一. springboot+mybatis-plus+druid实现动态数据源以及监控

1. 创建一个springboot项目dynamic-db，数据库以mysql为例

init springboot
dynamic-db

2. 引入依赖jar包

• 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>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>dynamic-db</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>dynamic-db</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <mybatis-plus.version>3.2.0</mybatis-plus.version>
        <druid.version>1.1.21</druid.version>
        <p6spy.version>3.8.6</p6spy.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>${druid.version}</version>
        </dependency>
        <dependency>
            <groupId>p6spy</groupId>
            <artifactId>p6spy</artifactId>
            <version>${p6spy.version}</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>${mybatis-plus.version}</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

3. 配置application.yml，添加多个数据源连接属性

server:
  port: 8080
spring:
  aop:
    proxy-target-class: true
    auto: true
  datasource:
    db1:
      driver-class-name: com.p6spy.engine.spy.P6SpyDriver  ## 也可以使用mysql官方驱动，这里替换成p6spy驱动方便打印sql日志
      url: jdbc:p6spy:mysql://mysql-dev.database:3306/dynamic-source?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false
      username: root
      password: 123456
      db-type: mysql
      validation-query: "select 1"
      max-active: 16
      min-idle: 4
    db2:
      driver-class-name: com.p6spy.engine.spy.P6SpyDriver
      url: jdbc:p6spy:mysql://mysql-dev.database:3306/dynamic-target?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false
      username: root
      password: 123456
      db-type: mysql
      validation-query: "select 1"
    druid:  # druid 监控配置
      filter:
        stat:
          enabled: true  #是否激活sql监控
        wall:
          enabled: true  #是否激活sql防火墙
      web-stat-filter:
        enabled: true
      stat-view-servlet:
        enabled: true
        url-pattern: "/druid/*"   #浏览器访问localhost:8080/druid，进入监控界面
        login-username: admin
        login-password: admin@123

4.创建datasource相关配置类

• DbGlobal

/**
 * @Author: He Zhigang
 * @Date: 2019/12/15 12:14
 * @Description:
 */
public class DbGlobal {

    /**
     * 第一个数据源自动生成的包名名称
     */
    public static final String DB1 = "source";
    /**
     * 第二个数据源自动生成的包名名称
     */
    public static final String DB2 = "target";

    //TODO 跟多数据源继续添加DB3，DB4,...
    
}

• DataSourceContextHolder

/**
 * @Author: He Zhigang
 * @Date: 2019/12/10 12:45
 * @Description: 数据源上线文
 */
public class DataSourceContextHolder {
    /**
     * 实际上就是开启多个线程，每个线程进行初始化一个数据源
     */
    private static final ThreadLocal<String> CONTEXT_HOLDER = new ThreadLocal<>();

    /**
     * 取得当前数据源
     *
     * @return
     */
    public static String getDbType() {
        return CONTEXT_HOLDER.get();
    }

    /**
     * 设置数据源
     *
     * @param dbEnum
     */
    public static void setDbType(String dbEnum) {
        CONTEXT_HOLDER.set(dbEnum);
    }

    /**
     * 清除上下文数据
     */
    public static void clearDbType() {
        CONTEXT_HOLDER.remove();
    }
}

• DynamicDataSource

import lombok.extern.slf4j.Slf4j;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

/**
 * @Author: He Zhigang
 * @Date: 2019/12/10 12:44
 * @Description: 动态路由数据源
 */
@Slf4j
public class DynamicDataSource extends AbstractRoutingDataSource {
    @Override
    protected Object determineCurrentLookupKey() {
        String datasource = DataSourceContextHolder.getDbType();
        log.debug("使用数据源 {}", datasource);
        return datasource;
    }
}

• MybatisPlusConfig

import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;
import com.baomidou.mybatisplus.core.MybatisConfiguration;
import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.type.JdbcType;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;

/**
 * @Author: He Zhigang
 * @Date: 2019/12/10 12:41
 * @Description:
 */
@EnableTransactionManagement
@Configuration
@MapperScan("com.example.dynamicdb.*.mapper") // 扫描mapperdao的地址
public class MybatisPlusConfig {

