protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    Part filePart = request.getPart("file");
    InputStream fileContent = filePart.getInputStream();

    File file = new File("D:/temp");
    OutputStream outputStream = new FileOutputStream(file);
    org.apache.tomcat.util.http.fileupload.IOUtils.copy(fileContent, outputStream);
    outputStream.close();
    ProcessFile.readFile(file); //to read the file
}

public class ProcessFile {

public static void readFile(File file) throws IOException{

    FileInputStream input = new FileInputStream(file);

    Workbook workbook = new XSSFWorkbook(input);
    Sheet firstSheet = workbook.getSheetAt(0);
    Iterator<Row> iterator = firstSheet.iterator();

    while (iterator.hasNext()) {
        Row nextRow = iterator.next();
        Iterator<Cell> cellIterator = nextRow.cellIterator();
        int colNum = 1;

        Employee emp = new Employee();

        while (cellIterator.hasNext()) {
            Cell cell = cellIterator.next();
            String temp = "";

            cell.setCellType(Cell.CELL_TYPE_STRING);
            temp = cell.getStringCellValue();

            //set employee object

            switch(colNum){
                case 1:
                    emp.setNumber(Integer.parseInt(temp));
                    break;
                case 2:
                    emp.setName(temp);
                    break;
                case 3:
                    emp.setCity(temp);
                    break;
                case 4:
                    emp.setSalary(Integer.parseInt(temp));
                    break;
            }

            colNum++;
        }
        System.out.println(emp.getNumber()+" "+emp.getName()+" "+emp.getCity()+" "+emp.getSalary());

    }

    workbook.close();
    input.close();
}

java.lang.ClassNotFoundException: org.apache.poi.ss.usermodel.Workbook
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1720)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
at BrowseFile.doPost(BrowseFile.java:63)