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Proxy: sync post code blocks to repo exactly, Java 25, add H6 file labels and README mapping

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Ankur
2026-06-24 15:49:56 +05:30
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# Proxy Design Pattern — Java Example
**Pattern:** Structural → Proxy
**Article:** https://ankurm.com/proxy-design-pattern-java/
## What this example shows
A `DatabaseConnection` interface is implemented by a real, expensive connection (`RealDatabaseConnection`) and by two proxies that sit in front of it: `LazyConnectionProxy` defers opening the real connection until the first query actually runs (virtual proxy), and `LoggingProxy` wraps any `DatabaseConnection` — real or proxied — and adds timing/audit logging around every call (cross-cutting concern proxy). Because both proxies implement the same interface as the real subject, they compose: `Main` chains `LoggingProxy` around a `LazyConnectionProxy` to get lazy loading and logging together.
## How to run
```bash
javac proxy/*.java -d out/proxy
java -cp out/proxy proxy.Main
```
Requires Java 25.
## Post Section ↔ File Mapping
| Post Section | File(s) |
|---|---|
| The Subject Interface | `DatabaseConnection.java` |
| The Real Subject | `RealDatabaseConnection.java` |
| Virtual Proxy: Lazy Initialisation | `LazyConnectionProxy.java` |
| Logging Proxy: Cross-Cutting Concerns | `LoggingProxy.java` |
| Wiring It Together: Proxy Chaining | `Main.java` |
Note: the "Dynamic Proxy with java.lang.reflect.Proxy" snippet is illustrative only — it is not part of this repository's runnable example.
Article: https://ankurm.com/proxy-design-pattern-java/
All patterns: https://ankurm.com/design-patterns-java/

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README.md
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@@ -287,6 +287,24 @@ javac 02-structural/flyweight/*.java -d out/flyweight
java -cp out/flyweight flyweight.Main java -cp out/flyweight flyweight.Main
``` ```
### Proxy (`02-structural/proxy/`)
| Post Section | File(s) |
|---|---|
| The Subject Interface | `DatabaseConnection.java` |
| The Real Subject | `RealDatabaseConnection.java` |
| Virtual Proxy: Lazy Initialisation | `LazyConnectionProxy.java` |
| Logging Proxy: Cross-Cutting Concerns | `LoggingProxy.java` |
| Wiring It Together: Proxy Chaining | `Main.java` |
Note: the "Dynamic Proxy with java.lang.reflect.Proxy" snippet is illustrative only — it is not part of this repository's runnable example.
Run it:
```bash
javac 02-structural/proxy/*.java -d out/proxy
java -cp out/proxy proxy.Main
```
## Reference ## Reference
- *Design Patterns: Elements of Reusable Object-Oriented Software* — Gamma, Helm, Johnson, Vlissides - *Design Patterns: Elements of Reusable Object-Oriented Software* — Gamma, Helm, Johnson, Vlissides