java 导出excel，自己研究去吧！

http://blog.csdn.net/cmtobby/article/details/1508647
http://blog.csdn.net/evangel_z/article/details/7332535


这里曾涉及到一个问题，在导出excel表格的时候如何弹出下载提示框并修改下载文件名称，解决方案见下文：

http://wenku.baidu.com/link?url=PdTPKaJC3ykNR9mQDYBOxbsxq2NIPtoKokT1-IThGpUgvvbPLLJrIlpxv1QDC0ygkAC_H_onvB0kaX5Iz7zwCkuve2YydOUggjlCtducRxi



曾经自己写的一个导出excel的方法：

	public String createExcel() {
		if (null == channelid) {
			yAllChannelSummary = true;
		}
		String filePath = ServletActionContext.getServletContext().getRealPath(File.separator) + "excel"+File.separator;
		File excelFile = new File(filePath);
		// 删除临时目录下的excel文件
		this.deleteFile(excelFile);
		if (!excelFile.isDirectory()) {
			excelFile.mkdirs();
		}
		List<Mall3AdSummary> summaryList = new ArrayList<Mall3AdSummary>();
		List<TreeMap<Integer,Mall3AdSummary>> summaryMapList = new ArrayList<TreeMap<Integer,Mall3AdSummary>>();
		if (!yAllChannelSummary) {// 非渠道全部查询
			summaryList = mall3AdSummaryManager.getList(channelid, startime, endtime, type, -1, -1, null, null);// 获得导出记录
		} else {// 渠道全部查询
			summaryList = mall3AdSummaryManager.getNoChannelList(startime, endtime, type, -1, -1, null, null);
			for (int i = 0; i < summaryList.size(); i++) {// 循环获取每条汇总数据下面每个渠道的详细数据
				Mall3AdSummary mall = summaryList.get(i);
				TreeMap<Integer,Mall3AdSummary> map = new TreeMap<Integer,Mall3AdSummary>();
				map.put(0, mall);// 第一条为汇总数据，后面的是渠道详细数据
				/////////////////////////////////////////////////////////////////////////////////////////////////////
				List<Mall3AdSummary> channDetail = new ArrayList<Mall3AdSummary>();
				channDetail = mall3AdSummaryManager.getNoChannelListDetail(mall.getChecktime(), null == mall.getCheckhour() ? null : String.valueOf(mall.getCheckhour()), type, -1, -1, null, null);
				for (int j = 0; j < channDetail.size(); j++) {
					map.put(j+1, channDetail.get(j));
				}
				summaryMapList.add(map);
			}
		}
		if (null == channelid) {
			yAllChannelSummary = true;
		}
		DecimalFormat df = new DecimalFormat("0.00");//格式化小数，不足的补0
		HSSFWorkbook wb = new HSSFWorkbook();
		
		// 汇总数据
		allAdSummary = mall3AdSummaryManager.getAllListAdd(channelid, startime, endtime, type);
		allAdSummary.setActiveretio(df.format(Double.parseDouble(allAdSummary.getActiveretio())*100));
		
		HandleExcel handleExcel = new HandleExcel();
		if (!yAllChannelSummary) {// 非渠道全部查询
			handleExcel.createExcel(wb, summaryList, type, yAllChannelSummary, allAdSummary);// 创建excel表格数据
		} else {// 渠道全部查询
			handleExcel.createExcelAsNoChannel(wb, summaryMapList, type, allAdSummary);
		}
		FileOutputStream fos = null;
		try {
			if(null == summaryList || summaryList.size() == 0){
				ServletActionContext.getResponse().getWriter().println("<script>alert('没有数据可供导出');location.href='/app30/mall3adsummary.action?type=1'</script>");
				return null;
			}
			ServletActionContext.getRequest().setCharacterEncoding("UTF-8");

			String filename = new SimpleDateFormat("yyyymmddhhmmss").format(new Date())+".xls";
			fos = new FileOutputStream(new File(filePath + filename),false);
			//ServletActionContext.getResponse().sendRedirect("excel/"+filename);
			wb.write(fos);
			ServletActionContext.getResponse().reset();//清空response的buffer
			ServletActionContext.getResponse().setContentType("application/vnd.ms-excel");//设置正确的输出类型
			
			ServletActionContext.getRequest().getContentType();
			// PrintWriter out = ServletActionContext.getResponse().getWriter(); 
			
			FileInputStream fis = new FileInputStream(
					new File(filePath + filename));
			OutputStream os = ServletActionContext.getResponse().getOutputStream();

			String fileName = "jifenqiang-" + new SimpleDateFormat("yyyyMMddhhmmss").format(new Date()) + ".xls";
			ServletActionContext.getResponse().setHeader("Content-Disposition", "attachment;filename="
					+ new String(fileName.getBytes("gb2312"), "iso8859-1"));

			ServletActionContext.getResponse().setCharacterEncoding("utf-8");
			int j = 0;
			byte[] b = new byte[8192];
			while ((j = fis.read(b, 0, 8192)) != -1) {
				os.write(b, 0, j);
			}
			os.flush();
			fis.close();
			
			// ServletActionContext.getRequest().getRequestDispatcher("/excel/"+filename).forward(ServletActionContext.getRequest(), ServletActionContext.getResponse());
			// out.print("<a href='"+filePath+new SimpleDateFormat("yyyymmddhhmmss").format(new Date())+".xls' target='blank' >"+"下载"+title+"</a>"+"(右键单击另存为)");
			fos.close();
			return null;
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
		//exportExcel.outputExcel(filePath);
	}

这里面最重要的是下载提示框和修改下载文件的名称这一块的解决方案。

下面是标准的下载提示框和修改下载文件的名称的servlet示例：

package com.lwf.poi;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class TestUpload extends HttpServlet {
	@Override
	protected void doGet(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		FileInputStream fis = new FileInputStream(
				new File("C:/ererer.xlsx"));
		OutputStream os = response.getOutputStream();

		String fileName = "20160721.xlsx";
		response.setHeader("Content-Disposition", "attachment;filename="
				+ new String(fileName.getBytes("gb2312"), "iso8859-1"));

		response.setCharacterEncoding("utf-8");
		int j = 0;
		byte[] b = new byte[8192];
		while ((j = fis.read(b, 0, 8192)) != -1) {
			os.write(b, 0, j);
		}
		os.flush();
		fis.close();
	}

	@Override
	protected void doPost(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}
}