iluwatar/java-design-patterns

iluwatar/java-design-patterns is a large educational repository that collects working examples of well-known software design patterns, all written in the Java programming language. A design pattern is a reusable, named solution to a problem that comes up over and over again when structuring a program, for example, how to create new objects, how to let parts of the system talk to each other, or how to keep certain pieces independent so they can be changed later. Instead of describing these patterns only in words, the project provides actual Java code for each one so a learner can read, run, and modify the example. The README explains that the patterns are meant to be browsed by name, by tag (such as Performance or Gang of Four), or by category (creational, behavioural, and others). Each example comes with comments and is meant to function as a small programming tutorial on how to implement that specific pattern. The maintainers point readers to a companion website for high-level descriptions and to a wiki for contribution information. The project also publishes its content as an e-book. Someone might use this repo while studying for a software engineering interview, while preparing to refactor a Java codebase that has grown messy, while teaching object-oriented programming, or to look up a respected reference implementation when they cannot remember the structure of a particular pattern. The README emphasises starting from simple principles and only reaching for patterns when the added complexity is genuinely needed. The project is released under the MIT licence.