The data in Excel format:
JSP page:
<body>
<h2>上传用户信息</h2>
<form method="post" action="<%= request.getContextPath() %>/user/excel/upload"
enctype="multipart/form-data">
<input type="file" name="file1">
<input type="file" name="file2">
<input type="text" name="username">
<input type="submit" name="" value="上传">
</form>
<a href="<%= request.getContextPath() %>/user/excel/output">下载</a>
</body>
maven project specific process:
1, the required jar package:
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>4.1.1</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>4.1.1</version>
</dependency>
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.4</version>
</dependency>
2, upload the configuration file parser in the spring.xml: Spring to help deal with uploaded files, but also the spring after the treatment process the object again encapsulated as objects MultipartFile
<!--上传的文件解析器-->
<bean id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="defaultEncoding" value="UTF-8"></property>
<property name="maxInMemorySize" value="10485760"></property>
</bean>
3, upload an Excel file:
First, upload form data from the form encapsulated as objects: a text, two file file
Packaging classes:
public class FormItems {
private String username;
private MultipartFile file1;
private MultipartFile file2;
。。。
setter、getter略
}
Controller level code:
using the Spring, the form data package automatically as a custom object (name of the form data and custom objects correspond to attribute names)
//上传Excel文件
@RequestMapping("/excel/upload")
@ResponseBody
public Result doImportExcel(FormItems items) {
InputStream inputStream=null;
InputStream inputStream2=null;
//仅仅输出一下上传的用户名，没有其他操作；
System.out.println("用户名："+items.getUsername());
try {
//得到把文件转为输出流
inputStream = items.getFile1().getInputStream();
inputStream2 = items.getFile2().getInputStream();
//把Excel里的用户数据封装进list
List<User> list = OperateUploadFile.saveUploadFile(inputStream);
List<User> list2 = OperateUploadFile.saveUploadFile(inputStream2);
//把list里面的user全部放到数据库
int save = userService.save(list);
int save2 = userService.save(list2);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally {
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (inputStream2 != null) {
try {
inputStream2.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Code top: the user data in Excel encapsulated into a list of process encapsulation methods:
public static List<User> saveUploadFile(InputStream inputStream) throws IOException {
Workbook workbook = WorkbookFactory.create(inputStream);
Sheet sheet = workbook.getSheetAt(0);
//拿到sheet中最后一行数据所在行：用于循环输出下标
int lastRowNum = sheet.getLastRowNum();
System.out.println("lastRowNum = " + lastRowNum);
//把Excel的数据全部封装到list集合里面
List<User> list=new ArrayList<>();
for (int i = 1; i <=lastRowNum ; i++) {
Row row = sheet.getRow(i);
User user = new User();
user.setUsername(row.getCell(1).getStringCellValue());
user.setPassword(row.getCell(2).getStringCellValue());
list.add(user);
}
return list;
}
4, downloading the Excel file:
the user to get all the data in the database, can be encapsulated into a Workbook object; workbook and then the object is output.
Controller level code:
@RequestMapping("/excel/output")
@ResponseBody
public void exportExcel(HttpServletResponse response) {
//得到数据库所有的User数据
List<User> allUser = userService.findAllUser();
//添加Excel的标题行
String[] title = {"ID", "USERNAME", "PASSWORD"};
// create a new workbook
Workbook wb = new HSSFWorkbook();
// create a new sheetL
Sheet s = wb.createSheet();
// declare a row object reference
Row r = s.createRow(0);
// declare a cell object reference
for (int i = 0; i < title.length; i++) {
r.createCell(i).setCellValue(title[i]);
}
//添加Excel数据行
for (int i = 0; i < allUser.size(); i++) {
User user = allUser.get(i);
Row row = s.createRow(i+1);
row.createCell(0).setCellValue(user.getId());
row.createCell(1).setCellValue(user.getUsername());
row.createCell(2).setCellValue(user.getPassword());
}
// 生成文件名
String filename = UUID.randomUUID().toString() + ".xls";
System.out.println("filename = " + filename);
// 处理下载
response.setCharacterEncoding("UTF-8");
response.setContentType("application/vnd.ms-excel");
response.setHeader("Content-Disposition", "attachment; filename=" + filename);
//得到输出对象
// response.getWriter();
try {
wb.write(response.getOutputStream());
} catch (IOException e) {
e.printStackTrace();
}
}
End of the text and then attach the apache poi official document:
http://poi.apache.org/components/spreadsheet/
