EJB example for stateless and stateful beans difference
141232
When to use Stateful session bean over Stateless session bean?
59876
What is the difference between a JavaBean and a POJO?
36509
JPA EntityManager: Why use persist() over merge()?
31217
Relationship between EJB 3.0 and JPA?
79738
What is the difference between Strategy pattern and Dependency Injection?
80510
Implements vs extends: When to use? What's the difference?
60590
What's the difference between @Component, @Repository & @Service annotations in Spring?
89176
What's the difference between OpenJDK and Sun Java for the end user?
53845
Difference between Database.executeBatch and Queueable Apex
131102
Why does HttpServlet implement Serializable?
153434
Are there any guarantees in JLS about order of execution static initialization blocks?
65770
Which annotation should I use: @IdClass or @EmbeddedId
50960
What is the difference between JDK and JRE?
157894
What is the difference between Tomcat, JBoss and Glassfish?
65095
Why is spawning threads in Java EE container discouraged?
28124
What is the difference between currying and partial application?
29412
What is the difference between atomic / volatile / synchronized?