Spring Boot 项目使用 Mybatis_如何判断java项目中有没有使用mydatis-plus

application.yml文件里配置数据源，可多个

# 数据库1
spring.datasource.test1.url: jdbc:mysql://ip1:port1/test1?autoReconnect=true&characterEncoding=UTF-8&useTimezone=true&serverTimezone=GMT%2B8
spring.datasource.test1.username: test1
spring.datasource.test1.password: test1
spring.datasource.test1.driver-class-name: com.mysql.cj.jdbc.Driver
 
# 数据库2
spring.datasource.test2.url: jdbc:mysql://ip2:port2/test2?autoReconnect=true&characterEncoding=UTF-8&useTimezone=true&serverTimezone=GMT%2B8
spring.datasource.test2.username: test2
spring.datasource.test2.password: test2
spring.datasource.test2.driver-class-name: com.mysql.cj.jdbc.Driver
 
# 通用连接池配置
spring.datasource.type: com.alibaba.druid.pool.DruidDataSource
spring.datasource.initialSize: 5
spring.datasource.minIdle: 5
spring.datasource.maxActive: 20
spring.datasource.maxWait: 60000
spring.datasource.timeBetweenEvictionRunsMillis: 60000
spring.datasource.validationQuery: SELECT 1
spring.datasource.testWhileIdle: true
spring.datasource.testOnBorrow: false
spring.datasource.testOnReturn: false
spring.datasource.poolPreparedStatements: true
spring.datasource.maxPoolPreparedStatementPerConnectionSize: 20
spring.datasource.filters: stat
spring.datasource.connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000

根据配置的数据库个数，创建对应个数的连接配配置类：

1.常规读取mapper文件的配置

@Configuration
@MapperScan(basePackages = "com.xxx.datasource.test1.mapper", sqlSessionTemplateRef = "test1SqlSessionTemplate")
public class Test1Datasource {
 
    @Bean(name = "test1DataSource")
    @Primary
    public DataSource getDataSource(Environment env) throws Exception {
        Properties props = new Properties();
        props.put("driverClassName", env.getProperty("spring.datasource.test1.driver-class-name"));
        props.put("url", env.getProperty("spring.datasource.test1.url"));
        props.put("username", env.getProperty("spring.datasource.test1.username"));
        props.put("password", env.getProperty("spring.datasource.test1.password"));
        return DruidDataSourceFactory.createDataSource(props);
    }
 
    @Bean(name = "test1SqlSessionFactory")
    public SqlSessionFactory getSqlSessionFactory(@Qualifier("test1DataSource") DataSource dataSource)
        throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        // 设置mybatis的主配置文件 记住是主配置文件啊
        ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        // 设置mapper.xml文件的路径 {resourceMapXML};
        Resource[] resource = resolver.getResources("classpath*:mapper/*.xml");
        bean.setMapperLocations(resource);
        return bean.getObject();
    }
 
    @Bean(name = "test1TransactionManager")
    @Primary
    public DataSourceTransactionManager getTransactionManager(@Qualifier("test1DataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }
 
    @Bean(name = "test1SqlSessionTemplate")
    @Primary
    public SqlSessionTemplate
        getSqlSessionTemplate(@Qualifier("test1SqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

2.使用mybatis-plus时的配置

@Configuration
@MapperScan(basePackages = "com.xxx.datasource.test2.mapper", sqlSessionFactoryRef = "test2SqlSessionFactory")
public class Test2PlusDataSource {
 
    @Bean(name = "test2PlusDataSource")
    public DataSource getDataSource(Environment env) throws Exception {
        Properties props = new Properties();
        props.put("driverClassName", env.getProperty("spring.datasource.test2.driver-class-name"));
        props.put("url", env.getProperty("spring.datasource.test2.url"));
        props.put("username", env.getProperty("spring.datasource.test2.username"));
        props.put("password", env.getProperty("spring.datasource.test2.password"));
        return DruidDataSourceFactory.createDataSource(props);
    }
 
    /**
     * mybatis-plus分页插件
     */
    @Bean(name = "test2PaginationInterceptor")
    public Interceptor paginationInterceptor() {
        PaginationInterceptor page = new PaginationInterceptor();
        page.setDialectType("mysql");
        return page;
    }
 
    /**
     * 注入mybatis的 DatabaseIdProvider 作为一个bean,方便被引用
     * 
     * @return bean
     */
    @Bean
    public DatabaseIdProvider getDatabaseIdProvider() {
        return new DefaultDatabaseIdProvider();
    }
 
 
 
    /**
     * 这里全部使用mybatis-autoconfigure 已经自动加载的资源。不手动指定 配置文件和mybatis-boot的配置文件同步 采用多参数注入方式，避免通过autowired注入导致的报错
     * 
     * @param dataSource 注入数据源
     * @param databaseIdProvider 注入DatabaseIdProvider
     * @param properties 注入 MybatisPlusProperties
     * @param interceptors 注入 Interceptor 主要为分页信息
     * @return MybatisSqlSessionFactoryBean
     * @throws IOException IOException
     */
    @Bean(name = "test2SqlSessionFactory")
    public MybatisSqlSessionFactoryBean test2SqlSessionFactoryBean(
        @Qualifier("test2PlusDataSource") DataSource dataSource, DatabaseIdProvider databaseIdProvider,
        MybatisPlusProperties properties, Interceptor[] interceptors) throws IOException {
        MybatisSqlSessionFactoryBean mybatisPlus = new MybatisSqlSessionFactoryBean();
        try {
            mybatisPlus.setDataSource(dataSource);
        } catch (Exception e) {
            log.error(ExceptionUtils.getStackTrace(e));
        }
        //DefaultVFS在获取jar上存在问题，使用springboot
        //SpringBoot完整包部署，手动设置SpringBootVFS
        mybatisPlus.setVfs(SpringBootVFS.class);
        // 设置分页插件
        if (interceptors != null) {
            mybatisPlus.setPlugins(interceptors);
        }
 
        MybatisConfiguration mc = new MybatisConfiguration();
        mc.setDefaultScriptingLanguage(MybatisXMLLanguageDriver.class);
        // 数据库和java都是驼峰，就不需要
        mc.setMapUnderscoreToCamelCase(true);
        mybatisPlus.setConfiguration(mc);
 
        if (databaseIdProvider != null) {
            mybatisPlus.setDatabaseIdProvider(databaseIdProvider);
        }
 
        mybatisPlus.setTypeAliasesPackage("com.xxx.entity.test2");
        if (properties != null) {
            mybatisPlus.setTypeHandlersPackage(properties.getTypeHandlersPackage());
            mybatisPlus.setMapperLocations(properties.resolveMapperLocations());
        }
        // 设置mapper.xml文件的路径
        ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        Resource[] resource = resolver.getResources("classpath:mapper/test2/**/*.xml");
        mybatisPlus.setMapperLocations(resource);
 
        return mybatisPlus;
    }
 
    @Bean(name = "test2MpTransactionManager")
    public DataSourceTransactionManager getTransactionManager(@Qualifier("test2PlusDataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }
}