POI下载excel

Posted 2022-11-22 z_java_20150812

后台代码：

/**
	 * 下载汇总
	 * @param request
	 * @param map
	 * @return
	 */
	@RequestMapping(value = "excel")
	public String excel(HttpServletRequest request, HttpServletResponse response, ModelMap map) 
		String template_id = CmnUtFunc.nvl(request.getParameter("template_id"));
		DataCenterTemplate dataCenterTemplate = companyDataManageService.getTemplateById(template_id);
		String path = dataCenterTemplate.getTemplatePath(); // 模板文件在服务器端的存放路径
		
		File file = new File(path);
		Map<String, List<String>> oriSheetMap = ExcelUtil.getExcelInfo(file);
		
		List<Map<Integer, List<Integer>>> gatherList = ExcelUtil.getGatherInfo(file);
		List<List<Map>> exportList = new ArrayList<List<Map>>();
		for(Entry<String, List<String>> entry : oriSheetMap.entrySet())
			String sheet_name = entry.getKey();
			List<Map> sheetList = dataReportUploadService.getGatherList(template_id, sheet_name);
			exportList.add(sheetList);
		
		
		this.exportData(gatherList, exportList, file, request, response);
		
		return "dataReport/toExcel.jsp";
	
	
	/**
	 * 数据导出
	 */
	private void exportData(List<Map<Integer, List<Integer>>> gatherList, List<List<Map>> exportList, File file, HttpServletRequest request, HttpServletResponse response)
		String template_id = CmnUtFunc.nvl(request.getParameter("template_id"));
		DataCenterTemplate dataCenterTemplate = companyDataManageService.getTemplateById(template_id);
		String template_name = dataCenterTemplate.getTemplateName();
		
		Workbook workbook = null;
		Sheet sheet=null;
		try 
			//创建对象
			String strExcelName = file.getAbsolutePath();
			String fileType = String.valueOf(strExcelName.substring(strExcelName.lastIndexOf(".") + 1));
			if ("xls".equals(fileType)) 
				workbook = new HSSFWorkbook(new FileInputStream(file));
			else if ("xlsx".equals(fileType)) 
				workbook = new XSSFWorkbook(new FileInputStream(file));
			
			
			for (int i = 0, index2 = 0; i < workbook.getNumberOfSheets(); i++)  //获取每个Sheet表
				sheet = workbook.getSheetAt(i);
				
				String sheet_name = sheet.getSheetName();
				if (sheet_name.indexOf(DataReportConstance.SHEET_NO_READ) >= 0) 
					continue;
				
				
				if (sheet.getLastRowNum() == 0 &&  sheet.getPhysicalNumberOfRows() == 0) 
					continue;
				
				
				List<Map> sheetList = exportList.get(index2); // 导出数据
				
				/**
				 * 有合计行：删掉标题行和合计行之间的行，从标题行开始插入行写数据，设置求和公式
				 * 无合计行：删掉标题行之后的行，从标题行+1开始写数据
				 */
				boolean flag = false;
				int begin_index = ExcelUtil.X;
				int endRow = 0;
				List<Integer> tList = new ArrayList<Integer>();
				for (Entry<Integer, List<Integer>> entry : gatherList.get(index2).entrySet()) 
					endRow = entry.getKey();
					tList = entry.getValue();
					if (tList.size() > 0) 
						flag = true;
					
				
				
				Row titleRow = sheet.getRow(ExcelUtil.X-1); 
				int col_count = titleRow.getPhysicalNumberOfCells();
				
				// 使用模板文件中单元格的样式
				List<CellStyle> stList = new ArrayList<CellStyle>();
				Row stRow = sheet.getRow(begin_index);
				if (stRow != null) 
					for (int k = ExcelUtil.Y-1; k < col_count+(ExcelUtil.Y-1); k++) 
						if (stRow.getCell(k) != null) 
							stList.add(stRow.getCell(k).getCellStyle());
						 else 
							stList.add(null);
						
					
				
				
				for (int j = 0; j < sheetList.size(); j++) 
					Map<String, String> map = sheetList.get(j);
					
					sheet.shiftRows(begin_index, sheet.getLastRowNum(),1,true,false); // begin_index到 sheet.getLastRowNum()行，下移
					
	                Row row = sheet.createRow(begin_index);
	                if (stRow != null) 
	                	row.setHeight(stRow.getHeight()); // 设置行高
	                
					int index = 1;
					for (int k = ExcelUtil.Y-1; k < col_count+(ExcelUtil.Y-1); k++)  
						Cell cell = row.createCell(k);
						if (flag && tList.contains(k)) 
							cell.setCellValue(Double.parseDouble(map.get("DATE_A"+index) == null ? "0" : map.get("DATE_A"+index)));
						 else 
							cell.setCellValue(map.get("DATE_A"+index));
						
						if (stRow != null && stList.size() > index-1 &&stList.get(index-1) != null) 
							cell.setCellStyle(stList.get(index-1));
						
						index++;
					
					begin_index++;
				
				
				for (int j = ExcelUtil.X+1; j < endRow+1; j++) 
					sheet.shiftRows(ExcelUtil.X+1+sheetList.size(), sheet.getLastRowNum()+1, -1,true,false); // 删除模板文件中的示例数据行 ，示例数据行下方，整行上移
				
				
				if (flag) 
					Row totalRow = sheet.getRow(ExcelUtil.X + sheetList.size());
					for (int j = 0; j < tList.size(); j++) 
						String colString = CellReference.convertNumToColString(tList.get(j));  //长度转成ABC列
						String sumstring = "SUM(" + colString + (ExcelUtil.X +1) + ":" + colString + (sheetList.size()+ ExcelUtil.X) + ")"; // 求和公式
						totalRow.getCell(tList.get(j)).setCellFormula(sumstring);
					
				
				
				index2++;
			
			
			String filePath = DataReportConstance.B2B_DATAREPORT_EXPORT_PATH;
			String fileName = template_name + "汇总" + "." + fileType;

			File filepath = new File(filePath);
            if (!filepath.exists()) 
            	filepath.mkdirs();
            
            
			request.setAttribute("filePath",filePath);
			request.setAttribute("fileName",fileName);
			
			FileOutputStream fileOut = new FileOutputStream(filePath+fileName);
			workbook.write(fileOut);
			fileOut.close();
		 catch (Exception e) 
			// TODO: handle exception
			e.printStackTrace();
		
	

前台代码：

<%@page import="java.net.URLEncoder"%>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ include file="/common/lib/taglibs.jsp"%>
<%@ page import="java.io.*" %>
<%
  String  fileName = (String)request.getAttribute("fileName");
  String  filePath = (String)request.getAttribute("filePath");
  FileInputStream inStream=new FileInputStream(filePath + fileName);
  
  String  realFileName = CmnUtFunc.nvl(request.getAttribute("realFileName"));
  if(!"".equals(realFileName))
	  fileName = realFileName;
  
  
  //设置输出的格式 
    response.reset(); 
    response.setContentType("bin");
    response.addHeader("Content-Disposition","attachment; filename=\\"" + URLEncoder.encode(fileName, "UTF-8") + "\\"");
    response.setHeader("Content-Length", String.valueOf(inStream.getChannel().size())); // 如果没有此行代码，打开excel文件时，会提示“发现不可读取的内容，是否继续”
  //循环取出流中的数据 
    byte[] b = new byte[1024]; 
    int len; 
    while((len=inStream.read(b)) >0) 
    	response.getOutputStream().write(b,0,len);  
    inStream.close(); 
%>