How to read excel file using spring boot

Finally found the solution.

Html file for uploading the form is

<form th:action="@{/import}" method="post" enctype="multipart/form-data">
    <input type="file" th:name="file" />
    <input th:type="submit" value="Import" />
</form>

Controller class is

@PostMapping("/import")
public void mapReapExcelDatatoDB(@RequestParam("file") MultipartFile reapExcelDataFile) throws IOException {
    
    List<Test> tempStudentList = new ArrayList<Test>();
    XSSFWorkbook workbook = new XSSFWorkbook(reapExcelDataFile.getInputStream());
    XSSFSheet worksheet = workbook.getSheetAt(0);
    
    for(int i=1;i<worksheet.getPhysicalNumberOfRows() ;i++) {
        Test tempStudent = new Test();
            
        XSSFRow row = worksheet.getRow(i);
            
        tempStudent.setId((int) row.getCell(0).getNumericCellValue());
        tempStudent.setContent(row.getCell(1).getStringCellValue());
        tempStudentList.add(tempStudent);   
    }
}

Make sure to add the dependecy

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.12</version>
</dependency>
<!-- excel 2007 over-->
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.12</version>
</dependency>

Now it will work fine.

Use Apache POI library which is easily available using Maven Dependencies.

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.15</version>
  </dependency>

Code to read file

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Iterator;

public class ApachePOIExcelRead {

    private static final String FILE_NAME = "/tmp/MyFirstExcel.xlsx";

    public static void main(String[] args) {

        try {

            FileInputStream excelFile = new FileInputStream(new File(FILE_NAME));
            Workbook workbook = new XSSFWorkbook(excelFile);
            Sheet datatypeSheet = workbook.getSheetAt(0);
            Iterator<Row> iterator = datatypeSheet.iterator();

            while (iterator.hasNext()) {

                Row currentRow = iterator.next();
                Iterator<Cell> cellIterator = currentRow.iterator();

                while (cellIterator.hasNext()) {

                    Cell currentCell = cellIterator.next();
                    //getCellTypeEnum shown as deprecated for version 3.15
                    //getCellTypeEnum ill be renamed to getCellType starting from version 4.0
                    if (currentCell.getCellTypeEnum() == CellType.STRING) {
                        System.out.print(currentCell.getStringCellValue() + "--");
                    } else if (currentCell.getCellTypeEnum() == CellType.NUMERIC) {
                        System.out.print(currentCell.getNumericCellValue() + "--");
                    }

                }
                System.out.println();

            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}

Please modify above program as per your requirement. If you know your excel file column index then you can direct row to read cell e.g.row.getCell(0) where row object like XSSFRow row = (XSSFRow) iterator.next();

Hope this will helps you

Reference