def player = new Player(name:"Bob")
player.save()

java.lang.NoClassDefFoundError: gaming/Player

import gaming.Player

includeTargets << grailsScript("_GrailsBootstrap")

depends(configureProxy, packageApp, classpath, loadApp, configureApp, compile, bootstrap)

ApplicationHolder.application.getClassForName("gaming.Player")

import gaming.Player

import org.codehaus.groovy.grails.commons.ApplicationHolder

includeTargets << grailsScript("_GrailsInit")
includeTargets << grailsScript("_GrailsBootstrap")
includeTargets << grailsScript("_GrailsClasspath")

def handleHeaderLine(line) {
    def retval = []
    line.each {
        if(!it.equals("Game Name") && !it.equals("Total # of Copies")) {
            println("Creating Player: " + it)
            def player = new Player(name:it)
            player.save
            retval << it
        } else {
            retval << null
        }
    }
    return retval;
}

def handleGameLine(header, line) {
    println("Creating Game: " + line[0])
    for(int i = 1; i < line.length - 1; i++) {
        if(!header[i].equals("Total # of Copies")) {
            def count = line[i] == "" ? 0 : Integer.parseInt(line[i]);
            for(int j = 0; j < count; j++) {
                println "Creating copy of " + line[0] + " owned by " + header[i]
            }
        }
    }
}

target(loadAssets: "The description of the script goes here!") {
    depends(configureProxy, packageApp, classpath, loadApp, configureApp, compile, bootstrap)

    ApplicationHolder.application.getClassForName("gaming.Player")

    def tsv = new File("...")

    def header = null;
    tsv.eachLine {
        def line = it.split("t")
        if(header == null) {
            header = handleHeaderLine(line)
            println header
        } else {
            handleGameLine(header, line)
        }
    }
}

setDefaultTarget(loadAssets)

//scripts/player/PlayerScript.groovy
def handleHeaderLine(line) {
    def retval = []
    line.each {
        if(!it.equals("Game Name") && !it.equals("Total # of Copies")) {
            println("Creating Player: " + it)
            def player = new Player(name: it)
            player.save(flush: true)
            retval << it
        } else {
            retval << null
        }
    }
    return retval
}

def handleGameLine(header, line) {
    println("Creating Game: " + line[0])
    for(int i = 1; i < line.length - 1; i++) {
        if(!header[i].equals("Total # of Copies")) {
            def count = line[i] == "" ? 0 : Integer.parseInt(line[i]);
            for(int j = 0; j < count; j++) {
               println "Creating copy of " + line[0] + " owned by " + header[i]
            }
        }
    }
}

def tsv = new File("...")
def header = null
tsv.eachLine {
    def line = it.split("t")
    if(header == null) {
        header = handleHeaderLine(line)
        println header
    } else {
        handleGameLine(header, line)
    }
}

grails run-script scripts/player/PlayerScript.groovy

grails test run-script scripts/player/PlayerScript.groovy

plugins {
    if ( !System.getProperty("noTomcat") ) {
        build ":tomcat:7.0.52.1"
    }
    ....
}

grails -DnoTomcat=true run-script scripts/player/PlayerScript.groovy

includeTargets << grailsScript("_GrailsInit")
includeTargets << grailsScript("_GrailsBootstrap")

target(playerScript: "The description of the script goes here!") {
    depends configureProxy, packageApp, classpath, loadApp, configureApp

    def playerClass = classLoader.loadClass("gaming.Player")

    //Skeptical about how a domain class would behave
    //But a normal POGO should be good being used this way
    def player = playerClass.newInstance([[name: "Bob"]] as Object[])
    player.save(flush: true)

    println player
}

setDefaultTarget(playerScript)