Using Apache POI how to read a specific excel column

Question

I'm having a problem in excel while using Apache POI. I can read across rows, but sometimes I'm in a situation where I would like to read a particular column only.

So is it possible to read any particular column like only the 'A' column only or the column 'C' only.

I'm using the Java language for this.

Answer 1

heikkim is right, here is some sample code adapted from some code I have:

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Row;
...
for (int rowIndex = 0; rowIndex <= sheet.getLastRowNum(); rowIndex++) {
  row = sheet.getRow(rowIndex);
  if (row != null) {
    Cell cell = row.getCell(colIndex);
    if (cell != null) {
      // Found column and there is value in the cell.
      cellValueMaybeNull = cell.getStringCellValue();
      // Do something with the cellValueMaybeNull here ...
      // break; ???
    }
  }
}

For the colCount use something like row.getPhysicalNumberOfCells()

Answer 2

  Sheet sheet  = workBook.getSheetAt(0); // Get Your Sheet.

  for (Row row : sheet) { // For each Row.
      Cell cell = row.getCell(0); // Get the Cell at the Index / Column you want.
  }

My solution, a bit simpler code wise.

Answer 3

Okay, from your question, you just simply want to read a particular column. So, while iterating over a row and then on its cells, your can simply check the index of the column.

Iterator<Row> rowIterator = mySheet.iterator(); // Traversing over each row of XLSX file
        while (rowIterator.hasNext()) {
            Row row = rowIterator.next(); // For each row, iterate through each columns
            Iterator<Cell> cellIterator = row.cellIterator();
            while (cellIterator.hasNext()) {
                Cell cell = cellIterator.next();
                println "column index"+cell.getColumnIndex()//You will have your columns fixed in Excel file
                if(cell.getColumnIndex()==3)//for example of c
                {
                print "done"            
                }
          }
     }     

I am using POI 3.12-- 'org.apache.poi:poi:3.12' Hope it helps. Cheers!

Answer 4

您可以循环行并从每一行读取相同的单元格（这不包括一列吗？）。

Answer 5

import java.io.*;

import org.apache.poi.hssf.util.CellReference;
import org.apache.poi.ss.usermodel.*;
import java.text.*;

public class XSLXReader {
    static DecimalFormat df = new DecimalFormat("#####0");

    public static void main(String[] args) {
        FileWriter fostream;
        PrintWriter out = null;
        String strOutputPath = "H:\\BLR_Team\\Kavitha\\Excel-to-xml\\";
        String strFilePrefix = "Master_5.2-B";

        try {
            InputStream inputStream = new FileInputStream(new File("H:\\BLR_Team\\Kavitha\\Excel-to-xml\\Stack-up 20L pure storage 11-0039-01 ISU_USA-A 1-30-17-Rev_exm.xls"));
            Workbook wb = WorkbookFactory.create(inputStream);
           // Sheet sheet = wb.getSheet(0);
            Sheet sheet =null;
            Integer noOfSheets= wb.getNumberOfSheets();

            for(int i=0;i<noOfSheets;i++){
                sheet = wb.getSheetAt(i);
                System.out.println("Sheet : "+i + " " + sheet.getSheetName());
                System.out.println("Sheet : "+i + " " + sheet.getFirstRowNum());
                System.out.println("Sheet : "+i + " " + sheet.getLastRowNum());

            //Column 29
            fostream = new FileWriter(strOutputPath + "\\" + strFilePrefix+i+ ".xml");
            out = new PrintWriter(new BufferedWriter(fostream));

            out.println("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
            out.println("<Bin-code>");

            boolean firstRow = true;
            for (Row row : sheet) {
                if (firstRow == true) {
                    firstRow = false;
                    continue;
                }
                out.println("\t<DCT>");
                out.println(formatElement("\t\t", "ID", formatCell(row.getCell(0))));
                out.println(formatElement("\t\t", "Table_name", formatCell(row.getCell(1))));
                out.println(formatElement("\t\t", "isProddaten", formatCell(row.getCell(2))));
                out.println(formatElement("\t\t", "isR3P01Data", formatCell(row.getCell(3))));

                out.println(formatElement("\t\t", "LayerNo", formatCell(row.getCell(29))));
                out.println("\t</DCT>");
            }
            CellReference ref = new CellReference("A13");
          Row r = sheet.getRow(ref.getRow());
          if (r != null) {
             Cell c = r.getCell(ref.getCol());
           System.out.println(c.getRichStringCellValue().getString());
          }

