public class ReadExcel {

    HashMap<String, List<String>> result = new HashMap<String, List<String>>();

public HashMap<String, List<String>> process() {
    try
    {
        result.clear();

        FileInputStream file = new FileInputStream(new File("C:/some.xlsx"));

        //Create Workbook instance holding reference to .xlsx file
        XSSFWorkbook workbook = new XSSFWorkbook(file);

        //Get first/desired sheet from the workbook
        XSSFSheet sheet = workbook.getSheetAt(0);

        //Iterate through each rows one by one
        Iterator<Row> rowIterator = sheet.iterator();


        while (rowIterator.hasNext()) {
            List<String> xlsList = new ArrayList<String>();

                Row row = rowIterator.next();
                Cell cell  = row.getCell(1);
                Cell cell2 = row.getCell(2);
                String key ="";
                String value="";
                xlsList.clear();
                switch (cell.getCellType())
                {
                    case Cell.CELL_TYPE_NUMERIC:
                        key = getStringCellValue(cell);
                        value = getNumericCellValue(cell2);
                        break;

                    case Cell.CELL_TYPE_STRING:
                        key = getStringCellValue(cell);
                        value = getStringCellValue(cell2);
                        break;

                }

                xlsList.add(value);
                result.put(key, xlsList);
        }
    }
}

public class DB {
    HashMap<String, List<String>> result = new HashMap<String, List<String>>();

public HashMap<String, List<String>> process() {

    result.clear();

    Connection conn = null;
    Statement stmt = null;
    List<String> carColour = new ArrayList<String>();

try {
        Class.forName("oracle.jdbc.driver.OracleDriver");
        conn = DriverManager.getConnection(DB_URL, USER, PASS);
        stmt = conn.createStatement();
        String sql1 = "SOME SQL SELECT STATEMENT THAT RETURNS 2 or more lines, by that i mean "car" has 2 values or more";
        ResultSet rs = stmt.executeQuery(sql1);

        while(rs.next()){
            carColour.add(rs.getString("colour")); // i select the column "colour"
            result.put("car", carColour);         // i put "car" as key, and "blue" and "yellow" as values
            ...................................
        }
} catch...
}

final Map<String, Boolean> comparisonResult = compareEntries(dbResult, xlsResult);
        for(final Entry<String, Boolean> entry : comparisonResult.entrySet()){
            if (entry.getValue() == false){
                System.out.println("------------------------------------------------------------------------");
                System.out.println("| Comparison FAILED | Value not matching! Column name --> " + entry.getKey() + " |");
            }
        }
        System.out.println("------------------------------------------------------------------------");
        System.out.println("DB consistency check finished.");


public static <K extends Comparable<? super K>, V>
Map<K, Boolean> compareEntries(final Map<K, V> dbResult,
    final Map<K, V> xlsResult){
    final Collection<K> allKeys = new HashSet<K>();
    allKeys.addAll(dbResult.keySet());
    allKeys.addAll(xlsResult.keySet());
    final Map<K, Boolean> result = new TreeMap<K, Boolean>();
    for(final K key : allKeys){
        result.put(key, dbResult.containsKey(key) == xlsResult.containsKey(key) && Boolean.valueOf(equal(dbResult.get(key), xlsResult.get(key))));
    }
    return result;
}

private static boolean equal(final Object obj1, final Object obj2){
    return obj1 == obj2 || (obj1 != null && obj1.equals(obj2));
}