how do you test using excel files code example

Example: how do you test using excel files

How do you do test using excel files in Java?
I use Apache POI libraries to read and write
from excel file, I add the Apache POI
dependencies to my pom file. In order
to connect I use following classes.
 	-FileInputStream from Java. it is
    used to create connection to the file.
    We pass the file path as constructor to it.
 	-WorkBook is a class that represents
    the excel file.  We create Workbook object
    using the FileInputStream object.
 	-Sheet represents a single sheet from 
    the excel file. We create sheet using 
    Workbook object. We can create worksheet
    using the 0 based index.

	public String readExcel(String path, String sheetName,
                                         int rowNum, int colNum) {
        try {
            FileInputStream file = new FileInputStream(path);
            Workbook book = WorkbookFactory.create(file);
            Sheet sheet = book.getSheet(sheetName);
            Row row = sheet.getRow(rowNum);
	    	Cell cell = row.getCell(colNum);
            String cellData = cell.toString();
            return cellData;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

How to get row and column numbers:
    int rowCount = sheet.getLastRowNum()+1; ==> why we add '+1'? 
                                         Because row num starts from 0.
    int colCount = sheet.getRow(0).getLastCellNum();
    String sheetName = workSheet.getSheetName();