1. 问题输出：
APPLICATION FAILED TO START
***************************
Description:
A component required a bean of type 'javax.activation.DataSource' that could not be found.
Action:
Consider defining a bean of type 'javax.activation.DataSource' in your configuration.
2. 源码：
package boat.db.db;
import javax.activation.DataSource
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
@Component
public class DataSourceShow implements ApplicationContextAware {
@Autowired
ApplicationContext applicationContext = null;
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
DataSource dataSource = applicationContext.getBean(DataSource.class);
System.out.println("----------------------------------------------");
System.out.println(dataSource.getClass().getName());
System.out.println("----------------------------------------------");
}
}
解决：
起初以为是配置问题，增加了依赖项，并不起作用。
后仔细研究原例子发现，DataSource类不是 javax.activation.DataSource，而是import javax.sql.DataSource
改了后，正常运行
总结：
java有很多依赖项中有很多同名，但不同包的类型，所以使用时要注意