首先添加依赖。
然后写数据库对应的实体类
然后mapper层，有一个查询方法，有一个添加方法。
然后是mapper映射文件，业务层。这里就不列举了。
重点说一下controller。
@Controller
public class SaleController {
@Autowired
private SaleServiceImpltt;
//这一个方法是查询出数据显示到freemark页面
@RequestMapping("/index")
public String select(Model model, Integer id, Integer price, Integer quantity, Integer totalPrice,Integer userId, Integer productId){
List list=tt.select(id,price,quantity,totalPrice,userId,productId);
model.addAttribute("list",list);
return "index";
}
//这是个是导入文件
@RequestMapping("/excel/upload")
public String fileUpload(@RequestParam("file") MultipartFile file,Integer price,Integer quantity,Integer totalPrice,Integer userId,Integer productId)throws IOException {
long size=file.getSize();
HSSFWorkbook workbook =new HSSFWorkbook(new POIFSFileSystem(file.getInputStream()));
//获得有多少sheet
int numberOfSheets = workbook.getNumberOfSheets();
//默认只有一个sheet
HSSFSheet sheet = workbook.getSheetAt(0);
//获得sheet有多少行
int rows = sheet.getPhysicalNumberOfRows();
//遍历行
for (int j =0; j < rows; j++) {
if (j ==0) {
continue;//标题行(省略)
}
for (int k =0; k <1; k++) {
//这个循环是这个表格有多少行，就循环多少次，每次循环都会获得除了id那一列的每一列数据（id为递增，不需要添加），因为我的数据全都是int类型，但是获取的是double类型，所以我把它转化为了int类型。row.getcell()是获取列, two.getNumericCellValue()是获取这个列的这个数据,然后调用insert（）方法，最后插入进数据库。
HSSFRow row = sheet.getRow(j);
HSSFCell two = row.getCell(1);
HSSFCell three = row.getCell(2);
HSSFCell four = row.getCell(3);
HSSFCell five = row.getCell(4);
HSSFCell six = row.getCell(5);
double twoa = two.getNumericCellValue();
int twob = (int) twoa;
double threea = three.getNumericCellValue();
int threeb = (int) threea;
double foura = four.getNumericCellValue();
int fourb = (int) foura;
double fivea = five.getNumericCellValue();
int fiveb = (int) fivea;
double sixa = six.getNumericCellValue();
int sixb = (int) sixa;
tt.insert(twob, threeb, fourb, fiveb, sixb);
}
}
return "poi";
}
//生成user表excel
@GetMapping(value ="/excel/getUser")
@ResponseBody
public String getUser(HttpServletResponse response,Integer id,Integer price,Integer quantity,Integer totalPrice,Integer userId,Integer productId)throws Exception{
HSSFWorkbook workbook =new HSSFWorkbook();
HSSFSheet sheet = workbook.createSheet("统计表");
createTitle(workbook,sheet);
//userService.getAll();
//而导出方法首先要查询出来数据库里面的数据，存到rows中，然后设置生成excel表的格式，把数据库查询出来的数据插入进去。
List rows=tt.select(id,price,quantity,totalPrice,userId,productId);
System.out.print("aaaaaaaaaaaa"+rows);
HSSFCellStyle style = workbook.createCellStyle();
style.setDataFormat(HSSFDataFormat.getBuiltinFormat("m/d/yy h:mm"));
//新增数据行，并且设置单元格数据
int rowNum=1;
for(Sale user:rows){
HSSFRow row = sheet.createRow(rowNum);
row.createCell(0).setCellValue(user.getId());
row.createCell(1).setCellValue(user.getPrice());
row.createCell(2).setCellValue(user.getProductId());
row.createCell(3).setCellValue(user.getQuantity());
row.createCell(4).setCellValue(user.getUserId());
rowNum++;
}
String fileName ="导出excel例子.xls";
//生成excel文件
buildExcelFile(fileName, workbook);
//浏览器下载excel
buildExcelDocument(fileName,workbook,response);
return "Poi";
}
//创建表头
private void createTitle(HSSFWorkbook workbook,HSSFSheet sheet){
HSSFRow row = sheet.createRow(0);
//设置列宽，setColumnWidth的第二个参数要乘以256，这个参数的单位是1/256个字符宽度
sheet.setColumnWidth(1,12*256);
sheet.setColumnWidth(3,17*256);
//设置为居中加粗
HSSFCellStyle style = workbook.createCellStyle();
HSSFFont font = workbook.createFont();
font.setBold(true);
//style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
style.setFont(font);
HSSFCell cell;
cell = row.createCell(0);
cell.setCellValue("id");
cell.setCellStyle(style);
cell = row.createCell(1);
cell.setCellValue("price");
cell.setCellStyle(style);
cell = row.createCell(2);
cell.setCellValue("quantity");
cell.setCellStyle(style);
cell = row.createCell(3);
cell.setCellValue("totalprice");
cell = row.createCell(4);
cell.setCellValue("userId");
cell = row.createCell(5);
cell.setCellValue("productId");
cell.setCellStyle(style);
}
//生成excel文件
protected void buildExcelFile(String filename,HSSFWorkbook workbook)throws Exception{
FileOutputStream fos =new FileOutputStream(filename);
workbook.write(fos);
fos.flush();
fos.close();
}
//浏览器下载excel
protected void buildExcelDocument(String filename,HSSFWorkbook workbook,HttpServletResponse response)throws Exception{
response.setContentType("application/vnd.ms-excel");
response.setHeader("Content-Disposition","attachment;filename="+ URLEncoder.encode(filename,"utf-8"));
OutputStream outputStream = response.getOutputStream();
workbook.write(outputStream);
outputStream.flush();
outputStream.close();
}
然后最后写ftl页面
| 用户名 | 价格 | 数量 | 总价 | 销售者id | 销售产品id |
|---|---|---|---|---|---|
| ${item.id} | ${item.price} | ${item.quantity} | ${item.totalPrice} | ${item.userId} | ${item.productId} |
这是用户信息页
//这个from表单就是选择excel文件，上传到excel/upload方法里面。