主数据源：注意一定要指明primary

@Configuration
// 扫描 Mapper 接口并容器管理
@MapperScan(basePackages = SearchDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "searchSqlSessionFactory")
public class SearchDataSourceConfig {
    // 精确到 master 目录，以便跟其他数据源隔离
    static final String PACKAGE = "com.ysten.viper.search.manager.repository.mapper";
    static final String MAPPER_LOCATION = "classpath*:mapper/*.xml";

    @Value("${search.datasource.url}")
    private String url;

    @Value("${search.datasource.username}")
    private String user;

    @Value("${search.datasource.password}")
    private String password;

    @Value("${search.datasource.driverClassName}")
    private String driverClass;

    @Bean(name = "searchDataSource")
    @Primary
    public DataSource searchDataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driverClass);
        dataSource.setUrl(url);
        dataSource.setUsername(user);
        dataSource.setPassword(password);
        System.out.println(dataSource);
        return dataSource;
    }

    @Bean(name = "searchTransactionManager")
    @Primary
    public DataSourceTransactionManager searchTransactionManager() {
        return new DataSourceTransactionManager(searchDataSource());
    }

    @Bean(name = "searchSqlSessionFactory")
    @Primary
    public SqlSessionFactory searchSqlSessionFactory(@Qualifier("searchDataSource") DataSource searchDataSource)
            throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(searchDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources(SearchDataSourceConfig.MAPPER_LOCATION));
        return sessionFactory.getObject();
    }
}

另一个数据源

@Configuration
// 扫描 Mapper 接口并容器管理
@MapperScan(basePackages = AnalysisDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "analysisSqlSessionFactory")
public class AnalysisDataSourceConfig {
    // 精确到 master 目录，以便跟其他数据源隔离
    static final String PACKAGE = "com.ysten.viper.search.manager.analysis.repository.mapper";
    static final String MAPPER_LOCATION = "classpath*:mapper/*.xml";

    @Value("${analysis.datasource.url}")
    private String url;

    @Value("${analysis.datasource.username}")
    private String user;

    @Value("${analysis.datasource.password}")
    private String password;

    @Value("${analysis.datasource.driverClassName}")
    private String driverClass;

    @Bean(name = "analysisDataSource")
    public DataSource analysisDataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driverClass);
        dataSource.setUrl(url);
        dataSource.setUsername(user);
        dataSource.setPassword(password);
        System.out.println(dataSource);
        return dataSource;
    }

    @Bean(name = "analysisTransactionManager")
    public DataSourceTransactionManager analysisTransactionManager() {
        return new DataSourceTransactionManager(analysisDataSource());
    }

    @Bean(name = "analysisSqlSessionFactory")
    public SqlSessionFactory analysisSqlSessionFactory(@Qualifier("analysisDataSource") DataSource analysisDataSource)
            throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(analysisDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources(AnalysisDataSourceConfig.MAPPER_LOCATION));
        return sessionFactory.getObject();
    }
}

application.properties配置

#mysql 多数据源
search.datasource.url=jdbc:mysql://192.168.50.21:3306/search?useUnicode=true&characterEncoding=utf8
search.datasource.username=root
search.datasource.password=ysten123
search.datasource.driverClassName=com.mysql.jdbc.Driver

analysis.datasource.url=jdbc:mysql://192.168.50.21:3306/search_phrase?useUnicode=true&characterEncoding=utf8
analysis.datasource.username=root
analysis.datasource.password=ysten123
analysis.datasource.driverClassName=com.mysql.jdbc.Driver

user.datasource.url=jdbc:mysql://192.168.50.21:3306/springbootdb?useUnicode=true&characterEncoding=utf8
user.datasource.username=root
user.datasource.password=ysten123
user.datasource.driverClassName=com.mysql.jdbc.Driver

city.datasource.url=jdbc:mysql://192.168.50.21:3306/springbootdb_cluster?useUnicode=true&characterEncoding=utf8
city.datasource.username=root
city.datasource.password=ysten123
city.datasource.driverClassName=com.mysql.jdbc.Driver