    @Bean
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }

    @Bean(name = DbGlobal.DB1)
    @ConfigurationProperties(prefix = "spring.datasource.db1")
    public DataSource source() {
        return DruidDataSourceBuilder.create().build();
    }

    @Bean(name = DbGlobal.DB2)
    @ConfigurationProperties(prefix = "spring.datasource.db2")
    public DataSource target() {
        return DruidDataSourceBuilder.create().build();
    }

    /**
     * 动态数据源配置
     *
     * @return
     */
    @Bean
    @Primary
    public DataSource multipleDataSource(@Qualifier(DbGlobal.DB1) DataSource source,
                                         @Qualifier(DbGlobal.DB2) DataSource target) {
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put(DbGlobal.DB1, source);
        targetDataSources.put(DbGlobal.DB2, target);
        dynamicDataSource.setTargetDataSources(targetDataSources);
        // 程序默认数据源，这个要根据程序调用数据源频次，经常把常调用的数据源作为默认
        dynamicDataSource.setDefaultTargetDataSource(source);
        return dynamicDataSource;
    }

    @Bean("sqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory() throws Exception {
        MybatisSqlSessionFactoryBean sqlSessionFactory = new MybatisSqlSessionFactoryBean();
        sqlSessionFactory.setDataSource(multipleDataSource(source(), target()));

        MybatisConfiguration configuration = new MybatisConfiguration();
        configuration.setJdbcTypeForNull(JdbcType.NULL);
        configuration.setMapUnderscoreToCamelCase(true);
        configuration.setCacheEnabled(false);
        sqlSessionFactory.setConfiguration(configuration);
        // 乐观锁插件
        //PerformanceInterceptor(),OptimisticLockerInterceptor()
        // 分页插件
        sqlSessionFactory.setPlugins(paginationInterceptor());
        return sqlSessionFactory.getObject();
    }
}

• DataSourceAspect

import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

/**
 * @Author: He Zhigang
 * @Date: 2019/12/10 12:55
 * @Description: AOP拦截动态切换数据源
 */
@Component
@Order(value = -100)
@Slf4j
@Aspect
public class DataSourceAspect {
    @Pointcut("execution(* com.example.dynamicdb."+ DbGlobal.DB1+".mapper..*.*(..))")
    private void sourceAspect() {
    }

    @Pointcut("execution(* com.example.dynamicdb."+ DbGlobal.DB2+".mapper..*.*(..))")
    private void targetAspect() {
    }

    @Before("sourceAspect()")
    public void source() {
        log.info("切换到{} 数据源...",DbGlobal.DB1);
        DataSourceContextHolder.setDbType(DbGlobal.DB1);
    }

    @Before("targetAspect()")
    public void target() {
        log.info("切换到{} 数据源...",DbGlobal.DB2);
        DataSourceContextHolder.setDbType(DbGlobal.DB2);
    }
}

最后，在把p6spy的配置文件加上

#3.2.1以上使用
#modulelist=com.baomidou.mybatisplus.extension.p6spy.MybatisPlusLogFactory,com.p6spy.engine.outage.P6OutageFactory
#3.2.1以下使用或者不配置
modulelist=com.p6spy.engine.logging.P6LogFactory,com.p6spy.engine.outage.P6OutageFactory
# 自定义日志打印
logMessageFormat=com.baomidou.mybatisplus.extension.p6spy.P6SpyLogger
#日志输出到控制台
appender=com.baomidou.mybatisplus.extension.p6spy.StdoutLogger
# 使用日志系统记录 sql
#appender=com.p6spy.engine.spy.appender.Slf4JLogger
# 设置 p6spy driver 代理
deregisterdrivers=true
# 取消JDBC URL前缀
useprefix=true
# 配置记录 Log 例外,可去掉的结果集有error,info,batch,debug,statement,commit,rollback,result,resultset.
excludecategories=info,debug,result,commit,resultset
# 日期格式
dateformat=yyyy-MM-dd HH:mm:ss
# 实际驱动可多个
driverlist=com.mysql.cj.jdbc.Driver
# 是否开启慢SQL记录
outagedetection=true
# 慢SQL记录标准 2 秒
outagedetectioninterval=2

