使用Apache POI编写excel文件，但FileOutput只包含一列

Question

我编写了一个代码，它从一个输入 excel 文件中获取数据，并编写一个具有所需组织的新输出文件。我遇到的问题是，当我打开 Java 文件时，只有 for 循环中最新的列有数据。我已经通过在不同时间打破 for 循环来测试我的 for 循环是否错误。测试表明它确实在正确的列中写入了正确的数据。我不知道它为什么选择删除上一列。我是否缺少一行来保存我刚刚制作的单元格值，以将数据保留在我正在处理的工作表上？

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Row;

import org.apache.poi.ss.usermodel.SheetConditionalFormatting;
import org.apache.poi.ss.usermodel.ConditionalFormattingRule;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.ComparisonOperator;//compare two different values
import org.apache.poi.ss.usermodel.PatternFormatting;
import org.apache.poi.ss.usermodel.IndexedColors;


 import java.util.Iterator;
import java.io.*;
import javax.swing.JFileChooser;

public class Reorganizer 
{
public static void main(String[] args)
{
    /*File Chooser*/
    JFileChooser fileChooser = new JFileChooser();//lets user choose file
    int returnValue = fileChooser.showOpenDialog(null);//null bc we don't have parent classes, lets user choose through an open window

    if(returnValue == JFileChooser.APPROVE_OPTION)
    {
        try 
        {
            Workbook wb= new HSSFWorkbook(new FileInputStream(fileChooser.getSelectedFile()));//setting the input file as a workbook
            Sheet inputSheet = wb.getSheetAt(0);//the sheet from the input file

            Workbook wb1 = new HSSFWorkbook();//creating a new workbook to later be put into the output file
            Sheet outputSheet = wb1.createSheet("Sheet 1");//creates new sheet on the output excel file

            //first need something to find cell# of the file
            Row idRow = inputSheet.getRow(0);
            int cellCounter=0;
            for(Iterator<Cell> cit = idRow.cellIterator(); cit.hasNext();)//goes down the row, until there is nothing
            {                   
                Cell cell = cit.next();
                cellCounter++;
            }
            //finds the number of rows
            int rowCounter=0;
            for(Iterator<Row> rit = inputSheet.rowIterator();rit.hasNext();)//goes down the column, until there is nothing
            {                   
                Row row = rit.next();
                rowCounter++;
            }


            //The first row of the document should be the labeling process
            //Set the row(0) and the cells(9)
            Row labelRow = outputSheet.createRow(0);
            //for loop to make 9 cells with labels
            String[] cellValues = new String[]{"Chr","Pos","Olfr","Subfamily","Cluster","OP6u","OP6d","OP27u","OP27d"};
            for(int i=0; i<=9;i++)
            {
                Cell labelCells = labelRow.createCell(i);
                if(i<=8)
                {
                     labelCells.setCellValue(cellValues[i]);
                     for(Iterator<Cell> cit = idRow.cellIterator(); cit.hasNext(); )
                        {
                            Cell cell = cit.next();
                            cell.setCellType(Cell.CELL_TYPE_STRING);
                            if(cellValues[i].equals(cell.getStringCellValue()))
                            {
                                for(int j=1;j<rowCounter;j++)
                                {
                                    int cellnum = cell.getColumnIndex();
                                    Cell inputCell = inputSheet.getRow(j).getCell(cellnum);
                                    inputCell.setCellType(Cell.CELL_TYPE_STRING);
                                    String data = inputCell.getStringCellValue();
                                    Cell outputCell = outputSheet.createRow(j).createCell(i);
                                    outputCell.setCellValue(data);
                                    System.out.println(cellnum);//tells me where the input column was from
                                    System.out.println(i);////tells me what row cell I'm writing on
                                    System.out.println(j);//tells me what row number 
                                    System.out.println(data);//tells me the data being inputed into file
//used the above prints to find out what it was doing, 
//this is the code used to write the data


                                }
                            }

                        }
                } 
                else 
                {
                     labelCells.setCellValue("");
                }

            }

        FileOutputStream output = new FileOutputStream("Reorganized.xls");
        wb1.write(output);
        output.flush();
        output.close();
        }
        catch (FileNotFoundException e) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
        catch (IOException e) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }


    }

}

}   

Answer 1

您的问题似乎就在这里。当您调用 createRow() 时，它将删除现有数据。

Cell outputCell = outputSheet.createRow(j).createCell(i);

您可以在填充数据之前预先创建所有行，也可以调用 getRow() 来测试该行是否已经存在。你需要这样的东西：

Row row = outputSheet.getRow(j);
if (row == null) {
    row = outputSheet.createRow(j);
}
Cell outputCell = row.createCell(i);