this month
Java
The most encouraging thing is the most encouraging thing.
EJB 3.0
Size has been fixed,
2004
year
5
month
6
day,
EJB
Chief designer
Linda Demichiel
In noisy
TSS
Annual meeting (
http://www.theserverside.com/symposium/
)
EJB 3.0
Major change.
EJB 3.0 Overall goal is easy to develop. Since EJB 1.0, I have suffered a lot of people's attacks. Later, I finally launched EJB 2.0, and I corrected a lot of problems, especially performance issues, but EJB is difficult to learn and use it. It has become EJB or J2EE develops growing fatal dangers.
At this critical moment, the EJB Standards Committee has been achieved by all aspects, and specially learned the idea of lightweight programming models in the open source field, and launched new ideas for EJB3.0, EJB 3.0 is mainly the following Features:
First, it is easy to develop, the current EJB is weight for programmers because the programmer builds an EJB requires many steps: Create a few interface files and a configuration file.
In EJB3.0, it will be very simple in establishing a session bean, as follows:
@Session public class helloworldbean {
Public void syhello (string s) {
System.out.println ("Hello:" S);
}
}
Second, introducing the Dependency Injection mode (a new IOC mode, also AOP foundation mode) replaces JNDI's Lookup, which makes it easier to get the EJB container external test program.
Finally, it simplifies the persistent layer entity bean cmp, and the entity bean cmp in EJB is due to weight and complex by many programmers, and therefore, the open source project hibernate has become a new darling of many programmers, EJB 3.0 sucks Hibernate and Toplink light The amount is characterized by simplifying CMP, making the CMP of EJB 3.0 sufficient to form a competition in the ORM products such as persistence technology and Hibernate.
GAVIN KING launched the selection of J2EE persistence technology through Hibernate, Gavin King recently launched JDO in his blog (http://blosxom.cgi/cgi-bin/blosxom.cgi/) Criticism, he believes that there is a lot of shortcomings in JDO, which needs to be rewritten, but the EJB 3.0 entity Entity is closer to the ORM solution. At the same time, both main J2EE application server manufacturers (BEA, IBM and Oracle) rejected JDO 2.0. These vendors believe that: EJB3.0 should achieve a simpler persistence layer model, which is not necessary to use another set of persistence models for J2EE. (Therefore, CMP will continue to be a persistent technology of EJB 3.0, and the entity bean entity bean will continue to be retained)
GAVIN KING is currently effective in JBoss organization, engaged in JBoss CMP engine optimization, from one aspect, he also contributed to the good talents in persistence layer to achieve the CMP standard implementation. Although Hibernate did not become EJB 3.0 persistent layer standard layer, Gavin King himself is undoubtedly the most worthy of respect and worship.
About EJB 3.0 warm discussion is currently continuing, English discussion shows TSS special website: http://www.theserverside.com/news/thread.tss? Thread_id = 25779, Chinese discussion visible: http://www.jdon .com / jive / article.jsp? forum = 16 & threeRead = 13853. Before the EJB 3.0 prototype, the Java community prevalent various ideas and remarks of EJBs, including various reasons, one of the main reasons, EJB products have been synonymous with nobles, and the main members of the EJB Standards Committee are the world In addition to the largest software vendors outside Microsoft, the spearhead of open source communities directly points to these merchants. Even EJB open source project JBOSS has not been spared, and some extreme pink is ridiculed as 傀儡.
Rod Johnson is a representative of anti-EJB, and he created a famous open source project Spring. This AOP-based open source framework final goal is to replace EJB. Rod Johnson has set a lecture specifically in this TSS annual meeting: J2EE WITHOUT EJBS, current Tomca Spring Hibernate has gradually become an architecture option for J2EE developer preferences.
In fact, the current ejb is difficult to use is to promote the current main reason for the current programmer. Maybe the EJB Bronet Committee has noted this problem, so I published the EJB 3.0 prototype on this annual meeting, this finally let EJB The supporter is very comfortable, and they also published their own opinions, see the following website: http://radio.weblogs.com/0135826/2004/05/09.html#a27.
Therefore, this TSS annual meeting is also a thrilling, and all the trends in the Java community are concentrated here. Of course, these people who like to be quiet can be too noisy, especially those who wait and see at the Java door. Feeling concern, is there a problem with Java technology, why no one can rest assured to choose technology? Can I wait until the Java community debate, then enter the Java world?
In fact, this is a misunderstanding, there is no perfect technology, only the technique of unique technology, arguing representative, and the noise of the Java community reflects the opening and freedom of the Java world, in the Java community, developers can really do their own , You can choose the technology suitable for yourself according to the actual situation, is you willing to give up this autonomy option?
