read excel by column name java POI
<p>Good afternoon experts have a problem and I need to read the entire excel  file by column name instead of its index,example:</p>

<pre><code>Column1 | Column2 | Column3
data1      data 2    data 3
</code></pre>

<p>POI allows me to read the column index by the method <code>getColumnIndex()</code> returning for the <code>Column1 = 0 , Column2= 1 etc,</code> but I need to read it by column name <code>Column1</code> , <code>Column2</code> etc , 
there any way to do this??</p>

<p>I need to read all fields of rows and columns by column name.
attach the code which I read my file:</p>

<p>updated code:</p>

<pre><code>import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.DataFormatter;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Iterator;
import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class example {

    DataFormatter fmt = new DataFormatter();

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) throws FileNotFoundException, IOException {
        example softMarti = new example();
        FileInputStream file = new FileInputStream(new File("C:archive.xlsx"));
        XSSFWorkbook workbook = new XSSFWorkbook(file);
        XSSFSheet sheet = workbook.getSheetAt(0);
        Iterator&lt;Row&gt; rowIterator = sheet.iterator();
        while (rowIterator.hasNext()) {
            Row row = rowIterator.next();
            int rowIndex = row.getRowNum();
            if (rowIndex &lt; 1) {
                continue;
            }
            Iterator&lt;Cell&gt; cellIterator = row.cellIterator();

            while (cellIterator.hasNext()) {
                Cell cell = cellIterator.next();
                int columnIndex = cell.getColumnIndex();
                if (columnIndex != 0 &amp;&amp; columnIndex != 1 &amp;&amp; columnIndex != 4) {
                    continue;
                }
                String columnName = "";
                switch (columnIndex) {
                    case 0:
                        columnName = "column1";
                        break;
                    case 1:
                        columnName = "column2";
                        break;
                    case 4:
                        columnName = "column 4";
                        break;
                }
                String value = example.getValue(cell);
                boolean valid = example.isValid(columnIndex, value);
                if (valid) {
                    continue;
                }
                System.out.print(columnName + rowIndex);
                System.out.println(" -&gt; " + value);

            }

        }

        // TODO code application logic here
    }

    private String getValue(Cell cell) {
        switch (cell.getCellType()) {
            case Cell.CELL_TYPE_BLANK:
                return null;
            case Cell.CELL_TYPE_BOOLEAN:
                return "CELL_TYPE_BOOLEAN";
            case Cell.CELL_TYPE_ERROR:
                return "CELL_TYPE_ERROR";
            case Cell.CELL_TYPE_FORMULA:
                return "CELL_TYPE_FORMULA";
            case Cell.CELL_TYPE_NUMERIC:
                return fmt.formatCellValue(cell);
            case Cell.CELL_TYPE_STRING:
                return cell.getStringCellValue();
            default:
                return "none";

        }

    }

    boolean isValid(int column, String value) {
        if (value == null) {
            return false;
        }
        String pattern = "";
        switch (column) {
            case 0:
                pattern = "[A-Za-z0-9_\\- ]{1,20}";
                break;
            case 1:
                pattern = "[A-Za-z0-9_\\- ]{1,80}";
                break;
            case 4:
                pattern = "[0-9]{1,8}";
                break;
        }
        Pattern pat = Pattern.compile(pattern);
        Matcher mat = pat.matcher(value);
        return mat.matches();
    }
}
</code></pre>

<p>This code works but I need to validate column name  because for my project  columns may change position, that's my goal</p>