将数据库中数据导出为excel表格

小灰灰 2021-04-13 16:38 768阅读 0赞

public class Excel {
    
        private static Logger logger = LoggerFactory.getLogger(Excel.class);
    
        /**
         * 导出项目列表
         *
         * @param jsonArray
         * @param request
         * @param response
         * @return
         */
        public static Result createCloudServerXls(JSONArray jsonArray, HttpServletRequest request, HttpServletResponse response) {
            try {
                // 创建HSSFWorkbook
                String sheetName = "报表导出";
                //表头，根据自己需求更改
                String[] cellTitle = new String[]{"学号","姓名","年龄","班级"};
                String[][] rows = null;
                List<Student> list = JSONArray.parseArray(jsonArray.toJSONString(), Student.class);
                if (!ListTool.isEmpty(list)) {
                    rows = new String[list.size()][4];
                    for (int i = 0; i < list.size(); i++) {
                        Student student = list.get(i);
                        rows[i][0] = student.getSno();
                        rows[i][1] = student.getName();
                        rows[i][2] = student.getAge();
                        rows[i][3] = student.getGrade()
                    }
                } else {
                    rows = new String[0][4];
                }
                HSSFWorkbook workbook = getHSSFWorkbook(sheetName, cellTitle, rows, null);
                // 下载表格到浏览器
                response.setCharacterEncoding("utf-8");
                response.setContentType("application/octet-stream");
                String fileName = sheetName + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + ".xls";
                final String userAgent = request.getHeader("user-agent").toLowerCase();
                if (userAgent.contains("trident") || userAgent.contains("edge")) {
                    fileName = URLEncoder.encode(fileName, "UTF-8");
                } else {
                    fileName = new String(fileName.getBytes("utf-8"), "iso-8859-1");
                }
                response.setHeader("Content-Disposition", "attachment;fileName=" + fileName);
                OutputStream os = response.getOutputStream();
                workbook.write(os);
                os.flush();
                os.close();
            } catch (Exception e) {
                logger.error("生成文档失败", e);
                return new Result(false, "发生异常生成文档失败");
            }
            return new Result(true, "生成文档成功");
        }
    
        /**
         * 导出Excel
         *
         * @param sheetName sheet名称
         * @param title     标题
         * @param values    内容
         * @param wb        HSSFWorkbook对象
         * @return
         */
        private static HSSFWorkbook getHSSFWorkbook(String sheetName, String[] title, String[][] values, HSSFWorkbook wb) {
            // 第一步，创建一个HSSFWorkbook，对应一个Excel文件
            if (wb == null) {
                wb = new HSSFWorkbook();
            }
            // 第二步，在workbook中添加一个sheet,对应Excel文件中的sheet
            HSSFSheet sheet = wb.createSheet(sheetName);
            // 第三步，在sheet中添加表头第0行,注意老版本poi对Excel的行数列数有限制
            HSSFRow row = sheet.createRow(0);
            // 第四步，创建单元格，并设置值表头 设置表头居中
            HSSFCellStyle style = wb.createCellStyle();
            style.setAlignment(HorizontalAlignment.CENTER); // 创建一个居中格式
            // 声明列对象
            HSSFCell cell = null;
            // 创建标题
            for (int i = 0; i < title.length; i++) {
                cell = row.createCell(i);
                cell.setCellValue(title[i]);
                cell.setCellStyle(style);
            }
            // 创建内容
            for (int i = 0; i < values.length; i++) {
                row = sheet.createRow(i + 1);
                for (int j = 0; j < values[i].length; j++) {
                    // 将内容按顺序赋给对应的列对象
                    row.createCell(j).setCellValue(values[i][j]);
                }
            }
            return wb;
        }
    }