springboot项目，之前有mysql数据源，现在又新增了clickhouse数据源，于是

新增了一个clickhouseDatasource的配置bean，如下：

	@Beanpublic DataSource dataSource() throws PropertyVetoException {HikariConfig config = new HikariConfig();String jdbcUrl = ConfigCentre.getString(ConfigConst.EC_MYSQL_URL);if (StringUtils.isBlank(jdbcUrl)) {return null;}String userName = ConfigCentre.getString(ConfigConst.EC_MYSQL_USERNAME);String password = ConfigCentre.getString(ConfigConst.EC_MYSQL_PASSWORD);config.setJdbcUrl(jdbcUrl);config.setUsername(userName);config.setPassword(password);config.addDataSourceProperty("cachePrepStmts", "true");config.addDataSourceProperty("prepStmtCacheSize", "250");config.addDataSourceProperty("prepStmtCacheSqlLimit", "2048");HikariDataSource dataSource = new HikariDataSource(config);return dataSource;}@Beanpublic ClickHouseDataSource getClickHouseDataSource(){ClickHouseProperties properties = new ClickHouseProperties();properties.setDataTransferTimeout(5*60*1000);properties.setMaxExecutionTime(5*60*1000);properties.setUseTimeZone("UTC");properties.setUseServerTimeZone(false);ClickHouseDataSource clickHouseDataSource = new ClickHouseDataSource(CLICKHOUSEFORADRESPONSEURL, properties);return clickHouseDataSource;}

用这个bean的时候：

	@@Autowiredprivate ClickHouseDataSource clickHouseDataSource;

但是这样就报错了，如下：

nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'getClickHouseDataSource' defined in com.yeahmobi.dsp.DBBeans: 
Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSourceInitializer': 
Invocation of init method failed; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: 
No qualifying bean of type [javax.sql.DataSource] is defined: expected single matching bean but found 2: dataSource,getClickHouseDataSource

主要提示在DataSource … but but found 2:dataSource,getClickHouseDataSource

最后发现，是因为Spring认为这两个bean是同一类型的bean

看ClickHouseDataSource这个类的源码：

public class ClickHouseDataSource implements DataSource{...
}

看上面那个DataSource返回的真正实体类：HikariDataSource源码（注：Hikari连接池，号称是java平台最快的，替换druid）

public class HikariDataSource extends HikariConfig implements DataSource, Closeable {...
}

发现ClickHouseDataSource也是实现了DataSource类，而上面那个HikariDataSource也是实现了HikariDataSource ，所以这也算bean重复了。所以得在Bean定义的时候分别申明。
但由于之前这个DataSource，已经有很多地方在用了，改的时候不方便，所以就采用默认是HikariDataSource，用ClickHouseDataSource的时候，再手动申明的策略。

解决：

原来DataSource的Bean定义上，再加注解@Primary，如下：

@Bean@Primarypublic DataSource dataSource() throws PropertyVetoException {......return dataSource;}

用到ClickhouseDataSource Bean的地方，用@Resource注入，指明name是哪个方法名。

	@Resource(name = "getClickHouseDataSource")private ClickHouseDataSource clickHouseDataSource;

再次启动，ok