What is the bean, and the bean java Why make life difficult?
字面意义上:
java是咖啡,
bean是咖啡豆,
咖啡是由咖啡豆研磨出来的.
在javaee里,bean代表实体类用来与数据库表或者其他进行映射.通俗讲大概就这意思把.Java meets HTML - JavaBeans JSP chapter of
JavaBean, EJB, POJO.
PO (persistence object): When a persistent (e.g., cache or saved to the database);
VO (Object value): for display using a front end (e.g., placed into a JSP or parsing data transmitted to the front end of)
the DTO (Data Transfer Object) : an interface for each call returns, the data transmission (e.g., many interface call returns a message queue value or content);
Widely used for data exchange layered development.
EJB development in the enterprise, the need to scalable performance and transaction security mechanisms, this will ensure the smooth development of enterprise systems, rather than the development of one kind of scale to replace a software system. Then have improved the agreement, there have been Enterprise Bean. In EJB javabean basis we have referred to some of the requirements, of course, more complicated.
POJO man named Josh MacKenzie people think, EJB too complicated, each time with a completely unnecessary, so invented a POJO, POJO is common javabean, what is common, and is the corresponding EJB.
In short, the difference is that you first determine whether javabean conditions are met, then if we implement some of the requirements to meet the conditions that EJB EJB, otherwise POJO.