What is Java Enterprise Edition

0 votes

I have been doing Java SE for some years now and moving on to Java EE. However I have some trouble understanding some aspects of Java EE.

  1. Is Java EE just a specification? What I mean is: Is EJB Java EE?

  2. Are EJB/Spring different implementations of Java EE?

I am sorry to ask but I have some difficulties to understand what Java EE is. Could someone explain what Java EE is? And EJB?

May 14, 2018 in Java by developer_1
• 3,350 points
850 views

1 answer to this question.

0 votes

Is Java EE just a specification? What I mean is: Is EJB Java EE?

Java EE is indeed an abstract specification. Anybody is open to develop and provide a working implementation of the specification. The concrete implementations are the so-called application servers, like WildFly, TomEE, GlassFish, Liberty, WebLogic, etc. There are also servlet containers which implement only the JSP/Servlet part of the huge Java EE API, such as Tomcat, Jetty, etc.

We, Java EE developers, should write code utilizing the specification (i.e. import only javax.*classes in our code instead of implementation specific classes such as org.jboss.wildfly.*, com.sun.glassfish.*, etc) and then we'll be able to run our code on any implementation (thus, on any application server). If you're familiar with JDBC, it's basically the same concept as how JDBC drivers work. See also a.o. In simplest terms, what is a factory?

The Java EE SDK download from Oracle.com contains basically the GlassFish server along a bunch of documentation and examples and optionally also the NetBeans IDE. You don't need it if you want a different server and/or IDE.

EJB is part of the Java EE specification. Look, it's in the Java EE API. Full-fledged Java EE application servers support it out the box, but simple JSP/Servlet containers don't.


Are EJB/Spring different implementations of Java EE?

No, as said, EJB is part of Java EE. Spring is a standalone framework which substitutes and improves many parts of Java EE. Spring doesn't necessarily require Java EE to run. A barebones servletcontainer like Tomcat is already sufficient. Simply put, Spring is a competitor of Java EE. E.g. "Spring" (standalone) competes EJB/JTA, Spring MVC competes JSF/JAX-RS, Spring DI/IoC/AOP competes CDI, Spring Security competes JAAS/JASPIC, etc.

Back during the old J2EE/EJB2 times, the EJB2 API was terrible to implement and maintain. Spring was then a much better alternative to EJB2. But since EJB3 (Java EE 5), the EJB API was much improved based on lessons learnt from Spring. Since CDI (Java EE 6), there's not really a reason to look at again another framework like Spring to make the developers more easy as to developing among others the service layer.

Only when you're using a barebones servletcontainer such as Tomcat and can't move on to a Java EE server, then Spring is more attractive as it's easier to install Spring on Tomcat. It isn't possible to install e.g. an EJB container om Tomcat without modifying the server itself, you would basically be reinventing TomEE.

answered May 14, 2018 by Rishabh
• 3,620 points

Related Questions In Java

+1 vote
3 answers

What is the syntax to declare and initialize an array in java?

You can use this method: String[] strs = ...READ MORE

answered Jul 25, 2018 in Java by samarth295
• 2,220 points
3,466 views
0 votes
2 answers

What is the difference between Set and List in java?

List is an ordered sequence of elements. ...READ MORE

answered Apr 26, 2018 in Java by Akrati
• 3,190 points
63,263 views
0 votes
2 answers

What is the use of @Override annotation in Java ? When do we use it ?

@Override annotation is used when we override ...READ MORE

answered Aug 14, 2019 in Java by Sirajul
• 59,230 points
3,410 views
0 votes
1 answer

What is the 'instanceof' operator used for in Java?

It's an operator that returns true if ...READ MORE

answered May 23, 2018 in Java by Rishabh
• 3,620 points
1,007 views
+5 votes
4 answers

How to execute a python file with few arguments in java?

You can use Java Runtime.exec() to run python script, ...READ MORE

answered Mar 27, 2018 in Java by DragonLord999
• 8,450 points

edited Nov 7, 2018 by Omkar 80,951 views
+1 vote
1 answer

How to handle drop downs using Selenium WebDriver in Java

First, find an XPath which will return ...READ MORE

answered Mar 27, 2018 in Selenium by nsv999
• 5,500 points
8,263 views
0 votes
1 answer

What are the differences between getText() and getAttribute() functions in Selenium WebDriver?

See, both are used to retrieve something ...READ MORE

answered Apr 5, 2018 in Selenium by nsv999
• 5,500 points
17,355 views
0 votes
1 answer

Selenium JARS(Java) missing from downloadable link

Nothing to worry about here. In the ...READ MORE

answered Apr 5, 2018 in Selenium by nsv999
• 5,500 points

edited Aug 4, 2023 by Khan Sarfaraz 4,769 views
0 votes
2 answers

What is the use of toString method in Java and how can I use it ?

Whenever you require to explore the constructor ...READ MORE

answered Aug 23, 2018 in Java by Daisy
• 8,140 points
4,053 views
0 votes
1 answer

What is the concept of Immutability for strings in Java ? Why are strings immutable ?

According to Effective Java, chapter 4, page 73, ...READ MORE

answered May 11, 2018 in Java by Rishabh
• 3,620 points
1,565 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP