Essential Java Knowledge for Enterprise Development and Interview Preparation

Java is used for enterprise projects. To work on enterprise‑level development you must master basic project steps, strong object‑oriented analysis and design, and architecture‑centric development methods.

Core Java SE topics include syntax, data types, operators, exception handling, collections, common classes, reflection, I/O streams, and multithreading.

Servlets and JSP cover HttpServlet, doGet/doPost, request/response handling, filters, web.xml configuration, Tomcat, forwarding, redirecting, HTTP statelessness, cookies, JSP scopes, and JSTL tags such as <c:out …/> and <c:forEach …>.

HTML and JavaScript basics are required to understand common web tags and how to embed and use JavaScript in web pages.

SSH Frameworks (Struts2, Spring, Hibernate) are discussed, emphasizing their role in solving common Java EE problems and providing interview questions to assess deep understanding:

Struts2

Why is an Action object created for each request?

What problem does the refreshModelBeforeResult setting solve in ModelDriven interceptor?

Why does StrutsPrepareAndExecuteFilter filter all requests in web.xml?

Explain the ValueStack concept.

How does Struts2 implement the MVC pattern?

Spring

Why use Spring?

Discuss IoC/DI.

What is declarative transaction management and how does Spring implement it?

When integrating Spring with Hibernate, why mark read‑only methods that only perform queries?

Hibernate

Explain your understanding of ORM mapping.

Why do some claim Hibernate is unsuitable for large projects?

Why must an entity define a database identifier?

Why should entity classes implement hashCode and equals?

Discuss the relationship between the entity identifier and the primary key.

Explain the link between association mapping and foreign keys.

Does session.save() always issue an INSERT? Explain.

Does session.update() always issue an UPDATE? Explain.

Describe lazy, lazy="extra", inverse, fetch, fetch="join", fetch="subselect", batch-size.

Does setting lazy="true" guarantee lazy loading?

Discuss the N+1 problem and best practices to avoid it.

The article stresses that real project experience, modeling ability, requirement analysis, design, implementation, testing, and problem‑solving (performance, changes, etc.) are essential for turning requirements into valuable solutions and advancing a developer’s career.