转载

springboot多数据源

项目结构图

搭建步骤

pom

 1<dependency>
 2            <groupId>org.springframework.boot</groupId>
 3            <artifactId>spring-boot-starter-web</artifactId>
 4        </dependency>
 5        <dependency>
 6            <groupId>org.mybatis.spring.boot</groupId>
 7            <artifactId>mybatis-spring-boot-starter</artifactId>
 8            <version>2.1.1</version>
 9        </dependency>
10
11        <dependency>
12            <groupId>org.projectlombok</groupId>
13            <artifactId>lombok</artifactId>
14        </dependency>
15        <dependency>
16            <groupId>mysql</groupId>
17            <artifactId>mysql-connector-java</artifactId>
18            <scope>runtime</scope>
19        </dependency>
复制代码

application.yml

 1server:
 2  port: 8080
 3spring:
 4  datasource:
 5    db1:
 6      username: root
 7      password: 123456
 8      driver-class-name: com.mysql.cj.jdbc.Driver
 9      jdbc-url: jdbc:mysql://localhost:3306/db_demo_sys?serverTimezone=Asia/Shanghai
10    db2:
11      username: root
12      password: 123456
13      driver-class-name: com.mysql.cj.jdbc.Driver
14      jdbc-url: jdbc:mysql://localhost:3306/db_demo_per?serverTimezone=Asia/Shanghai
复制代码

上面可以看到，我访问的不同数据库，数据库语句啥的就不贴了。

数据源配置类

这里我用了2个数据源，建立2个配置类。

DBConfig1.java

 1package com.lytw13.demo.config;
 2
 3import org.apache.ibatis.session.SqlSessionFactory;
 4import org.mybatis.spring.SqlSessionFactoryBean;
 5import org.mybatis.spring.SqlSessionTemplate;
 6import org.mybatis.spring.annotation.MapperScan;
 7import org.springframework.beans.factory.annotation.Qualifier;
 8import org.springframework.boot.context.properties.ConfigurationProperties;
 9import org.springframework.boot.jdbc.DataSourceBuilder;
10import org.springframework.context.annotation.Bean;
11import org.springframework.context.annotation.Configuration;
12import org.springframework.context.annotation.Primary;
13import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
14
15import javax.sql.DataSource;
16
17@Configuration
18@MapperScan(basePackages = "com.lytw13.demo.mapper.db1", sqlSessionFactoryRef = "sqlSessionFactory1")
19public class DBConfig1 {
20
21  @Bean
22  @Primary
23  @ConfigurationProperties(prefix = "spring.datasource.db1")
24  public DataSource dataSource1() {
25      return DataSourceBuilder.create().build();
26  }
27  @Bean
28  @Primary
29  public SqlSessionFactory sqlSessionFactory1(@Qualifier("dataSource1") DataSource dataSource) throws Exception {
30      SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
31      sqlSessionFactoryBean.setDataSource(dataSource);
32      sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/db1/*.xml"));
33      return sqlSessionFactoryBean.getObject();
34  }
35}
复制代码

DBConfig2.java

 1package com.lytw13.demo.config;
 2
 3import org.apache.ibatis.session.SqlSessionFactory;
 4import org.mybatis.spring.SqlSessionFactoryBean;
 5import org.mybatis.spring.annotation.MapperScan;
 6import org.springframework.beans.factory.annotation.Qualifier;
 7import org.springframework.boot.context.properties.ConfigurationProperties;
 8import org.springframework.boot.jdbc.DataSourceBuilder;
 9import org.springframework.context.annotation.Bean;
10import org.springframework.context.annotation.Configuration;
11import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
12
13import javax.sql.DataSource;
14
15@Configuration
16@MapperScan(basePackages = "com.lytw13.demo.mapper.db2", sqlSessionFactoryRef = "sqlSessionFactory2")
17public class DBConfig2 {
18
19  @Bean
20  @ConfigurationProperties(prefix = "spring.datasource.db2")
21  public DataSource dataSource2() {
22      return DataSourceBuilder.create().build();
23  }
24  @Bean
25  public SqlSessionFactory sqlSessionFactory2(@Qualifier("dataSource2")DataSource dataSource) throws Exception {
26      SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
27      sqlSessionFactoryBean.setDataSource(dataSource);
28      sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/db2/*.xml"));
29      return sqlSessionFactoryBean.getObject();
30  }
31}
复制代码

上面两个没有什么区别，就是在配置的时候指定各自的扫描位置， 主数据源需要添加上@Primary注解 ，标识这是一个主数据源，其他没什么了。

下面的controller，service啥的就不贴了，应该都知道咋回事。

测试

分别访问 http://localhost:8080/teacher/get/1 和 http://localhost:8080/user/get/1，查看是否能取到值。

可能会遇到的错误

Parameter 0 of method sqlSessionTemplate in org.mybatis.spring.boot.autoconfigure.MybatisAutoConfiguration required a single bean, but 2 were found

 1Description:
 2
 3Parameter 0 of method sqlSessionTemplate in org.mybatis.spring.boot.autoconfigure.MybatisAutoConfiguration required a single bean, but 2 were found:
 4    - sqlSessionFactory1: defined by method 'sqlSessionFactory1' in class path resource [com/lytw13/demo/config/DBConfig1.class]
 5    - sqlSessionFactory2: defined by method 'sqlSessionFactory2' in class path resource [com/lytw13/demo/config/DBConfig2.class]
 6
 7
 8Action:
 9
10Consider marking one of the beans as @Primary, updating the consumer to accept multiple beans, or using @Qualifier to identify the bean that should be consumed
复制代码

解决方法：

查看在设置sqlsessionfactory的时候有没有使用@Qualifier注解指定datasource;
查看是否忘记主数据源是否忘记添加@Primary注解。

我这里就是忘记添加注解了，疏忽了。

Cause: java.lang.IllegalArgumentException: jdbcUrl is required with driverClassName.

1There was an unexpected error (type=Internal Server Error, status=500).
2nested exception is org.apache.ibatis.exceptions.PersistenceException: ### Error querying database. Cause: java.lang.IllegalArgumentException: jdbcUrl is required with driverClassName. ### The error may exist in file [E:/lytw13/demo_multidatasource/target/classes/mapper/db1/UserMapper.xml] ### The error may involve com.lytw13.demo.mapper.db1.UserMapper.selectByPrimaryKey ### The error occurred while executing a query ### Cause: java.lang.IllegalArgumentException: jdbcUrl is required with driverClassName.
复制代码