使用POI获取Excel实际行数与异常处理

package test;  
      
    import java.io.FileInputStream;  
      
    import org.apache.poi.hssf.usermodel.HSSFWorkbook;  
    import org.apache.poi.hssf.util.CellReference;  
    import org.apache.poi.ss.usermodel.Cell;  
    import org.apache.poi.ss.usermodel.Row;  
    import org.apache.poi.ss.usermodel.Sheet;  
    import org.apache.poi.ss.usermodel.Workbook;  
      
    public class test2{  
        public static void main(String[] args) {  
            Workbook wb = null;  
            try {  
                wb = new HSSFWorkbook(new FileInputStream("E:\\Workspaces\\testdata\\仓库数据.xls"));  
            } catch (Exception e) {  
                  //  
            }  
            Sheet sheet = wb.getSheetAt(0);  
            CellReference cellReference = new CellReference("A4");  
            boolean flag = false;  
            System.out.println("总行数："+(sheet.getLastRowNum()+1));  
            for (int i = cellReference.getRow(); i <= sheet.getLastRowNum();) {  
                Row r = sheet.getRow(i);  
                if(r == null){  
                    // 如果是空行（即没有任何数据、格式），直接把它以下的数据往上移动  
                    sheet.shiftRows(i+1, sheet.getLastRowNum(),-1);  
                    continue;  
                }