusions><exclusion><groupId>org.slf4j</groupId><artifactId>slf4j-api</artifactId></exclusion></exclusions></dependency><dependency><groupId>com.mysql</groupId><artifactId>mysql-connector-j</artifactId><version>${mysql-connector-java.version}</version></dependency><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus</artifactId><version>${mybatis-plus.version}</version></dependency><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-extension</artifactId><version>${mybatis-plus.version}</version></dependency><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-generator</artifactId><version>${mybatis-plus.version}</version></dependency><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-jsqlparser</artifactId><version>${mybatis-plus.version}</version></dependency><dependency><groupId>com.github.yulichang</groupId><artifactId>mybatis-plus-join</artifactId><version>${mybatis-plus-join.version}</version></dependency><!-- mybatis-plus-join反射需要用到 --><dependency><groupId>org.springframework</groupId><artifactId>spring-core</artifactId><version>${spring-core.version}</version></dependency></dependencies><build><resources><resource><directory>src/main/resources</directory><includes><include>**</include></includes></resource><!-- 扫描java目录下的xml文件 --><resource><directory>src/main/java</directory><includes><include>**/*.xml</include></includes></resource></resources><testResources><testResource><directory>src/main/resources</directory><includes><include>**</include></includes></testResource><testResource><directory>src/main/java</directory><includes><include>**/*.xml</include></includes></testResource></testResources><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><version>3.3</version><configuration><source>${java.version}</source><target>${java.version}</target><encoding>${project.build.sourceEncoding}</encoding></configuration></plugin></plugins></build>
</project>

