From 967d4903230d255787f59c02f52e28123ae7a5c8 Mon Sep 17 00:00:00 2001
From: Ankur <asmhatre@gmail.com>
Date: Wed, 24 Jun 2026 16:38:35 +0530
Subject: [PATCH] Command: sync post code blocks to repo exactly, Java 25,
 split merged commands, add H6 file labels and README mapping

---
 03-behavioral/command/README.md | 32 ++++++++++++++++++++++++++++++++
 README.md                       | 16 ++++++++++++++++
 2 files changed, 48 insertions(+)
 create mode 100644 03-behavioral/command/README.md

diff --git a/03-behavioral/command/README.md b/03-behavioral/command/README.md
new file mode 100644
index 0000000..6990a20
--- /dev/null
+++ b/03-behavioral/command/README.md
@@ -0,0 +1,32 @@
+# Command Design Pattern — Java Example
+
+**Pattern:** Behavioral → Command
+**Article:** https://ankurm.com/command-design-pattern-java/
+
+## What this example shows
+
+A text editor with full undo support. `Command` declares `execute()`/`undo()`/`getDescription()`. `InsertCommand` and `DeleteCommand` are concrete commands that call back into the receiver, `TextEditor`. `DeleteCommand` captures the text it's about to delete *before* deleting it, so `undo()` can restore it. `CommandHistory` is the invoker: it pushes executed commands onto a stack and pops/undoes them on request, without knowing what any command actually does.
+
+## How to run
+
+```bash
+javac command/*.java -d out/command
+java -cp out/command command.Main
+```
+
+Requires Java 25.
+
+## Post Section ↔ File Mapping
+
+| Post Section | File(s) |
+|---|---|
+| Step 1 — Command Interface | `Command.java` |
+| Step 2 — The Receiver (TextEditor) | `TextEditor.java` |
+| Step 3 — Concrete Commands | `InsertCommand.java`, `DeleteCommand.java` |
+| Step 4 — The Invoker (CommandHistory) | `CommandHistory.java` |
+| Demo | `Main.java` |
+
+Note: the `MacroCommand` snippet (Composite applied to Command) and the `Runnable`/`Callable`/`CompletableFuture` JDK snippets are illustrative only — they are not part of this repository's runnable example.
+
+Article: https://ankurm.com/command-design-pattern-java/
+All patterns: https://ankurm.com/design-patterns-java/
diff --git a/README.md b/README.md
index 832949d..6e5197a 100644
--- a/README.md
+++ b/README.md
@@ -322,6 +322,22 @@ javac 03-behavioral/chain-of-responsibility/*.java -d out/chain
 java -cp out/chain chain.Main
 ```
 
+### Command (`03-behavioral/command/`)
+
+| Post Section | File(s) |
+|---|---|
+| Step 1 — Command Interface | `Command.java` |
+| Step 2 — The Receiver (TextEditor) | `TextEditor.java` |
+| Step 3 — Concrete Commands | `InsertCommand.java`, `DeleteCommand.java` |
+| Step 4 — The Invoker (CommandHistory) | `CommandHistory.java` |
+| Demo | `Main.java` |
+
+Run it:
+```bash
+javac 03-behavioral/command/*.java -d out/command
+java -cp out/command command.Main
+```
+
 ## Reference
 
 - *Design Patterns: Elements of Reusable Object-Oriented Software* — Gamma, Helm, Johnson, Vlissides