poi读Excle

 项目中用到的工具类

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.LinkedList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.myfaces.custom.fileupload.UploadedFile;
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;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class ReadExcel {
	public static Log log = LogFactory.getLog(ReadExcel.class);

	/**
	 * @param File to read
	 * @return 二维List，List元素为行，List长度为所读文件行数-1(去除第一行(表头))
	 * @exception IOException 当文件名为xls、xlsx以外时抛出该异常
	 * */
	public static List<List<Object>> readExcel(File file) throws IOException {
		String fileName = file.getName();
		String extension = fileName.lastIndexOf(".") == -1 ? "" : fileName.substring(fileName.lastIndexOf(".") + 1);
		if ("xls".equals(extension)) {
			return read2003Excel(new FileInputStream(file));
		} else if ("xlsx".equals(extension)) {
			return read2007Excel(new FileInputStream(file));
		} else {
			throw new IOException("不支持的文件类型");
		}
	}
	
	public static List<List<Object>> readExcel(UploadedFile file) throws IOException {
		String fileName = file.getName();
		String extension = fileName.lastIndexOf(".") == -1 ? "" : fileName.substring(fileName.lastIndexOf(".") + 1);
		if ("xls".equals(extension)) {
			return read2003Excel(file.getInputStream());
		} else if ("xlsx".equals(extension)) {
			return read2007Excel(file.getInputStream());
		} else {
			throw new IOException("不支持的文件类型");
		}
	}

	/*
	 * 读取 office 2003 excel
	 * 
	 * @throws IOException
	 * 
	 * @throws FileNotFoundException
	 */
	private static List<List<Object>> read2003Excel(InputStream file)
			throws IOException {
		List<List<Object>> list = new LinkedList<List<Object>>();
		HSSFWorkbook hwb = new HSSFWorkbook(file);
		HSSFSheet sheet = hwb.getSheetAt(0);
		Object value = null;
		HSSFRow row = null;
		HSSFCell cell = null;
        HSSFRow firstRow=sheet.getRow(sheet.getFirstRowNum());
		for (int i = sheet.getFirstRowNum()+1; i < sheet
				.getPhysicalNumberOfRows(); i++) {
			row = sheet.getRow(i);
			if (row == null) {
				continue;
			}
			List<Object> linked = new LinkedList<Object>();
			for (int j = 0; j < firstRow.getLastCellNum(); j++) {
				cell = row.getCell(j);
				if (cell == null) {
                    value="";
                    linked.add(value);
					continue;
				}
				DecimalFormat df = new DecimalFormat("0");// 格式化 number String
															// 字符
				SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");// 格式化日期字符串
				DecimalFormat nf = new DecimalFormat("0");// 格式化数字
				switch (cell.getCellType()) {
				case XSSFCell.CELL_TYPE_STRING:
					log.info(i + "行" + j + " 列 is String type");
					value = cell.getStringCellValue();
					break;
				case XSSFCell.CELL_TYPE_NUMERIC:
					log.info(i + "行" + j+ " 列 is Number type ; DateFormt:"+ cell.getCellStyle().getDataFormatString());
					if ("@".equals(cell.getCellStyle().getDataFormatString())) {
						value = df.format(cell.getNumericCellValue());
					} else if ("General".equals(cell.getCellStyle().getDataFormatString())) {
						value = nf.format(cell.getNumericCellValue());
					} else {
						value = sdf.format(HSSFDateUtil.getJavaDate(cell.getNumericCellValue()));
					}
					break;
				case XSSFCell.CELL_TYPE_BOOLEAN:
					log.info(i + "行" + j + " 列 is Boolean type");
					value = cell.getBooleanCellValue();
					break;
				case XSSFCell.CELL_TYPE_BLANK:
					log.info(i + "行" + j + " 列 is Blank type");
					value = "";
					break;
				default:
					log.info(i + "行" + j + " 列 is default type");
					value = cell.toString();
				}
				if (value == null || "".equals(value)) {
					value="";
				}
				linked.add(value);

			}
			list.add(linked);
		}

		return list;
	}

	/*
	 * 读取Office 2007 excel
	 */

	private static List<List<Object>> read2007Excel(InputStream file)
			throws IOException {

		List<List<Object>> list = new LinkedList<List<Object>>();
		// 构造 XSSFWorkbook 对象，strPath 传入文件路径
		XSSFWorkbook xwb = new XSSFWorkbook(file);
		// 读取第一章表格内容
		XSSFSheet sheet = xwb.getSheetAt(0);
		Object value = null;
		XSSFRow row = null;
		XSSFCell cell = null;
		XSSFRow firstRow = sheet.getRow(sheet.getFirstRowNum());
		for (int i = sheet.getFirstRowNum()+1; i < sheet
				.getPhysicalNumberOfRows(); i++) {
			row = sheet.getRow(i);
			if (row == null) {
				continue;
			}
			List<Object> linked = new LinkedList<Object>();
			for (int j = 0; j < firstRow.getLastCellNum(); j++) {
				cell = row.getCell(j);
				if (cell == null) {
					value="";
					linked.add(value);
					continue;
				}
				DecimalFormat df = new DecimalFormat("0");// 格式化 number String
															// 字符
				SimpleDateFormat sdf = new SimpleDateFormat(
						"yyyy-MM-dd HH:mm:ss");// 格式化日期字符串
				DecimalFormat nf = new DecimalFormat("0");// 格式化数字

				switch (cell.getCellType()) {
				case XSSFCell.CELL_TYPE_STRING:
					log.info(i + "行" + j + " 列 is String type");
					value = cell.getStringCellValue();
					break;
				case XSSFCell.CELL_TYPE_NUMERIC:
					log.info(i + "行" + j
							+ " 列 is Number type ; DateFormt:"
							+ cell.getCellStyle().getDataFormatString());
					if ("@".equals(cell.getCellStyle().getDataFormatString())) {
						value = df.format(cell.getNumericCellValue());
					} else if ("General".equals(cell.getCellStyle()
							.getDataFormatString())) {
						value = nf.format(cell.getNumericCellValue());
					} else {
						value = sdf.format(HSSFDateUtil.getJavaDate(cell
								.getNumericCellValue()));
					}
					break;
				case XSSFCell.CELL_TYPE_BOOLEAN:
					log.info(i + "行" + j + " 列 is Boolean type");
					value = cell.getBooleanCellValue();
					break;
				case XSSFCell.CELL_TYPE_BLANK:
					log.info(i + "行" + j + " 列 is Blank type");
					value = "";
					break;
				default:
					log.info(i + "行" + j + " 列 is default type");
					value = cell.toString();
				}
				if (value == null || "".equals(value)) {
					value = "";
				}
				linked.add(value);
			}
			list.add(linked);
		}
		return list;
	}
/*	public static void main(String args[]) throws IOException{
		List<List<Object>> list = readExcel(new File("D://test2.xlsx"));
		for (List<Object> list1 : list) {
			System.out.println(list1);
		}
	}*/

}