2、代码

2.1、SqlSession 构造器

package com.wxhnyfy;import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONWriter;
import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.core.MybatisConfiguration;
import com.baomidou.mybatisplus.core.config.GlobalConfig;
import com.baomidou.mybatisplus.core.injector.DefaultSqlInjector;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.core.toolkit.GlobalConfigUtils;
import com.baomidou.mybatisplus.core.incrementer.DefaultIdentifierGenerator;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import com.github.yulichang.base.MPJBaseMapper;
import com.github.yulichang.injector.MPJSqlInjector;
import com.github.yulichang.interceptor.MPJInterceptor;
import com.zaxxer.hikari.HikariDataSource;
import org.apache.ibatis.builder.xml.XMLMapperBuilder;
import org.apache.ibatis.mapping.Environment;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.apache.ibatis.session.SqlSessionManager;
import org.apache.ibatis.transaction.jdbc.JdbcTransactionFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;import javax.sql.DataSource;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.JarURLConnection;
import java.net.URL;
import java.util.Enumeration;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;/*** 获取SqlSession** @author wxhnyfy*/
public class GetSqlSession {private static final Logger logger = LoggerFactory.getLogger(GetSqlSession.class);private static final ProjectConfiguration CONFIGURATION = ProjectConfiguration.getConfiguration();/*** SqlSession*/private static SqlSession sqlSession;/*** SqlSessionFactory*/private static SqlSessionFactory sqlSessionFactory;/*** SqlSessionManager*/private static SqlSessionManager sqlSessionManager;/*** 获取SqlSessionFactory*/private static void setMybatisPlusSqlSessionFactory() {SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();//这是mybatis-plus的配置对象，对mybatis的Configuration进行增强MybatisConfiguration configuration = new MybatisConfiguration();//构建mybatis-plus需要的globalconfigGlobalConfig globalConfig = new GlobalConfig();//必须初始化dbconfig，否则会报空指针globalConfig.setDbConfig(new GlobalConfig.DbConfig());//此参数会自动生成实现baseMapper的基础方法映射globalConfig.setSqlInjector(new DefaultSqlInjector());//设置id生成器globalConfig.setIdentifierGenerator(DefaultIdentifierGenerator.getInstance());//设置超类mapperglobalConfig.setSuperMapperClass(BaseMapper.class);//globalConfig必须在添加Mapper之前设置到全局变量，否则会读取不到SQL注入器GlobalConfigUtils.setGlobalConfig(configuration, globalConfig);//这是初始化配置，后面会添加这部分代码initConfiguration(configuration);//设置数据源Environment environment = new Environment("1", new JdbcTransactionFactory(), initDataSource());configuration.setEnvironment(environment);try {registryMapperXml(configuration, CONFIGURATION.getMybatisPlusConfiguration().getMapperConfiguration().getXmlPackage());} catch (IOException e) {throw new RuntimeException(e);}//构建sqlSessionFactorysqlSessionFactory = sqlSessionFactoryBuilder.build(configuration);}/*** 获取 MybatisPlus-Join SqlSessionFactory*/private static void setMybatisPlusJoinSqlSessionFactory() {SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();//这是mybatis-plus的配置对象，对mybatis的Configuration进行增强MybatisConfiguration configuration = new MybatisConfiguration();//添加拦截器 MPJInterceptorconfiguration.addInterceptor(new MPJInterceptor());//构建mybatis-plus需要的globalconfigGlobalConfig globalConfig = new GlobalConfig();//必须初始化dbconfig，否则会报空指针globalConfig.setDbConfig(new GlobalConfig.DbConfig());//此参数会自动生成实现baseMapper的基础方法映射globalConfig.setSqlInjector(new MPJSqlInjector());//设置id生成器globalConfig.setIdentifierGenerator(DefaultIdentifierGenerator.getInstance());//设置超类mapperglobalConfig.setSuperMapperClass(MPJBaseMapper.class);//globalConfig必须在添加Mapper之前设置到全局变量，否则会读取不到SQL注入器GlobalConfigUtils.setGlobalConfig(configuration, globalConfig);//这是初始化配置，后面会添加这部分代码initConfiguration(configuration);//设置数据源Environment environment = new Environment("1", new JdbcTransactionFactory(), initDataSource());configuration.setEnvironment(environment);try {registryMapperXml(configuration, CONFIGURATION.getMybatisPlusConfiguration().getMapperConfiguration().getXmlPackage());} catch (IOException e) {throw new RuntimeException(e);}logger.debug("已注册的方法：{}", JSON.toJSONString(configuration.getMappedStatementNames(), JSONWriter.Feature.WriteMapNullValue));//构建sqlSessionFactorysqlSessionFactory = sqlSessionFactoryBuilder.build(configuration);}/*** 获取SqlSession（线程不安全）** @return sqlSession*/public static SqlSession getMybatisPlusSqlSession() {if (sqlSession == null) {setMybatisPlusSqlSessionFactory();sqlSession = sqlSessionFactory.openSession(true);}return sqlSession;}/*** 获取线程安全的SqlSessionManager** @return sqlSessionManager*/public static SqlSessionManager safeMybatisPlusSqlSession() {if (sqlSessionManager == null) {setMybatisPlusSqlSessionFactory();sqlSessionManager = SqlSessionManager.newInstance(sqlSessionFactory);}return sqlSessionManager;}/*** 获取线程安全的SqlSessionManager** @return sqlSessionManager*/public static SqlSessionManager safeMybatisPlusJoinSqlSession() {if (sqlSessionManager == null) {setMybatisPlusJoinSqlSessionFactory();sqlSessionManager = SqlSessionManager.newInstance(sqlSessionFactory);}return sqlSessionManager;}/*** 清理SqlSession*/public static void cleanSqlSession() {if (sqlSession != null) {sqlSession.clearCache();}}/*** 清理sqlSessionManager*/public static void cleanSqlSessionManager() {if (sqlSessionManager != null) {sqlSessionManager.clearCache();}}/*** 初始化配置** @param configuration configuration*/private static void initConfiguration(MybatisConfiguration configuration) {//开启驼峰大小写转换configuration.setMapUnderscoreToCamelCase(CONFIGURATION.getMybatisPlusConfiguration().getMapperConfiguration().isMapUnderscoreToCamelCase());//配置添加数据自动返回数据主键configuration.setUseGeneratedKeys(CONFIGURATION.getMybatisPlusConfiguration().getMapperConfiguration().isUseGeneratedKeys());//这是初始化连接器，如mybatis-plus的分页插件configuration.addInterceptor(initInterceptor());//配置日志实现，如果需要打印结果集，则取消注释//configuration.setLogImpl(StdOutImpl.class);//扫描mapper接口所在包configuration.addMappers(CONFIGURATION.getMybatisPlusConfiguration().getMapperConfiguration().getMapperPackage());}/*** 初始化数据源** @return DataSource*/private static DataSource initDataSource() {HikariDataSource dataSource = new HikariDataSource();dataSource.setJdbcUrl(CONFIGURATION.getJdbc().getUrl());dataSource.setDriverClassName(CONFIGURATION.getJdbc().getDriverClassName());dataSource.setUsername(CONFIGURATION.getJdbc().getUsername());dataSource.setPassword(CONFIGURATION.getJdbc().getPassword());dataSource.setIdleTimeout(60000);dataSource.setAutoCommit(true);dataSource.setMaximumPoolSize(5);dataSource.setMinimumIdle(1);dataSource.setMaxLifetime(60000 * 10);dataSource.setConnectionTestQuery("SELECT 1");return dataSource;}/*** 初始化分页拦截器** @return Interceptor*/private static Interceptor initInterceptor() {//创建mybatis-plus插件对象MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();//构建分页插件PaginationInnerInterceptor paginationInnerInterceptor = new PaginationInnerInterceptor();paginationInnerInterceptor.setDbType(DbType.MYSQL);paginationInnerInterceptor.setOverflow(true);paginationInnerInterceptor.setMaxLimit(200L);interceptor.addInnerInterceptor(paginationInnerInterceptor);return interceptor;}/*** 解析mapper.xml文件** @param configuration MybatisConfiguration* @param classPath     包名* @throws IOException 异常*/private static void registryMapperXml(MybatisConfiguration configuration, String classPath) throws IOException {ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();Enumeration<URL> mapper = contextClassLoader.getResources(classPath);while (mapper.hasMoreElements()) {URL url = mapper.nextElement();if ("file".equals(url.getProtocol())) {String path = url.getPath();File file = new File(path);File[] files = file.listFiles();if (files != null) {for (File f : files) {FileInputStream in = new FileInputStream(f);XMLMapperBuilder xmlMapperBuilder = new XMLMapperBuilder(in, configuration, f.getPath(), configuration.getSqlFragments());xmlMapperBuilder.parse();in.close();}}} else {JarURLConnection urlConnection = (JarURLConnection) url.openConnection();JarFile jarFile = urlConnection.getJarFile();Enumeration<JarEntry> entries = jarFile.entries();while (entries.hasMoreElements()) {JarEntry jarEntry = entries.nextElement();if (jarEntry.getName().endsWith(".xml")) {InputStream in = jarFile.getInputStream(jarEntry);XMLMapperBuilder xmlMapperBuilder = new XMLMapperBuilder(in, configuration, jarEntry.getName(), configuration.getSqlFragments());xmlMapperBuilder.parse();in.close();}}}}}
}

