1.3 KiB
Flyweight Design Pattern — Java Example
Pattern: Structural → Flyweight Article: https://ankurm.com/flyweight-design-pattern-java/
What this example shows
A forest of 1,000 trees shares just 3 TreeType flyweight objects (one per species) instead of allocating a new heavy object per tree. TreeType holds the intrinsic (shared) state — name, color, texture. Tree holds only the extrinsic (unique) state — x/y position — plus a reference to its shared TreeType. TreeFactory is the pool manager: Map.computeIfAbsent() returns an existing flyweight or creates and caches one.
How to run
javac flyweight/*.java -d out/flyweight
java -cp out/flyweight flyweight.Main
Requires Java 25.
Post Section ↔ File Mapping
| Post Section | File(s) |
|---|---|
| Step 1 — The Flyweight (TreeType) | TreeType.java |
| Step 2 — The Factory (TreeFactory) | TreeFactory.java |
| Step 3 — The Context (Tree) | Tree.java |
| Putting the Forest Together | Main.java |
Note: the "Flyweight in the JDK: String Pool and Integer Cache" and "Measuring the Benefit" snippets are illustrative only — they are not part of this repository's runnable example.
Article: https://ankurm.com/flyweight-design-pattern-java/ All patterns: https://ankurm.com/design-patterns-java/