以上，就能实现动态数据源的切换了，注释都在代码里面都十分清楚了。

目录结构

不出意外的话启动后访问 http://localhost:8080/druid/index.html 就可以看到druid提供的监控页面了。
源码地址：https://github.com/DimonHo/dynamic-db/tree/no-auto-generator

---

二. 自动生成代码

一般我用到动态数据都是源于数据迁移的需求，这就表示数据库一般是已经建好了的，里面可能已经有了几十上百个表，如果要一个一个手动创建与表对应的entity工作量可能有点大。现在我们再来看看如何利用com.baomidou:mybatis-plus-generator:3.2.0来给我们自动生成数据库里面已有表对应的实体类。

1. 在上面的项目基础上，我们再到pom.xml中添加两个jar包

        <!--国内超级好用的一个util包，囊括了常用的工具方法-->
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>${hutool.version}</version>
        </dependency>
        <!--自动生成代码-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>${mybatis-plus.version}</version>
        </dependency>

2. 我们创建一个自动生成代码的类

根据官方示例代码 https://mybatis.plus/guide/generator.html 修改
我们首先创建一个配置类auto-generator.properties，把相关可以自定义的配置放入配置文件里面，方便修改。

• 新建auto-generator.properties配置文件

## 输出路径,默认：D：\\。 多模块项目需要加上项目名称： \\dynamic-db/src/main/java
global.outputDir=/src/main/java
global.fileOverride=false
global.open=false
global.author=DimonHo
global.baseResultMap=true
global.baseColumnList=true
global.swagger=false

## 自定义service类名称,默认:I%sService
global.serviceName=%sService
## 自定义controller类名称,默认:%sController
global.controllerName=
## 自定义mapper类名称,默认:%sMapper
global.mapperName=
## 自定义mapper xml名称,默认:%sMapper
global.xmlName=
## 自定义service实现类名称,默认:%ServiceImpl
global.serviceImplName=
global.entityName=
## 是否在xml中添加二级缓存配置
global.enableCache=true

## 模板引擎类型：默认velocity,可选值：freemarker,beetl
injection.templateType=freemarker

package.parent=com.example.dynamicdb
package.controller=controller
package.entity=entity
package.mapper=mapper
package.service=service
package.serviceImpl=service.impl

## 指定相关父类
strategy.superEntityClass=
strategy.superControllerClass=com.example.dynamicdb.controller.BaseController
## 指定父类Entity中的字段，多个以","分隔
strategy.superEntityColumns=

• 新建 CustomMetaObjectHandler

import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.stereotype.Component;

import java.util.Date;

/**
 * @Author: He Zhigang
 * @Date: 2019/12/11 20:30
 * @Description: 自定义自动填充字段处理策略
 */
@Slf4j
@Component
public class CustomMetaObjectHandler implements MetaObjectHandler {

    @Override
    public void insertFill(MetaObject metaObject) {
        log.info("start insert fill ....");
        this.setFieldValByName("gmtCreate", new Date(), metaObject);
        this.setFieldValByName("gmtModified", new Date(), metaObject);
    }

    @Override
    public void updateFill(MetaObject metaObject) {
        log.info("start update fill ....");
        this.setFieldValByName("gmtModified", new Date(), metaObject);
    }
}

• 修改DataSourceContextHolder，在其中中添加一个常量：

    /**
     * 保存所有的数据源
     */
    public static final Map<String, DataSource> DATA_SOURCE_MAP = new HashMap<>();

• 在DbGlobal中再添加几个配置字段

    /**
     * 需要自动生成的表，为空表示全部生成，与STRATEGY_EXCLUDE不能同时设置
     */
    public static final Map<String, String[]> STRATEGY_INCLUDE = MapUtil.builder(DB1, new String[]{})
            .put(DB2, new String[]{})
            //TODO put DB3,...
            .build();

    /**
     * 排除自动生成的表，为空表示不排除，与STRATEGY_INCLUDE不能同时设置
     */
    public static final Map<String, String[]> STRATEGY_EXCLUDE = MapUtil.builder(DB1, new String[]{"scopus_journal","scopus_journal2","t_update_log","t_journal_metadata"})
            .put(DB2, new String[]{})
            //TODO put DB3,...
            .build();

