ReadingBat Java Content

Java and Kotlin programming challenges for the ReadingBat platform. This repository defines challenge content that the ReadingBat server renders as interactive coding exercises.

Getting Started

Requires JDK 17+.

./gradlew build -x test         # Compile
./gradlew run                   # Start the content server on http://localhost:8080
./gradlew --rerun-tasks check   # Run all tests
./gradlew test --tests "ContentTests"           # Run a single test class
./gradlew test -Dkotest.filter.tests="<name>"   # Filter Kotest cases by name
make uberjar                    # Build fat jar at build/libs/server.jar

When running locally, challenge files are loaded directly from disk (via FileSystemSource), so edits are picked up on reload without a rebuild. Production builds load content from this GitHub repository.

Challenge Structure

Each challenge is a standalone source file with a main() that prints expected outputs. Those output lines become the answer key for the exercise.

Java (src/main/java/<package>/):

// @desc Determine if one value is less than another with the **<** operator.
public class LessThan {
    public static boolean compare(int val1, int val2) {
        return val1 < val2;
    }
    public static void main(String[] args) {
        System.out.println(compare(4, 6));   // true
        System.out.println(compare(12, 8));  // false
    }
}

Kotlin (src/main/kotlin/<package>/):

fun doubleIt(i: Int): Int = i * 2

fun main() {
    println(doubleIt(5))   // 10
    println(doubleIt(10))  // 20
}

All challenges are registered in src/main/kotlin/Content.kt using the readingBatContent DSL.