2.2、MybatisPlus代码生成器

package com.wxhnyfy;import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONWriter;
import com.baomidou.mybatisplus.generator.FastAutoGenerator;
import com.baomidou.mybatisplus.generator.config.*;
import com.baomidou.mybatisplus.generator.config.builder.Entity;
import com.baomidou.mybatisplus.generator.config.builder.Mapper;
import com.baomidou.mybatisplus.generator.config.rules.DbColumnType;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;import java.io.File;
import java.sql.Types;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.function.Consumer;/*** MybatisPlus代码生成器** @author wxhnyfy* @package com.wxhnyfy* @project maven-mybatis-plus* @date 2025/6/7*/
public class MybatisPlusGenerator {private static final Logger logger = LoggerFactory.getLogger(MybatisPlusGenerator.class);private static final ProjectConfiguration CONFIGURATION = ProjectConfiguration.getConfiguration();/*** 输出目录*/private static String OUTPUT_DIR;/*** xml文件输出目录*/private static String XML_FILE_OUTPUT_DIR;private static void initPath() {// 获取项目根目录File file = new File("1.txt");String projectPath = file.getAbsolutePath().replace(file.getName(), "");String projectName = CONFIGURATION.getMybatisPlusConfiguration().getGenerator().getProjectName();if (null != projectName &&!projectName.isEmpty()) {if (!projectName.endsWith("\\")) {CONFIGURATION.getMybatisPlusConfiguration().getGenerator().setProjectName(projectName + "\\");}projectPath = file.getAbsolutePath().replace(file.getName(), "")+ CONFIGURATION.getMybatisPlusConfiguration().getGenerator().getProjectName();}logger.info(">>>> 项目根目录: {}", projectPath);OUTPUT_DIR = projectPath + CONFIGURATION.getMybatisPlusConfiguration().getGenerator().getCodeDir();XML_FILE_OUTPUT_DIR = projectPath + CONFIGURATION.getMybatisPlusConfiguration().getGenerator().getXmlDir();logger.info(">>>> java文件输出目录: {}", OUTPUT_DIR);logger.info(">>>> xml文件输出目录: {}", XML_FILE_OUTPUT_DIR);}/*** 获取策略配置** @param queryList           表名* @param isGenerateMpjMapper 是否生成mpj mapper* @return 策略配置*/private static Consumer<StrategyConfig.Builder> getStrategyConfigBuilder(List<String> queryList, boolean isGenerateMpjMapper) {return builder -> {boolean isGenerateMapperXml = CONFIGURATION.getMybatisPlusConfiguration().getGenerator().isGenerateMapperXml();boolean isUseDefaultFreemarkerTemplate = CONFIGURATION.getMybatisPlusConfiguration().getGenerator().isUseDefaultFreemarkerTemplate();boolean isEnableLombok = CONFIGURATION.getMybatisPlusConfiguration().getGenerator().isEnableLombok();builder.addInclude(queryList).controllerBuilder().disable().serviceBuilder().disableService().disableServiceImpl().disable();Mapper.Builder mapperBuilder = builder.mapperBuilder();Entity.Builder entityBuilder = builder.entityBuilder();if (isGenerateMapperXml) {if (isGenerateMpjMapper) {mapperBuilder.enableFileOverride().mapperTemplate("/templates/mapper-mpj.java");} else {mapperBuilder.enableFileOverride();}} else {if (isGenerateMpjMapper) {mapperBuilder.disableMapperXml().enableFileOverride().mapperTemplate("/templates/mapper-mpj.java");} else {mapperBuilder.disableMapperXml().enableFileOverride();}}if (isEnableLombok) {if (isUseDefaultFreemarkerTemplate) {entityBuilder.enableLombok().enableFileOverride();} else {entityBuilder.enableLombok().enableFileOverride().javaTemplate("/templates/entity.java");}} else {entityBuilder.enableFileOverride();}};}/*** 全局配置** @return 全局配置*/private static Consumer<GlobalConfig.Builder> getGlobalConfigBuilder() {return builder -> {// 设置作者builder.author(CONFIGURATION.getMybatisPlusConfiguration().getGenerator().getAuthor())// 生成后不打开目录.disableOpenDir()// 指定输出目录.outputDir(OUTPUT_DIR);};}/*** 数据源配置** @return 数据源配置*/private static Consumer<DataSourceConfig.Builder> getDataSourceConfigBuilder() {return builder ->builder.typeConvertHandler((globalConfig, typeRegistry, metaInfo) -> {int typeCode = metaInfo.getJdbcType().TYPE_CODE;if (typeCode == Types.SMALLINT) {// 自定义类型转换return DbColumnType.INTEGER;}return typeRegistry.getColumnType(metaInfo);});}/*** 包配置** @return 包配置*/private static Consumer<PackageConfig.Builder> getPackageConfigBuilder() {return builder ->// 设置父包名builder.parent(CONFIGURATION.getMybatisPlusConfiguration().getGenerator().getParentPackage()).entity("entity").mapper("mapper").pathInfo(Collections.singletonMap(OutputFile.xml, XML_FILE_OUTPUT_DIR));}/*** 代码生成器** @param tableName 表名*/public static void generatorMybatisPlus(String... tableName) {initPath();List<String> queryList = new ArrayList<>(List.of(tableName));logger.info(">>>> Mybatis-Plus 代码生成器，本实例只生成实体类和Mapper");logger.info(">>>> 本次生成的表名：{}", JSON.toJSONString(queryList, JSONWriter.Feature.WriteMapNullValue));FastAutoGenerator.create(CONFIGURATION.getJdbc().getUrl(), CONFIGURATION.getJdbc().getUsername(), CONFIGURATION.getJdbc().getPassword()).globalConfig(getGlobalConfigBuilder()).dataSourceConfig(getDataSourceConfigBuilder()).packageConfig(getPackageConfigBuilder()).strategyConfig(getStrategyConfigBuilder(queryList, false))// 使用Freemarker引擎模板，默认的是Velocity引擎模板.templateEngine(new FreemarkerTemplateEngine()).templateConfig(template ->// 显式禁用template.disable(TemplateType.CONTROLLER, TemplateType.SERVICE, TemplateType.SERVICE_IMPL)).execute();logger.info(">>>> 成功！！！");}/*** 代码生成器（MPJ）** @param tableName 表名*/public static void generatorMybatisPlusJoin(String... tableName) {initPath();List<String> queryList = new ArrayList<>(List.of(tableName));logger.info(">>>> Mybatis-Plus 代码生成器，本实例只生成实体类和Mapper");logger.info(">>>> 本次生成的表名：{}", JSON.toJSONString(queryList, JSONWriter.Feature.WriteMapNullValue));FastAutoGenerator.create(CONFIGURATION.getJdbc().getUrl(), CONFIGURATION.getJdbc().getUsername(), CONFIGURATION.getJdbc().getPassword()).globalConfig(getGlobalConfigBuilder()).dataSourceConfig(getDataSourceConfigBuilder()).packageConfig(getPackageConfigBuilder()).strategyConfig(getStrategyConfigBuilder(queryList, true))// 使用Freemarker引擎模板，默认的是Velocity引擎模板.templateEngine(new FreemarkerTemplateEngine()).templateConfig(template ->// 显式禁用template.disable(TemplateType.CONTROLLER, TemplateType.SERVICE, TemplateType.SERVICE_IMPL)).execute();logger.info(">>>> 成功！！！");}
}