            for (Row row : sheet) {
                  for (Cell cell : row) {

                      CellReference cellRef = new CellReference(row.getRowNum(), cell.getColumnIndex());


                      switch (cell.getCellType()) {
                      case Cell.CELL_TYPE_STRING:
                          System.out.println(cell.getRichStringCellValue().getString());
                          break;
                      case Cell.CELL_TYPE_NUMERIC:
                          if (DateUtil.isCellDateFormatted(cell)) {
                              System.out.println(cell.getDateCellValue());
                          } else {
                              System.out.println(cell.getNumericCellValue());
                          }
                          break;
                      case Cell.CELL_TYPE_BOOLEAN:
                          System.out.println(cell.getBooleanCellValue());
                          break;
                      case Cell.CELL_TYPE_FORMULA:
                          System.out.println(cell.getCellFormula());
                          break;
                      case Cell.CELL_TYPE_BLANK:
                          System.out.println();
                          break;
                      default:
                          System.out.println();
                  }
                  }

            }
            out.write("</Bin-code>");
            out.flush();
            out.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static String formatCell(Cell cell)
    {
        if (cell == null) {
            return "";
        }
        switch(cell.getCellType()) {
            case Cell.CELL_TYPE_BLANK:
                return "";
            case Cell.CELL_TYPE_BOOLEAN:
                return Boolean.toString(cell.getBooleanCellValue());
            case Cell.CELL_TYPE_ERROR:
                return "*error*";
            case Cell.CELL_TYPE_NUMERIC:
                return XSLXReader.df.format(cell.getNumericCellValue());
            case Cell.CELL_TYPE_STRING:
                return cell.getStringCellValue();
            default:
                return "<unknown value>";
        }
    }

    private static String formatElement(String prefix, String tag, String value) {
        StringBuilder sb = new StringBuilder(prefix);
        sb.append("<");
        sb.append(tag);
        if (value != null && value.length() > 0) {
            sb.append(">");
            sb.append(value);
            sb.append("</");
            sb.append(tag);
            sb.append(">");
        } else {
            sb.append("/>");
        }
        return sb.toString();
    }
}

This code does 3 things:

1. Excel to XML file generation. Eng. Name Dong Kim
2. Prints the content of a particular cell : A13
3. Also print the excel content into normal text format. Jars to be imported: poi-3.9.jar,poi-ooxml-3.9.jar,poi-ooxml-schemas-3.9.jar,xbea‌​n-2.3.0.jar,xmlbeans‌​-xmlpublic-2.4.0.jar‌​,dom4j-1.5.jar

Answer 6

Here is the code to read the excel data by column.

public ArrayList<String> extractExcelContentByColumnIndex(int columnIndex){
        ArrayList<String> columndata = null;
        try {
            File f = new File("sample.xlsx")
            FileInputStream ios = new FileInputStream(f);
            XSSFWorkbook workbook = new XSSFWorkbook(ios);
            XSSFSheet sheet = workbook.getSheetAt(0);
            Iterator<Row> rowIterator = sheet.iterator();
            columndata = new ArrayList<>();

            while (rowIterator.hasNext()) {
                Row row = rowIterator.next();
                Iterator<Cell> cellIterator = row.cellIterator();
                while (cellIterator.hasNext()) {
                    Cell cell = cellIterator.next();

                    if(row.getRowNum() > 0){ //To filter column headings
                        if(cell.getColumnIndex() == columnIndex){// To match column index
                            switch (cell.getCellType()) {
                            case Cell.CELL_TYPE_NUMERIC:
                                columndata.add(cell.getNumericCellValue()+"");
                                break;
                            case Cell.CELL_TYPE_STRING:
                                columndata.add(cell.getStringCellValue());
                                break;
                            }
                        }
                    }
                }
            }
            ios.close();
            System.out.println(columndata);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return columndata;
    }

Answer 7

Please be aware, that iterating through the columns using row cell iterator ( Iterator<Cell> cellIterator = row.cellIterator(); ) may lead to silent skipping columns. I have just encountered a document that was exposing such behaviour.

Iterating using indexes in a for loop and using row.getCell(i) was not skipping columns and was returning values at the correct column indexes.