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Java

Java for people starting out: classes, collections, exceptions and the object-oriented ideas the language is built around.

17 guides

Java

Java and the Spring Framework

What Spring actually does: dependency injection, beans and configuration, plus Spring Boot, and how a request travels through a Spring application.

5 min read

Java

Java GUI Programming

Building desktop interfaces in Java: Swing for simplicity, JavaFX for modern applications, layout managers, events, and the threading rule you must not…

4 min read

Java

Java Database Connectivity (JDBC)

Connecting to a database from Java with JDBC: prepared statements, try-with-resources, transactions, connection pooling, and when to use JPA instead.

4 min read

Java

Java Collections Framework

Lists, sets, maps and queues in Java: which to choose, how they differ in speed, and the mistakes that cause ConcurrentModificationException and…

4 min read

Java

Java Web Development

How a Java web application is put together: servlets, Spring Boot, REST endpoints, templates, database access and what to configure before deploying.

4 min read

Java

Java Security

The security work that matters in Java applications: SQL injection, deserialization, dependency vulnerabilities, password hashing, XML parsing and secrets handling.

5 min read

Java

Java Performance Optimization

Where Java applications actually spend their time, how to profile before you guess, and the fixes that matter: collections, strings, streams and…

5 min read

Java

Java Not Working in VS Code

No IntelliSense, "cannot find symbol" on everything, or the run button does nothing? VS Code needs a JDK it can find and…

4 min read

Java

What’s New in Java 25 LTS

Java 25 is the current long-term release. Flexible constructors, compact source files, module imports and scoped values are final; here is what…

4 min read

Java

Java Input and Output (I/O)

Reading and writing files in Java: the modern Files and Path API, buffered streams for large files, reading keyboard input, and try-with-resources.

4 min read

Related topics

Where to go next

Programming Basics The ideas every language shares — variables, loops, functions and how a program actually runs. 17 guides Python Plain-English Python guides, from your first line of code to small programs that do real work. 72 guides JavaScript How JavaScript works in the browser, explained with short examples you can paste and run. 32 guides

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