Load data from excel

first option:

get the schema behind *.XSLX and import it using  XML Schema wizard.
It's incredible huge covering all XLS features you know and also that you don't want to know.
several hundred classes. XML Schema Wizard
I gave up by lack of understanding where to start. I'm not strong with XLS features.

second option:

use ActiveX_64  to access *.XLS
in Windows, your Studio has an Activate wizard that creates access to your local installed DLL.
so you need to have EXCEL installed on your server.

The wizard generates still a remarkable number of classes but it is more comprehensive
using them you can do Scripting in EXCEL. Activate Wizard

be careful to really get the 64bit version of the DLL
 

There are several approaches available:

1. Automatic conversion of XSL(X) to CSV is possible using LibreOffice. Here's an article on how to do that.

2. Use Java library, such as Apache POI to traverse the cells and send results back. To send results back quickly and efficiently you can use String[] type and fill it with $lb built on Java side. String[] would become %ListOfDataTypes in Cache and $lb would remain $lb.

I've done some preliminary work but didn't get around to finishing or publishing it so here's a sample code that outputs list to console:

package isc.poi;

import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.usermodel.Row;

import java.util.ArrayList;
import java.util.Iterator;
import java.io.File;

import static org.apache.poi.ss.usermodel.CellType.*;

public class Main {

    public static String ROWSEPARATOR = "\t\t\t";

    public static void main(String[] args) {
        try {
            Test1();
        } catch (Exception ex) {
        }
    }

    public static String[] Test1 () throws Exception{
        ArrayList<String> list = new ArrayList<String>();

        File file = GetFile();
        Workbook workbook = WorkbookFactory.create(file);
        Iterator<Sheet> sheetIterator = workbook.sheetIterator();
        while(sheetIterator.hasNext()){
            Sheet sheet = sheetIterator.next();
            String name  = sheet.getSheetName();
            String value = null;

            Iterator rows = sheet.rowIterator();
            while (rows.hasNext()) {
                Row row = (Row) rows.next();

                for(int i=0; i<row.getLastCellNum(); i++) {
                    Cell cell = row.getCell(i, Row.MissingCellPolicy.CREATE_NULL_AS_BLANK);
                    if (cell.getCellTypeEnum() == FORMULA) {
                        switch(cell.getCachedFormulaResultTypeEnum()) {
                            case NUMERIC:
                                value = String.valueOf(cell.getNumericCellValue());
                                break;
                            case STRING:
                                value = cell.getRichStringCellValue().getString();
                                break;
                        }
                    } else {
                        value = cell.toString();
                    }
                    list.add(value);
                    ///System.out.print("'" + cell.toString() + "'"+" ");
                }
                list.add(ROWSEPARATOR);
                System.out.println();
            }


            /*for (Row row : sheet) {
                for (Cell cell : row) {
                    System.out.print(cell.toString()+" ");
                    //int i=1;
                }
                System.out.println();
            }*/
        }
        String[] result = list.toArray(new String[list.size()]);
        return result;
    }

    public static File GetFile () {
        File file = new File("D:\\Cache\\POI\\Book1.xlsx");

        return file;
    }

    public static Object Test(Object in)
    {
        String[] ret = new String[1];
        ret[0] = "144";
        return ret;
    }
}