import java.util.Calendar;
import java.util.HashMap;
import java.util.Map;
import javax.jcr.Node;
import javax.jcr.RepositoryException;
import javax.jcr.Session;
import org.apache.commons.lang3.StringUtils;
import info.magnolia.jcr.util.NodeUtil;
import info.magnolia.context.MgnlContext;
import info.magnolia.jcr.util.NodeTypes;
import java.time.Instant;
import java.time.temporal.ChronoUnit;

MAX_DEPTH = 4;
PAGES_PER_LEVEL = 8;
START_NODE_PATH = "/travel";
counter=0;

mapping = new HashMap<>();
mapping.put(1, "a");
mapping.put(2, "b");
mapping.put(3, "c");
mapping.put(4, "d");
mapping.put(5, "e");
mapping.put(6, "f");
mapping.put(7, "g");
mapping.put(8, "h");
mapping.put(9, "i");
mapping.put(10, "j");

void createNodes(Node root, int depth) throws RepositoryException {
        if (depth > MAX_DEPTH) {
            return;
        }

        for (int i = 1; i <= PAGES_PER_LEVEL; ++i) {
            String letter = mapping.get(i);
            letter = StringUtils.isBlank(letter) ? String.valueOf(i) : letter;
            Node node = createNode(root, "Level-" + depth + "-" + letter);
            createNodes(node, depth+1);
        }
        ++depth;
     }

    Node createNode(Node root, String name) throws RepositoryException {
    println "Create Node "+name+" under "+root.getPath();

    Node page = NodeUtil.createPath(root, name, NodeTypes.Page.NAME);
        page.setProperty("title", name);
        page.setProperty("metaKeywords", "test");
        page.setProperty("mgnl:created", Calendar.getInstance());
        page.setProperty("mgnl:createdBy", "superuser");
        page.setProperty("mgnl:lastModified", Calendar.getInstance());
        page.setProperty("mgnl:lastModifiedBy", "superuser");
        page.setProperty("mgnl:template", "travel-demo:pages/home");

        createAreaNode(page, "stage");
        createAreaNode(page, "content-main-standard");
        createAreaNode(page, "footer");

        ++counter;
        return page;
}

    void createAreaNode(Node root, String areaName) throws RepositoryException {
        Node area = NodeUtil.createPath(root, areaName, NodeTypes.Area.NAME);
        area.setProperty("mgnl:created", Calendar.getInstance());
        area.setProperty("mgnl:createdBy", "superuser");
        area.setProperty("mgnl:lastModified", Calendar.getInstance());
        area.setProperty("mgnl:lastModifiedBy", "superuser");
    }

    //////// START Script //////
    println "Start creating TEST DATA "
    Instant start = Instant.now();   
    Session session = MgnlContext.getJCRSession("website");
    Node rootNode = session.getNode(START_NODE_PATH);
    createNodes(rootNode, 1);
    session.save();
    println "Created "+counter+" nodes in "+ChronoUnit.MILLIS.between(start,Instant.now())+" ms"
    println "FINISHED creating TEST DATA "

2020-12-16 17:15:52,276 ERROR nfo.magnolia.admincentral.AdmincentralErrorHandler: AdmincentralUI has encountered an unhandled exception.
java.util.concurrent.ExecutionException: java.lang.StackOverflowError
at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:?]