Add reproducible Gradle build and application launch checks

.github/workflows/build.yml

@@ -0,0 +1,26 @@
+name: Build and launch
+on:
+  push:
+    branches: [master]
+  pull_request:
+  workflow_dispatch:
+permissions:
+  contents: read
+concurrency:
+  group: build-${{ github.ref }}
+  cancel-in-progress: true
+jobs:
+  build:
+    name: Compile, package and launch (Java 8)
+    runs-on: ubuntu-24.04
+    timeout-minutes: 15
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad # v6
+        with:
+          distribution: temurin
+          java-version: '8'
+      - name: Build and run through Gradle
+        run: bash ./gradlew --no-daemon clean build run
+      - name: Launch the packaged application
+        run: java -jar build/libs/ExampleApp.jar

README.md

@@ -0,0 +1,8 @@
+# ExampleApp
+
+A minimal Java console application built with the checked-in Gradle 5.2 wrapper and Java 8.
+
+Build and launch: `bash ./gradlew --no-daemon clean build run`.
+Run the packaged application: `java -jar build/libs/ExampleApp.jar`.
+
+GitHub Actions checks compilation, packaging and both launch paths on pushes and pull requests. The existing JUnit method is an empty placeholder, so a successful build is not evidence of functional test coverage.

build.gradle

@@ -15,9 +15,9 @@ plugins {
 }
 
 repositories {
-    // Use jcenter for resolving your dependencies.
+    // Resolve dependencies from Maven Central.
     // You can declare any Maven/Ivy/file repository here.
-    jcenter()
+    mavenCentral()
 } 
 
 dependencies {
@@ -33,11 +33,13 @@ test {
 	}
 }
 
+mainClassName = 'main.java.ExampleApp.Main'
+
 jar {
 	manifest {
-		attributes 'Main-Class': 'main.java.ExampleApp.Main'
+		attributes 'Main-Class': mainClassName
 	}
 }
 
 // Define the main class for the application
-mainClassName = 'ExampleApp.Main'
+