ExcelUtil

package cn.com.jansh.core.util;

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;

import org.springframework.web.multipart.MultipartFile;

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.ArrayList;

import java.util.List;

/**

 * Excel处理

 * @author duanmuyn

 *

 */

public class ExcelUtil {

    // 对外提供读取excel文件的接口

    public static List<List<Object>> readExcel(MultipartFile myfile)throws IOException {

        String extension = (myfile.getOriginalFilename().lastIndexOf(".") == -1) ? "": myfile.getOriginalFilename().substring(myfile.getOriginalFilename().lastIndexOf(".") + 1);

        if ("xls".equals(extension)) { // 2003

//            System.err.println("读取excel2003文件内容");

            return read2003Excel(myfile.getInputStream());

        } else if ("xlsx".equals(extension)) { // 2007

//            System.err.println("读取excel2007文件内容");

            return read2007Excel(myfile.getInputStream());

        } else {

            throw new IOException("不支持的文件类型:" + extension);

        }

    }

   /**

    * 读取2003excel

    * @param file

    * @return

    */

    private static List<List<Object>> read2003Excel(InputStream inputStream)

        throws IOException {

        List<List<Object>> dataList = new ArrayList<List<Object>>();

        HSSFWorkbook wb = new HSSFWorkbook(inputStream);

        HSSFSheet sheet = wb.getSheetAt(0);

        HSSFRow row = null;

        HSSFCell cell = null;

        Object val = null;

        DecimalFormat df = new DecimalFormat("0");// 格式化数字

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");// 格式化日期字符串

        for (int i = sheet.getFirstRowNum(); i < sheet.getPhysicalNumberOfRows(); i++) {

            row = sheet.getRow(i);

            if (row == null) {

                continue;

            }

            List<Object> objList = new ArrayList<Object>();

            for (int j = row.getFirstCellNum(); j < row.getLastCellNum();j++) {

                cell = row.getCell(j);

                if (cell == null) {

                    val = null;

                    objList.add(val);

                    continue;

                }

                switch (cell.getCellType()) {

                case HSSFCell.CELL_TYPE_STRING:

                    val = cell.getStringCellValue();

                    break;

                case HSSFCell.CELL_TYPE_NUMERIC:

                    if ("@".equals(cell.getCellStyle().getDataFormatString())) {

                        val = df.format(cell.getNumericCellValue());

                    } else if ("General".equals(cell.getCellStyle() .getDataFormatString())) {

                        val = df.format(cell.getNumericCellValue());

                    } else {

                        val = sdf.format(HSSFDateUtil.getJavaDate(cell.getNumericCellValue()));

                    }

                    break;

                case HSSFCell.CELL_TYPE_BOOLEAN:

                    val = cell.getBooleanCellValue();

                    break;

                case HSSFCell.CELL_TYPE_BLANK:

                    val = "";

                    break;

                default:

                    val = cell.toString();

                    break;

                }

                objList.add(val);

            }

            dataList.add(objList);

        }

        return dataList;

    }

   /**

    * 读取excel表头

    * @param file

    * @return

    * @throws IOException

    */

    public static String[] readExcelHead(File file) throws IOException {

        HSSFWorkbook wb = new HSSFWorkbook(new FileInputStream(file));

        HSSFSheet sheet = wb.getSheetAt(0);

        HSSFRow row = null;

        HSSFCell cell = null;

        row = sheet.getRow(0);

        String[] buff = new String[row.getLastCellNum()];

        for (int i = row.getFirstCellNum(); i < row.getLastCellNum(); i++) {

            cell = row.getCell(i);

            buff[i] = cell.getStringCellValue();

        }

        return buff;

    }

    /**

    * 读取2007excel

    *

    * @param file

    * @return

    */

    private static List<List<Object>> read2007Excel(InputStream inputStream)

        throws IOException {

        List<List<Object>> dataList = new ArrayList<List<Object>>();

        XSSFWorkbook xwb = new XSSFWorkbook(inputStream);

        XSSFSheet sheet = xwb.getSheetAt(0);

        XSSFRow row = null;

        XSSFCell cell = null;

        Object val = null;

        DecimalFormat df = new DecimalFormat("0");// 格式化数字

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");// 格式化日期字符串

        for (int i = sheet.getFirstRowNum();i < sheet.getPhysicalNumberOfRows(); i++) {

            row = sheet.getRow(i);

            if (row == null) {

                continue;

            }

            List<Object> objList = new ArrayList<Object>();

            for (int j = row.getFirstCellNum(); j < row.getLastCellNum();j++) {

                cell = row.getCell(j);

                if (cell == null) {

                    val = null;

                    objList.add(val);

                    continue;

                }

                switch (cell.getCellType()) {

                case XSSFCell.CELL_TYPE_STRING:

                    val = cell.getStringCellValue();

                    break;

                case XSSFCell.CELL_TYPE_NUMERIC:

                    if ("@".equals(cell.getCellStyle().getDataFormatString())) {

                        val = df.format(cell.getNumericCellValue());

                    } else if ("General".equals(cell.getCellStyle().getDataFormatString())) {

                        val = df.format(cell.getNumericCellValue());

                    } else {

                        val = sdf.format(HSSFDateUtil.getJavaDate(cell.getNumericCellValue()));

                    }

                    break;

                case XSSFCell.CELL_TYPE_BOOLEAN:

                    val = cell.getBooleanCellValue();

                    break;

                case XSSFCell.CELL_TYPE_BLANK:

                    val = "";

                    break;

                default:

                    val = cell.toString();

                    break;

                }

                objList.add(val);

            }

            dataList.add(objList);

        }

        return dataList;

    }

    /*

    将excel的第一个表单第一行的第一个单元格的值写成“a test”。

POIFSFileSystem fs =new POIFSFileSystem(new FileInputStream(“workbook.xls”));

HSSFWorkbook wb = new HSSFWorkbook(fs);

HSSFSheet sheet = wb.getSheetAt(0);

HSSFRow row = sheet.getRow(0);

HSSFCell cell = row.getCell((short)0);

cell.setCellValue("a test");

// Write the output to a file

FileOutputStream fileOut = new FileOutputStream("workbook.xls");

wb.write(fileOut);

fileOut.close();

*/

}