Win a copy of Re-engineering Legacy Software this week in the Refactoring forum
or Docker in Action in the Cloud/Virtualization forum!
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

EJB - Fresher Question

 
Guru dhaasan
Ranch Hand
Posts: 126
Java Ubuntu VI Editor
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi,

I am new to EJB and I am going thro "Enterprise Java Beans 3.1" (O'Reilly) book. In that it has been mentioned different terminologies like

  • EJB
    Bean
    Remote
    Local
    RemoteHome
    LocalHome
    RemoteBusiness
    LocalBusiness

  • Can anybody explain what are these terminologies mean in a java-layman tone....
    Also if you can give some details about how exactly EJB fits in an Enterprise appln. with an real-life-example-app would be great

    Thanks in advance
     
    Jeanne Boyarsky
    author & internet detective
    Marshal
    Posts: 34095
    337
    Eclipse IDE Java VI Editor
    • Mark post as helpful
    • send pies
    • Quote
    • Report post to moderator
    How far did you get in the book? A lot is explained there. Maybe if you tried to define the terms in your own words and we can confirm/clarify your understanding.
     
    Guru dhaasan
    Ranch Hand
    Posts: 126
    Java Ubuntu VI Editor
    • Mark post as helpful
    • send pies
    • Quote
    • Report post to moderator
    Thanks Jeanne for your response.

    I just started on the book and I am at the end of Part I.

    To my understanding, from the client perspective (for ex., from a servlet)
    we can call an EJB. For this we will get an interface which can be used in the client and the corresponding implementation class will be there to serve the purpose (of the interface)

    What I dont understand is what these Local/Remote jargons are doing

    Please consider myself as a novice in the business comp. dev. field

    Awaiting your response
     
    Jeanne Boyarsky
    author & internet detective
    Marshal
    Posts: 34095
    337
    Eclipse IDE Java VI Editor
    • Likes 1
    • Mark post as helpful
    • send pies
    • Quote
    • Report post to moderator
    Ok. You have the basic idea. Way back when, there were only remote interfaces. You got a remote home interface and used it to look up the bean's remote interface. The problem was that most people were deploying the servlet and "remote" ejb on the same server. This resulted in an unneeded performance overhead. As a result, they introduced local interfaces to cut that down and make ejb more efficient. Now, you have a choice between remote and local based on your actual needs.
     
    Guru dhaasan
    Ranch Hand
    Posts: 126
    Java Ubuntu VI Editor
    • Mark post as helpful
    • send pies
    • Quote
    • Report post to moderator
    Thanks Jeanne...
    Got the idea
     
    • Post Reply
    • Bookmark Topic Watch Topic
    • New Topic