Question: Trying to run simple code that writes a dataframe as a csv file using spark and Java. java.lang.NoClassDefFoundError: org/apache/spark/sql/Dataset

Here is my simple code:
package org.example;

import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.RowFactory;
import org.apache.spark.sql.SparkSession;
import org.apache.spark.sql.types.DataTypes;
import org.apache.spark.sql.types.StructField;
import org.apache.spark.sql.types.StructType;

import java.util.Arrays;
import java.util.List;

public class Main {
    public static void writeOutput(Dataset<Row> df, String outputPath) {
        df.write()
                .option("header", "true")
                .option("delimiter", "\t")
                .csv(outputPath);
    }
    public static void main(String[] args) {

        // Create a SparkSession
        SparkSession spark = SparkSession.builder()
                .appName("DataFrameWriter")
                .getOrCreate();

        // Create a DataFrame (assuming df is already defined)
        List<Row> data = Arrays.asList(
                RowFactory.create("John", 25, "New York"),
                RowFactory.create("Alice", 30, "San Francisco"),
                RowFactory.create("Bob", 35, "Chicago")
        );

        StructType schema = DataTypes.createStructType(new StructField[] {
                DataTypes.createStructField("name", DataTypes.StringType, true),
                DataTypes.createStructField("age", DataTypes.IntegerType, true),
                DataTypes.createStructField("city", DataTypes.StringType, true)
        });

        Dataset<Row> df = spark.createDataFrame(data, schema);

        // Specify the output path
        String outputPath = "src/main/java/output";

        // Call the writeOutput method
        writeOutput(df, outputPath);

        // Stop the SparkSession
        spark.stop();
    }
}

Here is my build.gradle file:
plugins {
    id 'java'
}

group = 'org.example'
version = '1.0-SNAPSHOT'

repositories {
    mavenCentral()
}

dependencies {
    compileOnly 'org.apache.spark:spark-sql_2.12:3.2.0'
    implementation 'org.apache.spark:spark-core_2.12:3.2.0'


    testImplementation platform('org.junit:junit-bom:5.9.1')
    testImplementation 'org.junit.jupiter:junit-jupiter'
}

test {
    useJUnitPlatform()
}

And errors:
Task :Main.main() FAILED
Error: Unable to initialize main class org.example.Main
Caused by: java.lang.NoClassDefFoundError: org/apache/spark/sql/Dataset

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':Main.main()'.
> Process 'command '/Library/Java/JavaVirtualMachines/jdk-11.0.11.jdk/Contents/Home/bin/java'' finished with non-zero exit value 1

java -version:
java version "11.0.19" 2023-04-18 LTS
Java(TM) SE Runtime Environment 18.9 (build 11.0.19+9-LTS-224)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.19+9-LTS-224, mixed mode)

scala -version:
Scala code runner version 3.3.0 -- Copyright 2002-2023, LAMP/EPFL

Spark: version 3.4.0
Using Scala version 2.12.17 (OpenJDK 64-Bit Server VM, Java 17.0.7)
Could you tell me what could be wrong? Pretty simple code, just can't figure out what to check. I've already tried reinstalling everything.


Answer:
Avoid using compileOnly directive for dependencies which implementation will be needed during runtime as stated on Gradle's Java library plugin user guide https://docs.gradle.org/current/userguide/java_library_plugin.html and blog https://blog.gradle.org/introducing-compile-only-dependencies