Gradle

build.gradle

repositories {
    mavenCentral()
}

apply plugin: "java"

dependencies {
    compile "org.apache.commons:commons-lang3:3.3.2"
}

sourceSets {
    main.java.srcDir "src/main"
    test.java.srcDir "src/test"
}

jar {
    from configurations.compile.collect { zipTree it }
    manifest.attributes "Main-Class": "com.example.myproject.Main"
}

Main.java

package com.example.myproject

import java.util.Arrays;
import org.apache.commons.lang3.StringUtils;

public class Main {
    public static void main(String[] args) {
        System.out.println(StringUtils.swapCase(Arrays.toString(args)));
    }
}