From 5a5658c839732366f017477db3ec7d7175c38349 Mon Sep 17 00:00:00 2001
From: amin <amin@MacBook-Pro-de-amin.local>
Date: Tue, 2 Jul 2024 03:09:34 +0100
Subject: [PATCH] docs: adding subject and main

---
 .../singleton-blueprint/ExerciseRunner.java   |  5 ++
 .../checkpoints/singleton-blueprint/README.md | 46 +++++++++++++++++++
 2 files changed, 51 insertions(+)
 create mode 100644 subjects/java/checkpoints/singleton-blueprint/ExerciseRunner.java
 create mode 100644 subjects/java/checkpoints/singleton-blueprint/README.md

diff --git a/subjects/java/checkpoints/singleton-blueprint/ExerciseRunner.java b/subjects/java/checkpoints/singleton-blueprint/ExerciseRunner.java
new file mode 100644
index 000000000..7a6fe4015
--- /dev/null
+++ b/subjects/java/checkpoints/singleton-blueprint/ExerciseRunner.java
@@ -0,0 +1,5 @@
+public class ExerciseRunner {
+    public static void main(String[] args) {
+        System.out.println(GoodbyeMars.goodbyeMars());
+    }
+}
diff --git a/subjects/java/checkpoints/singleton-blueprint/README.md b/subjects/java/checkpoints/singleton-blueprint/README.md
new file mode 100644
index 000000000..227a2f063
--- /dev/null
+++ b/subjects/java/checkpoints/singleton-blueprint/README.md
@@ -0,0 +1,46 @@
+## Singleton Blueprint
+
+### Instructions
+
+You are given an incomplete singleton class. Complete the class to demonstrate your understanding of how the Singleton design pattern works. The Singleton pattern ensures that a class has only one instance and provides a global point of access to that instance.
+
+### Expected Class
+
+```java
+public class Singleton {
+    public static Singleton instance;
+
+    private Singleton() {
+        // Initialization code
+    }
+
+    public static Singleton get???() {
+        // Implementation to return the single instance
+    }
+}
+```
+
+### Usage
+
+Here is a possible `ExerciseRunner.java` to test your class:
+
+```java
+public class ExerciseRunner {
+    public static void main(String[] args) {
+        // Get the only object available
+        Singleton singleton = Singleton.getInstance();
+
+        // Show the message
+        singleton.showMessage();
+    }
+}
+```
+
+### Expected Output
+
+```shell
+$ javac *.java -d build
+$ java -cp build ExerciseRunner
+Hello, I am a singleton!
+$
+```