52 docs tagged with "java"

Hide complexity behind a clean contract — when to use abstract classes vs. interfaces, default methods, and the design forces that govern the choice.

Hands-on code examples and step-by-step walkthroughs for Abstraction in Java.

Built-in annotations, custom annotations, meta-annotations, annotation processing.

Single and multi-dimensional arrays, creation, initialization, traversal, and the Arrays utility class.

Quick-reference pages for common Java APIs, collections, concurrency, and streams.

Understand Java classes as blueprints and objects as runtime instances — fields, methods, constructors, and the `this` keyword.

Hands-on code examples and step-by-step walkthroughs for Classes & Objects in Java.

AWS/GCP/Azure, cloud-native patterns, managed services.

Collections hierarchy, List, Set, Map, iterators, Comparable vs Comparator, Collections utility class, immutability.

if/else, switch expressions, for, while, do-while, break, continue — directing program execution in Java.

Core classes — Object, String, Math, wrapper classes.

Language basics — variables, data types, operators, control flow, type conversion.

Consolidated interview Q&A for Core Java covering beginner through advanced topics — variables, types, operators, control flow, arrays, strings, methods, and packages.

Quick-reference summary of Core Java concepts, APIs, and interview questions for rapid revision.

Common data structures, algorithms, complexity analysis, Java implementations.

SQL, NoSQL, connection pooling, schema migration (Flyway/Liquibase).

Common GoF design patterns expressed with Java examples.

CI/CD pipelines, monitoring, observability, Spring Boot Actuator.

Hide internal state behind a controlled interface — access modifiers, getters/setters, and the art of designing immutable classes.

Hands-on code examples and step-by-step walkthroughs for Encapsulation in Java.

Exception hierarchy, checked vs unchecked exceptions, try/catch/finally, try-with-resources, custom exceptions.

Lambdas, functional interfaces, Streams API, method references, Optional.

File handling, streams, buffers, channels, serialization, and NIO APIs.

Extend classes with `extends`, override behavior with `@Override`, use `super` for parent delegation, and learn when inheritance causes more harm than good.

Hands-on code examples and step-by-step walkthroughs for Inheritance in Java.

Consolidated domain-specific Q&A for Java backend engineering interviews.

Core Java language, standard library, JVM, and runtime concepts organized as dedicated subdomains.

Language and platform changes across Java versions — Java 8, 11, 17, 21.

Java 9+ module system (JPMS), module-info.java, strong encapsulation, requires/exports.

Primitives vs objects, autoboxing/unboxing, generics, type inference, wildcards, type erasure, bounded type parameters.

Class loading, memory management, garbage collection, JIT compilation.

Kafka, RabbitMQ, async patterns, event-driven architecture.

Method signatures, overloading, varargs, pass-by-value semantics, and recursion in Java.

Threads, lifecycle, synchronization, concurrency utilities, volatile, virtual threads.

OOP principles — classes, objects, inheritance, polymorphism, encapsulation, abstraction, interfaces, records, sealed classes.

Consolidated interview Q&A for Java OOP covering beginner through advanced topics — classes, encapsulation, inheritance, polymorphism, abstraction, records, and sealed classes.

Quick-reference summary of Java OOP concepts — classes, encapsulation, inheritance, polymorphism, abstraction, records, and sealed classes.

Arithmetic, relational, logical, bitwise, ternary, and instanceof operators — how Java evaluates expressions.

Quick-reference summaries for every domain — designed for rapid revision before interviews.

Package structure, the import statement, the classpath, access modifiers, and how Java locates classes.

Compile-time (overloading) vs. runtime (overriding) dispatch — how Java decides which method to call and why this is the foundation of flexible design.

Hands-on code examples and step-by-step walkthroughs for Polymorphism in Java.

Hands-on code examples and step-by-step walkthroughs for Records (Java 16+) in Java.

Java's concise immutable data carrier — understand what records generate automatically, compact constructors, and when records replace traditional value classes.

Hands-on code examples and step-by-step walkthroughs for Sealed Classes (Java 17+) in Java.

Restrict which classes can extend or implement a type — enabling exhaustive pattern matching and modeling closed, well-known type hierarchies safely.

String immutability, the string pool, StringBuilder, and the most useful String APIs in Java.

High-level architecture, microservices, distributed systems, SOLID principles.

Unit testing, integration testing, Testcontainers, Mockito, JUnit 5.

How Java converts values between types — widening, narrowing, implicit promotion, and explicit casting.

The 8 primitive types, reference types, literals, constants, and the final keyword in Java.

Git internals, branching strategies, workflows, and collaboration best practices.