导出Excel功能实现

Controller逻辑分析

在实际工作中，常需要将数据库中的数据导出为Excel文件。以下是实现导出功能的Controller逻辑说明：

@RequestMapping(value = {"/ledger_fdi_reinvest_rpt_load"}, method = RequestMethod.POST)@ResponseBodypublic void downLoadExcel(Page page, HttpServletRequest request, HttpServletResponse response) throws Exception {    page.setPageSize(Integer.MAX_VALUE);    page.setPageNo(1);    QueryFilter queryFilter = new QueryFilter();    //级联查询目前只支持EQFilter 一级级联    String innerCorpName = request.getParameter("innerCorpName");    if (StringUtils.isNotEmpty(innerCorpName)) {        queryFilter.setLikeFilter("innerCorpName", innerCorpName);    }    String outCorpName = request.getParameter("outCorpName");    if (StringUtils.isNotEmpty(outCorpName)) {        queryFilter.setLikeFilter("outCorpName", outCorpName);    }    String outCnyCde = request.getParameter("outCnyCde");    if (StringUtils.isNotEmpty(outCnyCde)) {        queryFilter.setEQFilter("cnyCde.cnyCde", outCnyCde);    }    String vocCatCde = request.getParameter("vocCatCde");    if (StringUtils.isNotEmpty(vocCatCde)) {        queryFilter.setEQFilter("vocCde.vocCatCde.vocCde", vocCatCde);    }    String outVocCde = request.getParameter("outVocCde");    if (StringUtils.isNotEmpty(outVocCde)) {        queryFilter.setEQFilter("vocCde.vocCde", outVocCde);    }    String rptYear = request.getParameter("rptYear");    if (StringUtils.isNotEmpty(rptYear)) {        queryFilter.setEQFilter("rptYear", rptYear);    }    page.setOrder("desc");    page.setOrderBy("rptYear");    Page
   
     pages = this.commonService.findSupportCascade(page, queryFilter.getPropertyFilters(), LedgerFdiReinvestRptTab.class);    getdownLoadDatas(pages.getResult(), request, response);}

Excel生成工具类细节

在项目中，为了实现Excel导出功能，我们使用了ExcelUtil工具类。以下是工具类的主要实现逻辑：

public class ExcelUtil {    private ExcelUtil() {}        public static void exportExcel(String sheetName, String title, int fontHeight, String[] headName, List
    
     > list, int listSize, String[] headCode, String fileName, HttpServletRequest request, HttpServletResponse response) {        try {            HSSFWorkbook wb = new HSSFWorkbook();            HSSFCellStyle styleForTitle = wb.createCellStyle();            styleForTitle.setAlignment(HSSFCellStyle.ALIGN_CENTER);            styleForTitle.setFillForegroundColor(HSSFColor.WHITE.index);            styleForTitle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);                        HSSFFont fontForTitle = wb.createFont();            fontForTitle.setColor(HSSFColor.BLACK.index);            fontForTitle.setFontHeightInPoints((short) 16);            fontForTitle.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);            styleForTitle.setFont(fontForTitle);                        HSSFCellStyle styleForHead = wb.createCellStyle();            styleForHead.setAlignment(HSSFCellStyle.ALIGN_CENTER);            styleForHead.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);            styleForHead.setFillForegroundColor(HSSFColor.WHITE.index);            styleForHead.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);            styleForHead.setBorderBottom(HSSFCellStyle.BORDER_THIN);            styleForHead.setBorderLeft(HSSFCellStyle.BORDER_THIN);            styleForHead.setBorderRight(HSSFCellStyle.BORDER_THIN);            styleForHead.setBorderTop(HSSFCellStyle.BORDER_THIN);                        HSSFFont fontForHead = wb.createFont();            fontForHead.setColor(HSSFColor.BLACK.index);            fontForHead.setFontHeightInPoints((short) 12);            fontForHead.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);            styleForHead.setFont(fontForHead);                        HSSFCellStyle styleForContent = wb.createCellStyle();            styleForContent.setAlignment(HSSFCellStyle.ALIGN_LEFT);            styleForContent.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);            styleForContent.setFillForegroundColor(HSSFColor.WHITE.index);            styleForContent.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);            styleForContent.setWrapText(true);                        HSSFFont fontForContent = wb.createFont();            fontForContent.setFontHeightInPoints((short) 11);            fontForContent.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);            styleForContent.setFont(fontForContent);                        Row row = sheet.createRow(0);            for (int i = 0; i < headName.length; i++) {                row.createCell(i);            }                        sheet.addMergedRegion(new CellRangeAddress(0, 0, 0, headName.length - 1));            Cell cellMerged = row.getCell(0);            cellMerged.setCellStyle(styleForTitle);            cellMerged.setCellType(HSSFCell.CELL_TYPE_STRING);            cellMerged.setCellValue(title);                        row = sheet.createRow(1);            for (int k = 0; k < headName.length; k++) {                cell = row.createCell(k);                cell.setCellValue(headName[k]);                cell.setCellStyle(styleForHead);            }                        for (int i = 0; i < listSize; i++) {                if (list.get(i) != null) {                    Row row = sheet.createRow(i + 2);                    Map
     
       hmTemp = list.get(i);                    String data = "";                                        for (int j = 0; j < headName.length; j++) {                        data = hmTemp.get(headName[j]) == null ? "" : hmTemp.get(headName[j]).toString();                        Cell ce = row.createCell(j + 1);                        ce.setCellValue(data);                        ce.setCellStyle(styleForContent);                    }                }            }                        response.reset();            response.addHeader("Content-Disposition", "attachment;filename=\"" + fileName + "\"");            response.setContentType("application/vnd.ms-excel;charset=utf-8");            OutputStream toClient = new BufferedOutputStream(response.getOutputStream());            wb.write(toClient);            toClient.flush();            toClient.close();        } catch (IOException ex) {            ex.printStackTrace();        }    }}