    /**
     * 数据源DB1中需要自动填充的字段
     */
    public static final List<TableFill> DB1_TABLE_FILL = CollectionUtil.newArrayList(
            new TableFill("gmt_create", FieldFill.INSERT),
            new TableFill("gmt_modified", FieldFill.INSERT_UPDATE)
            //TODO new TableFill("columnName",FieldFill),...
    );

    /**
     * 数据源DB2中需要填充的字段
     */
    public static final List<TableFill> DB2_TABLE_FILL = CollectionUtil.newArrayList(
            new TableFill("gmt_create", FieldFill.INSERT),
            new TableFill("gmt_modified", FieldFill.INSERT_UPDATE)
            //TODO new TableFill("columnName",FieldFill),...
    );

    public static final Map<String, List<TableFill>> STRATEGY_TABLE_FILL = MapUtil.builder(DB1, DB1_TABLE_FILL)
            //TODO put(DB2,DB2_TABLE_FILL),...
            .build();

• 新建 AutoGeneratorBean

import cn.hutool.core.collection.CollectionUtil;
import cn.hutool.core.text.StrSpliter;
import cn.hutool.core.util.ArrayUtil;
import cn.hutool.core.util.StrUtil;
import com.alibaba.druid.pool.DruidDataSource;
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.DateType;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;
import java.util.ArrayList;
import java.util.List;
import java.util.ResourceBundle;

/**
 * @Author: He Zhigang
 * @Date: 2019/12/11 9:29
 * @Description:
 */
@Slf4j
@Configuration
@ConditionalOnClass(value = AutoGenerator.class)
@ConditionalOnProperty(prefix = "mybatis-plus", name = "auto-generator", havingValue = "true")
public class AutoGeneratorBean implements ApplicationRunner {

    /**
     * auto_generator配置文件名称，位于resources目录下
     */
    private static final String AUTO_GENERATOR = "auto-generator";

    @Override
    public void run(ApplicationArguments args) throws Exception {
        //读取配置文件
        ResourceBundle rb = ResourceBundle.getBundle(AUTO_GENERATOR);
        DataSourceContextHolder.DATA_SOURCE_MAP.forEach((db, datasource) -> {
            log.info(db + "模块自动创建开始。。。");
            String projectPath = System.getProperty("user.dir");
            // 代码生成器
            AutoGenerator mpg = new AutoGenerator();
            mpg.setGlobalConfig(globalConfig(rb, projectPath))
                    .setDataSource(dataSourceConfig(datasource))
                    .setPackageInfo(packageConfig(rb, db))
                    .setCfg(InjectionConfig(rb, db, projectPath))
                    .setTemplate(templateConfig())
                    .setStrategy(strategyConfig(rb, db))
                    .setTemplateEngine(new FreemarkerTemplateEngine())
                    .execute();
            log.info(db + "模块自动创建完成！");
        });
    }

    private InjectionConfig InjectionConfig(ResourceBundle rb, String db, String projectPath) {
        InjectionConfig cfg = new InjectionConfig() {
            @Override
            public void initMap() {
                // to do nothing
            }
        };
        //模板引擎默认是velocity,可选freemarker,beetl
        String templatePath = "/templates/mapper.xml";
        switch (rb.getString("injection.templateType")) {
            case "freemarker":
                templatePath = templatePath + ".ftl";
                break;
            case "beetl":
                templatePath = templatePath + ".btl";
                break;
            default:
                templatePath = templatePath + ".vm";
        }
        // 自定义输出配置
        List<FileOutConfig> 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 ， 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 projectPath + "/src/main/resources/mapper/" + db
                        + "/" + String.format(StrUtil.blankToDefault(rb.getString("global.xmlName"), "%sMapper"), tableInfo.getEntityName()) + StringPool.DOT_XML;
            }
        });
        cfg.setFileOutConfigList(focList);
        return cfg;
    }

