POI方式实现Excel表格数据导出

 1         <!-- office 操作工具 -->
 2         <dependency>
 3             <groupId>org.apache.poi</groupId>
 4             <artifactId>poi</artifactId>
 5             <version>3.17</version>
 6         </dependency>
 7         <dependency>
 8             <groupId>org.apache.poi</groupId>
 9             <artifactId>poi-ooxml</artifactId>
10             <version>3.17</version>
11         </dependency>
12 
13         <dependency>
14             <groupId>org.apache.poi</groupId>
15             <artifactId>poi-scratchpad</artifactId>
16             <version>3.17</version>
17         </dependency>

 1 public class MyExcelUtils {
 2     /**
 3      * @param titles  表头
 4      * @param out
 5      * @param listMap 数据
 6      * @param keys    数据库字段（与表头相对应）
 7      */
 8     public static void export(String[] titles, ServletOutputStream out, List<Map<String, Object>> listMap, String[] keys) {
 9         try {
10             //1.创建一个workbook，对应一个Excel文件
11             HSSFWorkbook workbook = new HSSFWorkbook();
12             //2.在workbook中添加一个sheet，对应Excel文件中的sheet
13             HSSFSheet hssfSheet = workbook.createSheet("列表1");
14             //3.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short
15             HSSFRow row = hssfSheet.createRow(0);
16             //4.创建单元格 设置表单  居中
17             HSSFCellStyle hssfCellStyle = workbook.createCellStyle();
18             HSSFCell hssfCell = null;
19             for (int i = 0; i < titles.length; i++) {
20                 hssfCell = row.createCell(i);//列索引从0开始
21                 hssfCell.setCellValue(titles[i]);//列名1
22                 hssfCell.setCellStyle(hssfCellStyle);//列居中显示
23             }
24             //5.填充数据
25             for (int i = 0; i < listMap.size(); i++) { //行数
26                 row = hssfSheet.createRow(i + 1); // 表数据的起始行数为 1
27                 //数据库数据
28                 Map<String, Object> map = listMap.get(i);
29                 for (int j = 0; j < titles.length; j++) { //列数
30                     row.createCell(j).setCellValue((String) map.get(keys[j]));
31                 }
32             }
33             // 6.将文件输出到客户端浏览器
34             try {
35                 workbook.write(out);
36                 out.flush();
37                 out.close();
38             } catch (Exception e) {
39                 e.printStackTrace();
40             }
41         } catch (Exception e) {
42             e.printStackTrace();
43         }
44     }
45 }

 1         //Excel表头、文件名（titles的长度和xml中sql查询的字段个数（keys长度）一致）
 2         String[] titles = {"编号", "姓名", "年龄"};
 3         //Excel文件名
 4         String name = "Excel表格下载";
 5         //数据库对应字段
 6         String[] keys = {"id", "name", "age"};
 7
 8         response.setContentType("application/binary;charset=UTF-8");
 9         try {
10             ServletOutputStream out = response.getOutputStream();
11             try {
12                 //设置文件头：一个参数是设置下载文件名
13                 response.setHeader("Content-Disposition", "attachment;fileName=" + URLEncoder.encode(name + ".xls", "UTF-8"));
14             } catch (UnsupportedEncodingException e1) {
15                 e1.printStackTrace();
16             }
17             // 数据库对应的需要导出的Excel数据
18             List<Map<String, Object>> listMap = exportExcelDAO.exportExcelData();
19             // MyExcelUtils下载Excel
20             MyExcelUtils.export(titles, out, listMap, keys);
21         } catch (Exception e) {
22             e.printStackTrace();
23         }