poi方式读取Excel文件

package poi;

import java.io.File;
import java.io.IOException;
import java.util.Date;

import org.apache.commons.io.FileUtils;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

public class PoiReadExcel {

    public static void main(String[] args) {
        
        File file = new File("e:/poi_exp.xls");
        
        try {
            HSSFWorkbook workbook = new HSSFWorkbook(FileUtils.openInputStream(file));
            HSSFSheet sheet = workbook.getSheet("Sheet0");//getSheetAt(index);
            int firstRowNum = 0;
            //获取最后一行行号
            int lastRowNum =sheet.getLastRowNum();
            for (int i = firstRowNum; i < lastRowNum; i++) {
                HSSFRow row = sheet.getRow(i);
                //获取当前行的最后一个单元格列号
                int lastCellNum = row.getLastCellNum();
                for (int j = 0; j < lastCellNum; j++){
                    HSSFCell cell = row.getCell(j);
                    if(cell != null){
                        //获取数据类型
                        switch (cell.getCellType()) {
                        //整型
                        case HSSFCell.CELL_TYPE_NUMERIC:
                            if(HSSFDateUtil.isCellDateFormatted(cell)){
                                Date date = cell.getDateCellValue();
                                System.out.println(date.toString());
                            }else{
                                int val = (int)cell.getNumericCellValue();
                                System.out.print(val + " ");
                                break;
                            }
                        //字符串
                        case HSSFCell.CELL_TYPE_STRING:
                            String val1 = cell.getStringCellValue();
                            System.out.print(val1 + " ");
                            break;

                        default:
                            System.out.println("what's heppend?");
                            break;
                        }
                    }                    
                }
                System.out.println();
            }
            workbook.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}