Springboot uploads excel and imports or updates table data into mySql database

This article mainly describes the process of uploading excel under the Springboot-mybatis framework and importing it into the mysql database. If the user id already exists, update and modify the information in the database. Since the front-end and back-end separation technology is used, the record here It is mainly the back-end java part. The functions are realized by docking with the front-end interface, using front-end frameworks such as layui to interface with it, or you can write the front-end code yourself. This article starts with the Controller and starts with the import process, including the conversion of the dictionary table.

1. Import annotations in the pom.xml file, mainly using POI

<dependency>
      <groupId>org.apache.poi</groupId>
      <artifactId>poi-ooxml</artifactId>
      <version>3.9</version>
</dependency>
<dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>1.3.1</version>
</dependency>
<dependency>
      <groupId>commons-io</groupId>
      <artifactId>commons-io</artifactId>
      <version>2.4</version>
</dependency>

2. Controller interface

	@PostMapping("/save")
	public String addUser(@RequestParam("file") MultipartFile file) {
		String fileName = file.getOriginalFilename();
		try {
			return sysService.batchImport(fileName, file);
		} catch (MyException e) {
			e.printStackTrace ();
			return e.getMessage();
		}catch(Exception e){
			e.printStackTrace ();
			return "File exception, import failed";
			
		}
	}

3. Service layer interface

	boolean import(String fileName, MultipartFile file) throws Exception;

4. Business layer implementation class

        @Transactional(readOnly = false,rollbackFor = Exception.class)
	@Override
	public boolean import(String fileName, MultipartFile file) throws Exception {
		Map<String, Integer> departmentMap = findDepartment();
		Map<String, Integer> roleMap = findRole();
		boolean notNull = false;
	        List<User> userList = new ArrayList<User>();
		if (!fileName.matches("^.+\\.(?i)(xls)$") && !fileName.matches("^.+\\.(?i)(xlsx)$")) {
			 throw new MyException("The format of the uploaded file is incorrect");
		}
		boolean isExcel2003 = true;
		if (fileName.matches("^.+\\.(?i)(xlsx)$")) {
			isExcel2003 = false;
		}
		InputStream  is = file.getInputStream();
			Workbook wb = null;
			if (isExcel2003) {
				wb = new HSSFWorkbook(is);
			} else {
				wb = new XSSFWorkbook(is);
			}
			Sheet sheet = wb.getSheetAt(0);
			if(sheet!=null){
				notNull = true;
			}
		User user;
		for (int r = 1; r <= sheet.getLastRowNum(); r++) {
			Row row = sheet.getRow(r);
			if (row == null){
				continue;
			}
			user = new User();
	
			if( row.getCell(0).getCellType() !=1){
				throw new MyException("Import failed (line "+(r+1)+", please set the ID cell format to text format)");
			}
			String id = row.getCell(0).getStringCellValue();
			if(id==null || id.isEmpty()){
				 throw new MyException("Import failed (line "+(r+1)+", ID not filled in)");
			}
			String name = row.getCell(1).getStringCellValue();
			if(name==null || name.isEmpty()){
				 throw new MyException("Import failed (line "+(r+1)+", name is not filled in)");
			}
			String department = row.getCell(2).getStringCellValue();
			if(departmentMap.get(department)==null){
				 throw new MyException("Import failed (line "+(r+1)+", this unit does not exist or the unit is not filled in)");
			}
			String role = row.getCell(3).getStringCellValue();
			if(roleMap.get(role)==null){
				throw new MyException("Import failed (line "+(r+1)+", this role does not exist or the role is not filled in)");
			}

			datedate;
			if(row.getCell(4).getCellType() !=0){
				throw new MyException("Import failed (line "+(r+1)+", entry date format is incorrect or not filled in)");
				}else{
					 date = row.getCell(4).getDateCellValue();
				}

				user.setId(id);
				user.setName(name);
				user.setDepartmentId((int) departmentMap.get(department));
				user.setRoleId((int) roleMap.get(role));
				user.setDate(date);
				userList.add(user);
			}
		for (User user : userList) {
			String id = user.getId();
			int cnt = userMapper.selectById(id);
			if (cnt == 0) {
				userMapper.addUser(user);
			} else {
				userMapper.updateUserById(user);
			}
		}
		return notNull;
	}