项目Git地址：SpringBoot 配置多数据源：Jacob-multi-data-source

1. 准备工作
   准备两个数据库(此模块中两个数据库一个为本地 一个为远程，本地为主，远程为从)。然后建表。

#本地库
CREATE TABLE `username` (`id` bigint(11) NOT NULL AUTO_INCREMENT,`username` varchar(255) NOT NULL,`password` varchar(255) NOT NULL,PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;
#远程库
CREATE TABLE `user` (`id` bigint NOT NULL COMMENT '主键ID',`name` varchar(30) DEFAULT NULL COMMENT '姓名',`age` int DEFAULT NULL COMMENT '年龄',`email` varchar(50) DEFAULT NULL COMMENT '邮箱',PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

1. 创建SpringBoot项目
   最终目录结构：

1. 添加依赖

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><scope>runtime</scope></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.1.0</version></dependency><dependency><groupId>cn.hutool</groupId><artifactId>hutool-all</artifactId><version>5.1.0</version></dependency><dependency><groupId>io.springfox</groupId><artifactId>springfox-swagger2</artifactId><version>2.9.2</version></dependency><dependency><groupId>com.github.xiaoymin</groupId><artifactId>swagger-bootstrap-ui</artifactId><version>1.9.6</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.0.18</version></dependency>

1. 编写配置文件

server:port: 8083swagger:enabled: truemybatis:mapper-locations: classpath:mapper/*/*.xml,classpath:mapper/*.xml
## 主数据源
master:package: cn.jacob.datasource.mapper.masterdatasource:url: jdbc:mysql://localhost:3306/tst?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&serverTimezone=UTCusername: rootpassword:driverClassName: com.mysql.cj.jdbc.Driver
## 从数据源
cluster:datasource:url: jdbc:mysql://121.36.9.198:3306/local?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&serverTimezone=UTCusername: rootpassword:driverClassName: com.mysql.cj.jdbc.Driver# -------------------------------------这一块配置不加会导致项目启动很慢-------------------------------------
# 连接池的配置信息
# 初始化大小，最小，最大
spring:datasource:type: com.alibaba.druid.pool.DruidDataSourceinitialSize: 5minIdle: 5maxActive: 20# 配置获取连接等待超时的时间maxWait: 60000# 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒timeBetweenEvictionRunsMillis: 60000# 配置一个连接在池中最小生存的时间，单位是毫秒minEvictableIdleTimeMillis: 300000validationQuery: SELECT 1 FROM DUALtestWhileIdle: truetestOnBorrow: falsetestOnReturn: false# 打开PSCache，并且指定每个连接上PSCache的大小poolPreparedStatements: truemaxPoolPreparedStatementPerConnectionSize: 20# 配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙filters: stat,wall,log4j# 通过connectProperties属性来打开mergeSql功能；慢SQL记录connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
# -------------------------------------------------------------------------------------------------------

1. 编写配置类
   swagger配置类

@Configuration@EnableSwagger2public class SwaggerConfiguration {@Beanpublic Docket createRestApi() {return new Docket(DocumentationType.SWAGGER_2).apiInfo(apiInfo()).select().apis(RequestHandlerSelectors.basePackage("cn.jacob")).paths(PathSelectors.any()).build();}private ApiInfo apiInfo() {return new ApiInfoBuilder().title("swagger-bootstrap-ui RESTful APIs").description("swagger-bootstrap-ui").termsOfServiceUrl("http://localhost:8083/").contact("m15870979735@qq.com").version("1.0").build();}}

主数据源配置类

@Configuration//扫描 Mapper 接口并容器管理@MapperScan(basePackages = {"cn.jacob.datasource.mapper.master"}, sqlSessionFactoryRef = "masterSqlSessionFactory")public class MasterDataSourceConfig {// 精确到 master 目录，以便跟其他数据源隔离static final String PACKAGE = "cn.jacob.datasource.mapper.master";static final String MAPPER_LOCATION = "classpath:mapper/**/*.xml";@Value("${master.datasource.url}")private String url;@Value("${master.datasource.username}")private String user;@Value("${master.datasource.password}")private String password;@Value("${master.datasource.driverClassName}")private String driverClass;@Primary@Bean(name = "masterDataSource")public DataSource masterDataSource() {DruidDataSource dataSource = new DruidDataSource();dataSource.setDriverClassName(driverClass);dataSource.setUrl(url);dataSource.setUsername(user);dataSource.setPassword(password);return dataSource;}@Bean(name = "masterTransactionManager")@Primarypublic DataSourceTransactionManager masterTransactionManager() {return new DataSourceTransactionManager(masterDataSource());}@Bean(name = "masterSqlSessionFactory")@Primarypublic SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource masterDataSource)throws Exception {final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();sessionFactory.setDataSource(masterDataSource);sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(MAPPER_LOCATION));return sessionFactory.getObject();}}

从数据源配置类

@Configuration//扫描 Mapper 接口并容器管理@MapperScan(basePackages = {"cn.jacob.datasource.mapper.cluster"}, sqlSessionFactoryRef = "clusterSqlSessionFactory")public class ClusterDataSourceConfig {// 精确到 cluster 目录，以便跟其他数据源隔离static final String PACKAGE = "cn.jacob.datasource.mapper.cluster";static final String MAPPER_LOCATION = "classpath:mapper/**/*.xml";@Value("${cluster.datasource.url}")private String url;@Value("${cluster.datasource.username}")private String user;@Value("${cluster.datasource.password}")private String password;@Value("${cluster.datasource.driverClassName}")private String driverClass;@Bean(name = "clusterDataSource")public DataSource clusterDataSource() {DruidDataSource dataSource = new DruidDataSource();dataSource.setDriverClassName(driverClass);dataSource.setUrl(url);dataSource.setUsername(user);dataSource.setPassword(password);return dataSource;}@Bean(name = "clusterTransactionManager")public DataSourceTransactionManager clusterTransactionManager() {return new DataSourceTransactionManager(clusterDataSource());}@Bean(name = "clusterSqlSessionFactory")public SqlSessionFactory clusterSqlSessionFactory(@Qualifier("clusterDataSource") DataSource clusterDataSource)throws Exception {final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();sessionFactory.setDataSource(clusterDataSource);sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(MAPPER_LOCATION));return sessionFactory.getObject();}}

1. 实体类，Dao层，Service层不再概括
2. 控制层
   便于区分创建两个控制器

@RestController@Slf4j@Api(value = "主数据源", tags = "主数据源")@RequestMapping("/username")@AllArgsConstructorpublic class UsernameController {private UsernameService usernameService;@GetMapping("/getList")@ApiOperation(value = "用户列表",notes = "用户列表")public List<Username> getList(){return usernameService.getList();}}
-----------------------------------------------------------------------------------------------------------------@RestController@Slf4j@Api(value = "从数据源", tags = "从数据源")@RequestMapping("/user")@AllArgsConstructorpublic class UserController {private UserService userService;@GetMapping("/getList")@ApiOperation(value = "用户列表",notes = "用户列表")public List<User> getList(){return userService.getList();}}