关于网友提出的“ POI插入数据的问题”问题疑问，本网通过在网上对“ POI插入数据的问题”有关的相关答案进行了整理，供用户进行参考，详细问题解答如下：
问题： POI插入数据的问题描述:
为什么我想一个单元格插入数据，会报NullPointerException
HSSFWorkbook wb = new HSSFWorkbook(new FileInputStream("c:\\test.xls"));
HSSFSheet sheet = wb.getSheetAt(0);
HSSFRow row = sheet.getRow((short)1);
HSSFCell cell = row.getCell((short)0);
cell.setCellValue("test");
FileOutputStream fOut = new FileOutputStream("c:\\test.xls");
wb.write(fOut);
fOut.flush();
解决方案1:
因为新创建的excel文件中，sheet,row,cell等对象都要由用户来创建
HSSFWorkbook wb = new HSSFWorkbook(new FileInputStream("c:\\test.xls"));
HSSFSheet sheet = wb.getSheetAt(0);
if(sheet=null) sheet = wb.createSheet("sheet1"); //加上这句
HSSFRow row = sheet.getRow((short)1);
if(row = null) row = sheet.createRow((short)1); // 加上这句
HSSFCell cell = row.getCell((short)0);
if(cell = null) cell = row.createCell((short)0); // 加上这句
cell.setCellValue("test");
FileOutputStream fOut = new FileOutputStream("c:\\test.xls");
wb.write(fOut);
fOut.flush();