java exception 异常错误记录

//异常：Could not obtain transaction-synchronized Session for current thread
做定时器的时候用ApplicationContext的方法getBean("sessionFactory")获取sessionFactory;在获取getCurrentSession方法获取session,然后问题来了,直接报错: 
openSession每次打开都是新的Session,所以多次获取的Session实例是不同的，并且需要人为的调用close方法进行Session关闭。 
getCurrentSession是从当前上下文中获取Session并且会绑定到当前线程，第一次调用时会创建一个Session实例，如果该Session未关闭，后续多次获取的是同一个Session实例；事务提交或者回滚时会自动关闭Sesison,无需人工关闭。 
getCurrentSession方法的确和事务有关系所有要有事物。 而在spring的事务实现中需要判断当前线程中的事务是否同步,而没有事务的时候,那个判断是否同步的方法会因为get返回初始的null值而返回false,
最终导致throw一个Could not obtain transaction-synchronized Session for current thread的异常.

异常：java.lang.Long cannot be cast to java.lang.String

强制转换没有用括号把转换的包起来

String sum = (String)query.setCacheable(true).list().get(0);//错

String sum = (Long)(query.setCacheable(true).list().get(0))+"";//正确

错误：Incorrect string value: '\xD5\xC5\xC8\xFD' for column 'name'
是在添加方法时报错，原因是数据库或表的编码不对

//错误为查询的时候错误，原因为hibernate进行了一对多关联查询，而数据库中的有脏数据，导致关联查询失败

//jar包版本不同，引入驱动位置不同，配置写错
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'beetlSqlScannerConfigurer' defined in class path resource [com/ibeetl/starter/BeetlSqlConfig.class]: Unsatisfied dependency expressed through method 'getBeetlSqlScannerConfigurer' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'sqlManagerFactoryBean' defined in class path resource [com/ibeetl/starter/BeetlSqlConfig.class]: Unsatisfied dependency expressed through method 'getSqlManagerFactoryBean' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [com/bw/core/conf/DataSourceConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'datasource' threw exception; nested exception is java.lang.RuntimeException: Failed to load driver class com.mysql.cj.jdbc.Driver in either of HikariConfig class loader or Thread context classloader