“the key benefit of DI is loose coupling. If an object only knows about its dependencies by their interface then the dependency can be swapped out with a different implementation without the depending object knowing the difference” Spring in action
Posts tagged java
JPA create sql error
在创建entity的时候要注意entity的名字是否是对应的db的保留字 现在的开发中用到了lock这个entity，在persistence的时候出现错误： You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘Lock (lockOwner_UU ID, version_UUID, UUID) values (‘ff808181211ae76901211ae76c2c0′ at line 1 因为lock是mysql的保留字。 mysql的所有保留字可以在下面的网页里查到 http://dev.mysql.com/doc/refman/5.1/en/reserved-words.html
InputStream
还真是stream，读掉，就没了。真正的流走了。 读一个文件到inputstream， 用jaxb转换为element后，stream里就没有东西了，再想把他转换为string，得到的就是空的。
java.lang.IncompatibleClassChangeError: Implementing class
Every time I have seen this kind of error it was because I changed a class that other classes depended on, but did not recompile the dependent classes. 开发web程序的时候要deploy，可能会导致server段的class是旧的
