利用poi操作execl添加行和列

package test;


import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.usermodel.WorkbookFactory;


import java.io.*;


public class FormulaToString {






public static void main(String[] args) throws Exception {
String excelPath = "D:\\poi.xlsx"; 
FileInputStream inp = new FileInputStream(excelPath);

Workbook wb = WorkbookFactory.create(inp);

CellStyle style = wb.createCellStyle();  
   Sheet sheet = wb.getSheetAt(0); // 获得第一个工作薄


// 获得总列数
int coloumNum = sheet.getRow(0).getPhysicalNumberOfCells();
int rowNum = sheet.getLastRowNum();// 获得总行数
System.out.println(coloumNum + ":" + rowNum);

Row row = sheet.getRow(0);
Cell cell= row.createCell(coloumNum);
cell.setCellFormula("A1+B1");
cell.setCellType(Cell.CELL_TYPE_FORMULA);
Row newRow=sheet.createRow(rowNum+1);//新建一行
cell=newRow.createCell(0);
cell.setCellValue(16);

FileOutputStream os = new FileOutputStream(
excelPath);
wb.write(os);
inp.close();


os.close();


}
  
 }