删除最后一行Excel时出错-Apache POI

Question

I am trying to delete last 10 rows using Apache-POI. I tried to find solutions online, no luck. My code:

 import java.io.*;
 import org.apache.poi.hssf.usermodel.HSSFRow;
 import org.apache.poi.sl.usermodel.Sheet;
 import org.apache.poi.xssf.usermodel.*;


    public class Sample1 {

        public static void main(String[] args)throws Exception
        {

            File file = new File("File.xlsx");
            FileInputStream fIP = new FileInputStream(file);
            XSSFWorkbook wb = new XSSFWorkbook(fIP);
            XSSFSheet sheet = wb.getSheetAt(1);
            int lastRowNum = sheet.getLastRowNum()+1;
            //XSSFRow removingRow = sheet.getRow(lastRowNum);


            if(file.isFile() && file.exists())
            {

                for (int i = lastRowNum; i>= lastRowNum-10 ; i-- )
                {
                XSSFRow removingRow = sheet.getRow(i);
                sheet.removeRow(removingRow);
                }

            }

            else
            {
                System.out.println("Error in opening the file");
            }   
    }   
    }

Error:

Exception in thread "main" java.lang.NullPointerException
at org.apache.poi.xssf.usermodel.XSSFSheet.removeRow(XSSFSheet.java:1914) at Sample1.main(Sample1.java:27)

Jar Files:

dom4J-1.6.1 
poi-3.16 
poi-3.17-beta 
poi-ooxml-3.15.0
poi-ooxml-schemas-3.15.0 
xmlbeans-2.6.0 
commons-collections4-4.0
commons-collections4-4.1 
commons-codec-1.10 
commons-logging-1.2
maven-ant-tasks-2.1.3

Any help is appreciated.

Thanks in advance.

Answer 1

Off-by-one error:

for (int i = lastRowNum; i>= lastRowNum-10 ; i-- )

should be:

for (int i = lastRowNum - 1; i>= Math.max(lastRowNum-10, 0) ; i-- )