使用java将数据从多个arrayLists导出到单个excel表

Question

I have two arraylists each containing certain integer values, my challenge is to print the each arraylist data in each column in the excel sheet using java. For this I have used apache POI. When I execute the below code only one column is writing and the other column is empty.

• For this I have used two classes, the main class is below.

package basic;
import java.io.IOException;
import java.util.*;
public class excel {

    public static void main(String[] args) throws IOException, InterruptedException {
        SimpleExcelWriterExample.createRecord();
        List<Integer> values1=Arrays.asList(1,2,3,4,5,6);
        List<Integer> values2=Arrays.asList(1,2,3,4,5,6);
        SimpleExcelWriterExample.AddRecord(values1,0);
        SimpleExcelWriterExample.AddRecord(values2,1);
        SimpleExcelWriterExample.Add();

    }

}

SimpleExcelWriterExample class is below

package basic;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;
import org.apache.poi.xssf.usermodel.*;
class SimpleExcelWriterExample {

    public static XSSFWorkbook workbook;
    public static XSSFSheet worksheet;
    public static FileOutputStream fileOut;
    public static XSSFRow row;
    public static XSSFCell cell;

    public static void createRecord()throws IOException {

        fileOut = new FileOutputStream("C:\\Users\\DELL\\workspace\\wipro1\\src\\basic\\New.xlsx");
        workbook = new XSSFWorkbook();
        worksheet = workbook.createSheet("POI Worksheet");
        System.out.println("Sheet creadted successfully");

    }

    public static void AddRecord(List<Integer> values, int col) throws IOException {
        for (int i = 0; i < values.size(); i++) {
            row = worksheet.createRow(i);
            cell = row.createCell(col);
            cell.setCellValue(values.get(i));
            //System.out.println(cellAj.getStringCellValue());  
        }
        }

    public static void Add() throws IOException {
        workbook.write(fileOut);

    }

}

-The output I am getting is below enter image description here

Please help me sort out this problem, Thanks in advance.

Answer 1

Sheet.createRow always creates a new empty row in the sheet. So in your AddRecord method do

row = worksheet.getRow(i); if (row == null) row = worksheet.createRow(i);

That first tries getting the row and only if the row is not present already, then it creates the row.

So full AddRecord method could look like:

public static void AddRecord(List<Integer> values, int col) throws IOException {
 for (int i = 0; i < values.size(); i++) {
  row = worksheet.getRow(i); if (row == null) row = worksheet.createRow(i);
  cell = row.createCell(col); 
  cell.setCellValue(values.get(i));
  //System.out.println(cellAj.getStringCellValue());  
 }
}