    /**
     * 配置模板
     *
     * @return
     */
    private TemplateConfig templateConfig() {
        TemplateConfig templateConfig = 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
        templateConfig.setXml(null);
        return templateConfig;
    }

    private StrategyConfig strategyConfig(ResourceBundle rb, String db) {
        StrategyConfig strategy = new StrategyConfig()
                .setNaming(NamingStrategy.underline_to_camel)
                .setColumnNaming(NamingStrategy.underline_to_camel)
                .setEntityLombokModel(true)
                .setRestControllerStyle(true)
                .setControllerMappingHyphenStyle(true)
                .setTablePrefix(db + "_");
        if (ArrayUtil.isNotEmpty(DbGlobal.STRATEGY_INCLUDE.get(db))) {
            strategy.setInclude(DbGlobal.STRATEGY_INCLUDE.get(db));
        } else if (ArrayUtil.isNotEmpty(DbGlobal.STRATEGY_EXCLUDE.get(db))) {
            strategy.setExclude(DbGlobal.STRATEGY_EXCLUDE.get(db));
        }
        if (CollectionUtil.isNotEmpty(DbGlobal.STRATEGY_TABLE_FILL.get(db))) {
            strategy.setTableFillList(DbGlobal.STRATEGY_TABLE_FILL.get(db));
        }
        if (StrUtil.isNotBlank(rb.getString("strategy.superEntityClass"))) {
            strategy.setSuperEntityClass(rb.getString("strategy.superEntityClass"));
            if (StrUtil.isNotBlank(rb.getString("strategy.superEntityColumns"))) {
                // 写于父类中的公共字段
                strategy.setSuperEntityColumns(StrSpliter.splitToArray(rb.getString("strategy.superEntityColumns"), ",", 0, true, true));
            }
        }
        strategy.setSuperControllerClass(rb.getString("strategy.superControllerClass"));
        return strategy;
    }

    private PackageConfig packageConfig(ResourceBundle rb, String db) {
        return new PackageConfig()
                .setParent(rb.getString("package.parent"))
                .setModuleName(db)
                .setController(StrUtil.blankToDefault(rb.getString("package.controller"), "controller"))
                .setEntity(StrUtil.blankToDefault(rb.getString("package.entity"), "entity"))
                .setMapper(StrUtil.blankToDefault(rb.getString("package.mapper"), "mapper"))
                .setService(StrUtil.blankToDefault(rb.getString("package.service"), "service"))
                .setServiceImpl(StrUtil.blankToDefault(rb.getString("package.serviceImpl"), "service.impl"));
    }

    private DataSourceConfig dataSourceConfig(DataSource datasource) {
        DruidDataSource ds = (DruidDataSource) datasource;
        return new DataSourceConfig()
                .setUrl(ds.getUrl())
                .setDriverName(ds.getDriverClassName())
                .setUsername(ds.getUsername())
                .setPassword(ds.getPassword());
    }

    private GlobalConfig globalConfig(ResourceBundle rb, String projectPath) {
        return new GlobalConfig()
                .setOutputDir(projectPath + rb.getString("global.outputDir"))
                .setFileOverride(Boolean.parseBoolean(rb.getString("global.fileOverride")))
                .setAuthor(rb.getString("global.author"))
                .setControllerName(rb.getString("global.controllerName"))
                .setEntityName(rb.getString("global.entityName"))
                .setMapperName(rb.getString("global.mapperName"))
                .setXmlName(rb.getString("global.xmlName"))
                .setServiceName(rb.getString("global.serviceName"))
                .setServiceImplName(rb.getString("global.serviceImplName"))
                .setEnableCache(Boolean.parseBoolean(rb.getString("global.enableCache")))
                .setSwagger2(Boolean.parseBoolean(rb.getString("global.swagger")))
                .setBaseColumnList(Boolean.parseBoolean(rb.getString("global.baseColumnList")))
                .setBaseResultMap(Boolean.parseBoolean(rb.getString("global.baseResultMap")))
                .setDateType(DateType.ONLY_DATE)
                .setOpen(Boolean.parseBoolean(rb.getString("global.open")));
    }
}

• 修改MybatisPlusConfig

    @Autowired
    CustomMetaObjectHandler customMetaObjectHandler;

    /**
     * 动态数据源配置
     *
     * @return
     */
    @Bean
    @Primary
    public DataSource multipleDataSource(@Qualifier(DbGlobal.DB1) DataSource source,
                                         @Qualifier(DbGlobal.DB2) DataSource target) {
        DynamicDataSource dynamicDataSource = new DynamicDataSource();