2.3、获取 config.yml 配置

2.3.1、config.yml

jdbc:url: jdbc:mysql://localhost:3306/region?useSSL=false&useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8username: rootpassword: CWCcwy12driverClassName: com.mysql.cj.jdbc.DrivermybatisPlusConfiguration:generator:#  作者author: wxhnyfy#  代码生成目录codeDir: src/main/java#  xml文件生成目录xmlDir: src/main/resources/mapper#  entity、mapper的父包名parentPackage: com.wxhnyfy#   是否生成mapper.xml文件generateMapperXml: true#  是否使用lombokenableLombok: true#  是否使用默认的freemarker模板useDefaultFreemarkerTemplate: false#  项目名（有子模块需要填写，否则为空）projectName: ""mapperConfiguration:#  是否开启驼峰转下划线mapUnderscoreToCamelCase: true#  是否添加数据自动返回数据主键useGeneratedKeys: true# mapper接口所在路径mapperPackage: com.wxhnyfy.mapper# mapper.xml文件所在路径（resources目录下）xmlPackage: mapper

2.3.2、项目配置类

package com.wxhnyfy;import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.yaml.snakeyaml.Yaml;import java.io.InputStream;
import java.nio.charset.StandardCharsets;/*** 项目配置** @author wxhnyfy* @package com.wxhnyfy* @project maven-mybatis-plus* @date 2025/6/7*/
@Setter
@Getter
@NoArgsConstructor
@AllArgsConstructor
public class ProjectConfiguration {private static final Logger logger = LoggerFactory.getLogger(ProjectConfiguration.class);/*** 数据库连接信息*/private Jdbc jdbc;    /*** mybatis-plus配置*/private static ProjectConfiguration CONFIGURATION;/*** mybatis-plus配置*/private MybatisPlusConfiguration mybatisPlusConfiguration;/*** 获取项目配置** @return 项目配置*/public static ProjectConfiguration getConfiguration() {if (null == CONFIGURATION) {InputStream input = null;try {input = ProjectConfiguration.class.getResourceAsStream("/config.yml");if (input != null) {String yamlStr = IOUtils.toString(input, StandardCharsets.UTF_8);logger.debug(">>>> 读取配置文件内容：{}", yamlStr);Yaml yaml = new Yaml();CONFIGURATION = yaml.loadAs(yamlStr, ProjectConfiguration.class);}} catch (Exception ex) {logger.error(">>>> 读取配置文件出现错误：", ex);} finally {if (input != null) {try {input.close();} catch (Exception ex) {logger.error(">>>> 读取配置文件出现错误：", ex);}}}}return CONFIGURATION;}@Setter@Getter@NoArgsConstructor@AllArgsConstructorpublic static class Jdbc {/*** 数据库连接地址*/private String url;/*** 用户名*/private String username;/*** 密码*/private String password;/*** 驱动类*/private String driverClassName;}@Setter@Getter@NoArgsConstructor@AllArgsConstructorpublic static class MybatisPlusConfiguration {/*** 代码生成信息*/private Generator generator;/*** mapper配置信息*/private MapperConfiguration mapperConfiguration;}@Setter@Getter@NoArgsConstructor@AllArgsConstructorpublic static class Generator {/*** 是否生成mapper.xml文件*/private boolean generateMapperXml = true;/*** 是否使用lombok*/private boolean enableLombok = true;/*** 是否使用默认的freemarker模板*/private boolean useDefaultFreemarkerTemplate = false;/*** 作者*/private String author;/*** 代码生成目录*/private String codeDir;/*** xml文件生成目录*/private String xmlDir;/*** entity、mapper的父包名*/private String parentPackage;/*** 项目名（有子模块需要填写，否则为空）*/private String projectName = "";}@Setter@Getter@NoArgsConstructor@AllArgsConstructorpublic static class MapperConfiguration {/*** 是否开启驼峰转下划线*/private boolean mapUnderscoreToCamelCase = false;/*** 是否添加数据自动返回数据主键*/private boolean useGeneratedKeys = false;/*** mapper接口所在路径*/private String mapperPackage;/*** mapper.xml文件所在路径（resources目录下）*/private String xmlPackage;}
}

2.4、ftl 模板

2.4.1、实体类

package ${package.Entity};import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableName;
import com.baomidou.mybatisplus.annotation.TableId;
import lombok.*;/**
* ${table.comment!} 实体类
*
* @author ${author}
* @since ${date}
*/
@Setter
@Getter
@ToString
@NoArgsConstructor
@AllArgsConstructor
<#if table.convert>
@TableName("${table.name}")
</#if>
public class ${entity} {<#-- 遍历字段生成属性 -->
<#list table.fields as field><#if field.keyFlag><#if field.keyIdentityFlag>@TableId(value = "${field.name}", type = IdType.AUTO)<#else>@TableId("${field.name}")</#if><#else>@TableField("${field.name}")</#if>private ${field.propertyType} ${field.propertyName};</#list>
}

2.4.2、Mybatis-Plus Join Mapper 接口

package ${package.Mapper};import ${package.Entity}.${entity};
import com.github.yulichang.base.MPJBaseMapper;/**
* ${table.comment!} Mapper 接口
*
* @author ${author}
* @since ${date}
*/
public interface ${table.mapperName} extends MPJBaseMapper<${entity}> {
}

3、测试类

3.1、非线程安全

@Test
public void testSqlSession() {SqlSession session = GetSqlSession.getMybatisPlusSqlSession();AmapRegionMapper amapRegionMapper = session.getMapper(AmapRegionMapper.class);List<AmapRegion> list = amapRegionMapper.selectList(new Page<>(1, 100),new LambdaQueryWrapper<AmapRegion>().eq(AmapRegion::getLevel, "province"));for (AmapRegion amapRegion : list) {logger.debug(">>> {}", JSON.toJSONString(amapRegion, JSONWriter.Feature.WriteMapNullValue));}GetSqlSession.cleanSqlSession();session.commit();session.close();
}

