java POI读取Excel文件详解编程语言

import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.util.ArrayList; 
import java.util.Iterator; 
import java.util.List; 
import java.util.Map; 
 
import org.apache.commons.logging.Log; 
import org.apache.commons.logging.LogFactory; 
import org.apache.poi.hssf.usermodel.HSSFCell; 
import org.apache.poi.hssf.usermodel.HSSFRow; 
import org.apache.poi.hssf.usermodel.HSSFSheet; 
import org.apache.poi.hssf.usermodel.HSSFWorkbook; 
import org.apache.poi.poifs.filesystem.POIFSFileSystem; 
 
import com.neusoft.counter.vo.LoginIdStaffNo; 
 
public class ExcelDemo { 
 
	private static final Log log = LogFactory.getLog(ExcelDemo.class); 
 
	public List parseExcel(File in) { 
		List arrayList = new ArrayList(); 
 
		FileInputStream fis = null; 
		POIFSFileSystem fs = null; 
 
		try { 
			fis = new FileInputStream(in); 
			fs = new POIFSFileSystem(fis); 
 
			HSSFWorkbook wb = new HSSFWorkbook(fs); 
			// first sheet 
			HSSFSheet sheet = wb.getSheetAt(0); 
			int lastRow = sheet.getLastRowNum(); 
 
			HSSFRow row = null; 
			HSSFCell cell = null; 
			int columnNum = row.getLastCellNum(); 
			String data[] = new String[2]; 
 
			// 读取Excel表格 
			for (int i = 1; i <= lastRow; i++) { // 行循环 
				row = sheet.getRow(i); 
 
				for (int j = 0; j < columnNum; j++) { // 列循环 
					cell = row.getCell((short) j); 
					if (cell != null 
							&& cell.getCellType() != HSSFCell.CELL_TYPE_BLANK) { 
						data[j] = cell.getStringCellValue().trim(); 
 
					} 
				} 
 
				// TODO add to List 
			} 
 
		} catch (FileNotFoundException e) { 
			log.error(e); 
		} catch (IOException e) { 
			log.error(e); 
		} 
 
		return arrayList; 
 
	} 
 
	public void writeToExcel(Map map, File outFile) throws IOException { 
		if (map == null) { 
			log.info("没有输出到excel的数据！"); 
			return; 
		} 
		HSSFWorkbook wb = new HSSFWorkbook(); 
		HSSFSheet sheet = wb.createSheet(); 
 
		// 标题 
		HSSFRow title = sheet.createRow(0); 
		HSSFCell userCell = title.createCell((short) 0), staffCell = title 
				.createCell((short) 1), _infoCell = title.createCell((short) 2); 
		userCell.setEncoding(HSSFCell.ENCODING_UTF_16); 
		userCell.setCellValue("后台用户"); 
		staffCell.setEncoding(HSSFCell.ENCODING_UTF_16); 
		staffCell.setCellValue("柜员号"); 
		_infoCell.setEncoding(HSSFCell.ENCODING_UTF_16); 
		_infoCell.setCellValue("失败原因"); 
 
		for (Iterator itr = map.keySet().iterator(); itr.hasNext();) { 
			String key = (String) itr.next(); 
			List list = (List) map.get(key); 
			String info = ""; 
			if ("1".equals(key)) 
				info = "后台用户不存在"; 
			else if ("2".equals(key)) 
				info = "柜员号重复"; 
			else if ("3".equals(key)) 
				info = "插入数据库出错"; 
 
			appendToSheet(sheet, list, info); 
		} 
 
		FileOutputStream fos = new FileOutputStream(outFile); 
 
		wb.write(fos); 
		fos.close(); 
 
	} 
 
	private void appendToSheet(HSSFSheet sheet, List datas, String info) { 
 
		if (datas == null) 
			return; 
		int offset = sheet.getLastRowNum(); 
		int size = datas.size(); 
		for (int i = 0; i < size; i++) { 
			LoginIdStaffNo ls = (LoginIdStaffNo) datas.get(i); 
			HSSFRow row = sheet.createRow(offset + i + 1); 
			row.createCell((short) 0).setCellValue(ls.getUserLoginId()); 
			row.createCell((short) 1).setCellValue(ls.getStaffNo()); 
 
			HSSFCell infoCell = row.createCell((short) 2); 
			infoCell.setEncoding(HSSFCell.ENCODING_UTF_16); 
			infoCell.setCellValue(info); 
		} 
	} 
}