GroovyBook.groovy

class GroovyBook {

    String title

    static main( args ){
        Date now = new Date()
        100000.times {
            new GroovyBook( title: "title${it}")
        }
        println new Date().time - now.time
    }
}

JavaBook.java

import java.util.Date;

public class JavaBook {

    String title;

    public Book( String title ){
        this.title = title;
    }

    public static void main(String[] args){

        Date now = new Date();


        for( int i = 0; i< 100000; i++){
            new JavaBook( "title" + i );
        }

        System.out.println( ( new Date().getTime() - now.getTime() ) + "sec." );
    }
}