Essential Java Web Skills Every Backend Developer Must Master

1.底层

Beyond the basics of the Java language, understanding the JVM architecture, memory model, garbage collection algorithms, and classloader mechanisms is crucial. Monitoring and tuning the JVM, mastering multithreading, and grasping I/O models (BIO/NIO) and their Linux equivalents such as epoll are also essential.

2.Servlet

Servlets are server‑side Java programs that typically extend HttpServlet and implement init, doGet, doPost, and service. Their lifecycle starts with initialization, runs the service methods, and ends with destroy. Practical skills include deploying servlets in containers like Tomcat and managing compilation, packaging, and deployment without relying solely on IDE shortcuts.

3.框架

Spring

Spring is a powerful, often described as “lightweight,” Java framework that simplifies development through configuration‑driven programming, decoupling modules, and providing core services such as data access, remote communication, AOP, and container management.

Spring’s core concepts include:

IoC (Inversion of Control) : The container, rather than the class itself, manages object creation and configuration.

Dependency Injection : Dependencies are supplied by the container, promoting loose coupling.

AOP (Aspect‑Oriented Programming) : Separates cross‑cutting concerns from business logic, enabling reusable components.

Hibernate

Hibernate is a full‑featured ORM framework for object‑relational mapping, though many developers prefer MyBatis for its flexibility. Its workflow involves reading configuration, building a SessionFactory, opening a Session, managing transactions, performing persistence operations, and finally closing resources.

Understanding ORM means grasping how object models map to relational databases. Hibernate tracks entity states—transient, persistent, detached, and removed—and transitions among them.

Struts 2

Struts, one of the earliest MVC frameworks, simplifies Java web development by standardizing request handling, action execution, interceptor chains, value stacks, and OGNL expressions.

4.HTTP

Proficiency with HTTP is indispensable for web developers. Key topics include header formats, status codes, HTTPS implementation, B/S architecture, cookies and sessions, and RESTful API design.

5.设计模式

Rather than memorizing all 23 design patterns, focus on applying them in real projects, questioning their purpose, and developing the habit of recognizing when a pattern can improve code structure.

Beyond these topics, developers should adopt good practices such as using UML class and interaction diagrams before coding, and be prepared for deployment concerns like CDNs and load balancing.