有一个这样子的需求，线上正在跑的业务，由于业务发展需要，需重新开发一套新系统，等新系统开发完成后，需要无缝对接切换，当初具体设计见草图。
添加依赖#
<!--lombok--> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.16</version> <!--scope=provided，说明它是在编译阶段生效，不需要打入包中，Lombok在编译期将带Lombok注解的Java文件正确编译为完整的Class文件--> <scope>provided</scope> </dependency> <!--mysql--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <!--mybatis plus和spring boot整合--> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-boot-starter</artifactId> <version>3.4.0</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.1.10</version> </dependency>application.properties#
server.port=9999 spring.datasource.master.driver-class-name=com.mysql.cj.jdbc.Driver spring.datasource.master.url=jdbc:mysql://127.0.0.1/test?useUnicode=true&characterEncoding=utf-8&useSSL=false spring.datasource.master.username=root spring.datasource.master.password=root spring.datasource.slave.driver-class-name=com.mysql.cj.jdbc.Driver spring.datasource.slave.jdbc-url=jdbc:mysql://127.0.0.1/test2?useUnicode=true&characterEncoding=utf-8&useSSL=false spring.datasource.slave.username=root spring.datasource.slave.password=root2种方式创建DataSource#
Master配置，使用druid连接池#
import com.alibaba.druid.pool.DruidDataSource; import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean; import org.apache.ibatis.session.SqlSessionFactory; import org.mybatis.spring.annotation.MapperScan; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.Primary; import org.springframework.core.env.Environment; import javax.sql.DataSource; /** * @Author：chenyanbin */ @Configuration @MapperScan(basePackages = "com.example.demo.mapper", sqlSessionFactoryRef = "masterSqlSessionFactory") public class MasterDataSourceConfig { @Autowired private Environment env; @Primary @Bean(name = "masterDataSource") // @ConfigurationProperties("spring.datasource.master") public DataSource masterDataSource() { // return DataSourceBuilder.create().build(); DruidDataSource dataSource = new DruidDataSource(); dataSource.setUrl(env.getProperty("spring.datasource.master.url")); dataSource.setUsername(env.getProperty("spring.datasource.master.username")); dataSource.setPassword(env.getProperty("spring.datasource.master.password")); dataSource.setDriverClassName(env.getProperty("spring.datasource.master.driver-class-name")); //配置初始化大小、最小、最大 dataSource.setMinIdle(10); //配置初始化大小、最小、最大 dataSource.setMaxActive(200); //配置初始化大小、最小、最大 dataSource.setInitialSize(10); //配置获取连接等待超时的时间 dataSource.setMaxWait(60000); //配置一个连接在池中最小生存的时间,单位是毫秒 dataSource.setMinEvictableIdleTimeMillis(300000); //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 dataSource.setTimeBetweenEvictionRunsMillis(60000); //默认的testWhileIdle=true,testOnBorrow=false,testOnReturn=false dataSource.setValidationQuery("SELECT 1"); //申请连接时执行validationQuery检测连接是否有效 dataSource.setTestOnBorrow(false); //建议配置为true，不影响性能，并且保证安全性。 dataSource.setTestWhileIdle(true); //是否缓存preparedStatement，也就是PSCache dataSource.setPoolPreparedStatements(false); return dataSource; } @Bean(name = "masterSqlSessionFactory") public SqlSessionFactory sqlSessionFactory(@Qualifier("masterDataSource") DataSource dataSource) throws Exception { MybatisSqlSessionFactoryBean sessionFactoryBean = new MybatisSqlSessionFactoryBean(); sessionFactoryBean.setDataSource(dataSource); return sessionFactoryBean.getObject(); } }Slave配置#
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean; import org.apache.ibatis.session.SqlSessionFactory; import org.mybatis.spring.annotation.MapperScan; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.boot.jdbc.DataSourceBuilder; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import javax.sql.DataSource; /** * @Author：chenyanbin */ @Configuration @MapperScan(basePackages = "com.example.demo.mapper2",sqlSessionFactoryRef = "slaveSqlSessionFactory") public class SlaveDataSourceConfig { @Bean(name = "slaveDataSource") @ConfigurationProperties("spring.datasource.slave") public DataSource slaveDataSource(){ return DataSourceBuilder.create().build(); } @Bean(name = "slaveSqlSessionFactory") public SqlSessionFactory sqlSessionFactory(@Qualifier("slaveDataSource") DataSource dataSource) throws Exception { MybatisSqlSessionFactoryBean sessionFactoryBean = new MybatisSqlSessionFactoryBean(); sessionFactoryBean.setDataSource(dataSource); return sessionFactoryBean.getObject(); } }注意#
master和slave扫描不同的mapper包路径！！！！！！
如果需要指定.xml文件，需这样配置！！！
@Bean(name = "masterSqlSessionFactory") public SqlSessionFactory sqlSessionFactory(@Qualifier("masterDataSource") DataSource dataSource) throws Exception { MybatisSqlSessionFactoryBean sessionFactoryBean = new MybatisSqlSessionFactoryBean(); sessionFactoryBean.setDataSource(dataSource); sessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver() .getResources("classpath:mapper/**/*.xml")); return sessionFactoryBean.getObject(); }启动类#
@SpringBootApplication( exclude = {DataSourceAutoConfiguration.class, MybatisPlusAutoConfiguration.class} )启动类上排查，自动装配，使用我们自定义的多数据源！！！
演示#
多个数据源，同时也是支持事务的