3.2、线程安全

@Test
public void testSqlSessionManager() {SqlSessionManager sqlSessionManager = GetSqlSession.safeMybatisPlusSqlSession();// 开启session管理sqlSessionManager.startManagedSession(true);AmapRegionMapper amapRegionMapper = sqlSessionManager.getMapper(AmapRegionMapper.class);List<AmapRegion> amapRegionList = amapRegionMapper.selectList(new Page<>(1, 100),new LambdaQueryWrapper<AmapRegion>().eq(AmapRegion::getLevel, "province"));for (AmapRegion amapRegion : amapRegionList) {logger.debug(">>> {}", JSON.toJSONString(amapRegion, JSONWriter.Feature.WriteMapNullValue));}GetSqlSession.cleanSqlSessionManager();//  提交sqlSessionManager.commit();sqlSessionManager.close();
}

3.3、MybatisPlusJoin

@Test
public void testMybatisPlusJoin() {SqlSessionManager sqlSessionManager = GetSqlSession.safeMybatisPlusJoinSqlSession();sqlSessionManager.startManagedSession();ChinaMcaRegionMapper mapper = sqlSessionManager.getMapper(ChinaMcaRegionMapper.class);long total = mapper.selectJoinCount(new MPJLambdaWrapper<ChinaMcaRegion>("l1").leftJoin(ChinaMcaRegion.class, "l2", ChinaMcaRegion::getParentid, "l1", ChinaMcaRegion::getId).leftJoin(ChinaMcaRegion.class, "l3", ChinaMcaRegion::getParentid, "l2", ChinaMcaRegion::getId).eq("l1.level", "0").orderBy(true, true, "l1.code", "l2.code", "l3.code"));logger.info(">>> total: {}", total);long pageSize = 200;logger.info(">>> pageSize: {}", pageSize);long pageCount = (total / pageSize) + (total % pageSize == 0 ? 0 : 1);logger.info(">>> pageCount: {}", pageCount);long pageNum = 8;logger.info(">>> pageNum: {}", pageNum);List<Map<String, Object>> resultPage = mapper.selectJoinMaps(new MPJLambdaWrapper<ChinaMcaRegion>("l1").select("IF (( length( `l1`.`code` ) >= 6 ), `l1`.`code`, NULL ) AS `省级行政区编码`","`l1`.`name` AS `省/自治区/直辖市/特别行政区`","IF (( length( `l2`.`code` ) >= 6 ), `l2`.`code`, NULL ) AS `地级行政区编码`","`l2`.`name` AS `地级市/地区/自治州/盟`","IF (( length( `l3`.`code` ) >= 6 ), `l3`.`code`, NULL ) AS `县级行政区编码`","`l3`.`name` AS `市辖区/县级市/县/自治县/旗/自治旗/特区/林区`","( CASE WHEN ( ifnull( `l2`.`name`, '' ) = '' ) THEN " +"concat( '中国/', `l1`.`name` ) " +"WHEN ( ifnull( `l3`.`name`, '' ) = '' ) THEN " +"concat( '中国/', `l1`.`name`, '/', `l2`.`name` ) ELSE concat( '中国/', `l1`.`name`, '/', `l2`.`name`, '/', `l3`.`name` ) " +"END " +") AS `全路径名称`").leftJoin(ChinaMcaRegion.class, "l2", ChinaMcaRegion::getParentid, "l1", ChinaMcaRegion::getId).leftJoin(ChinaMcaRegion.class, "l3", ChinaMcaRegion::getParentid, "l2", ChinaMcaRegion::getId).eq("l1.level", "0").orderBy(true, true, "l1.code", "l2.code", "l3.code").last("limit " + (pageNum - 1) * pageSize + "," + pageSize));logger.info(">>> resultPage.size(): {}", resultPage.size());for (Map<String, Object> row : resultPage) {logger.info(">>> {}", JSON.toJSONString(row, JSONWriter.Feature.WriteMapNullValue));}GetSqlSession.cleanSqlSessionManager();sqlSessionManager.commit();sqlSessionManager.close();
}

3.4、代码生成器

@Test
public void generatorTable() {MybatisPlusGenerator.generatorMybatisPlus("amap_region", "baidu_map");MybatisPlusGenerator.generatorMybatisPlusJoin("china_mca_region");
}