        // 将所有的数据源放入map，后面遍历Map，对其中所有的数据源自动生成代码 start======
        DataSourceContextHolder.DATA_SOURCE_MAP.put(DbGlobal.DB1, source);
        DataSourceContextHolder.DATA_SOURCE_MAP.put(DbGlobal.DB2, target);
        // 将所有的数据源放入map，后面遍历Map，对其中所有的数据源自动生成代码 end======

        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put(DbGlobal.DB1, source);
        targetDataSources.put(DbGlobal.DB2, target);
        dynamicDataSource.setTargetDataSources(targetDataSources);
        // 程序默认数据源，这个要根据程序调用数据源频次，经常把常调用的数据源作为默认
        dynamicDataSource.setDefaultTargetDataSource(source);
        return dynamicDataSource;
    }

    @Bean("sqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory() throws Exception {
        MybatisSqlSessionFactoryBean sqlSessionFactory = new MybatisSqlSessionFactoryBean();
        sqlSessionFactory.setDataSource(multipleDataSource(source(), target()));

        MybatisConfiguration configuration = new MybatisConfiguration();
        configuration.setJdbcTypeForNull(JdbcType.NULL);
        configuration.setMapUnderscoreToCamelCase(true);
        configuration.setCacheEnabled(false);
        sqlSessionFactory.setConfiguration(configuration);
        //PerformanceInterceptor(),OptimisticLockerInterceptor()
        //添加分页功能
        sqlSessionFactory.setPlugins(paginationInterceptor());
        // 设置自动填充策略 start========
        GlobalConfig globalConfig = new GlobalConfig();
        globalConfig.setMetaObjectHandler(customMetaObjectHandler);
        sqlSessionFactory.setGlobalConfig(globalConfig);
        // 设置自动填充策略 end========
        return sqlSessionFactory.getObject();
    }

• 新建一个BaseController抽象类，所有的controller集成该类，可自动生成你所需要的基础rest接口

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.IService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

/**
 * @Author: He Zhigang
 * @Date: 2019/12/10 16:17
 * @Description:
 */
public abstract class BaseController<T> {

    @Autowired
    public IService<T> service;

    @PostMapping()
    public Object add(@RequestBody T t) {
        return service.save(t);
    }

    @PutMapping()
    public Object update(@RequestBody T t) {
        return service.updateById(t);
    }

    @GetMapping("/{id}")
    public T get(@PathVariable Long id) {
        return service.getById(id);
    }

    @GetMapping()
    public IPage<T> find(@RequestParam(required = false,defaultValue = "0") Integer page,
                         @RequestParam(required = false,defaultValue = "10") Integer size) {
        Page<T> pageable = new Page<>(page, size);
        return service.page(pageable, new QueryWrapper<T>().orderByDesc("id"));
    }
}

• 在resource/templates目录下创建congtroller.java.ftl模板

package ${package.Controller};

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.beans.factory.annotation.Autowired;
import ${package.Entity}.${entity};
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 swagger2>
import io.swagger.annotations.ApiOperation;
import org.springframework.web.bind.annotation.*;
</#if>

/**
* <p>
    * ${table.comment!} 前端控制器
    * </p>
*
* @author ${author}
* @since ${date}
*/
<#if restControllerStyle>
@RestController
<#else>
@Controller
</#if>
@RequestMapping("<#if package.ModuleName??>/${package.ModuleName}</#if>/<#if controllerMappingHyphenStyle??>${controllerMappingHyphen}<#else>${table.entityPath}</#if>")
<#if superControllerClass??>
public class ${table.controllerName} extends ${superControllerClass}<${entity}> {
<#else>
public class ${table.controllerName} {
</#if>

}

• 在application.yml中添加自动生成代码配置开关

mybatis-plus:
  auto-generator: true#自动生成代码开关，缺省false

以上准备工作做好后，Just run it!
注意：第一次启动生成完代码后，再重启一次，生成的代码才能生效。
源码地址：https://github.com/DimonHo/dynamic-db/tree/auto-generator

目录结构

自动生成代码目录结构：

image.png
此时，你可以直接访问 http://localhost:8080/[数据源名称]/[表名] 就可以返回数据表的数据了
如：http://localhost:8080/source/user