Excel File – Upload/Download using Apache POI + SpringBoot RestAPIs + Spring JPA + Thymeleaf to MySQL

In the post, Grokonez guides how to Upload/Download Excel Files to MySQL database using SpringBoot + Spring JPA with Apache POI library

Technologies

– Spring Boot – 2.0.6.RELEASE
– Spring JPA
– Thymeleaf
– MySQL
– Apache POI

Goal

We create a SpringBoot project as below:

-> Excel File:

-> Results:

-> MySQL:

Practice

Create SpringBoot project

We create a SpringBoot project with below dependencies:

	org.springframework.boot
	spring-boot-starter-thymeleaf


	org.springframework.boot
	spring-boot-starter-web



	org.apache.poi
	poi-ooxml
	3.17



	org.springframework.boot
	spring-boot-starter-data-jpa



    mysql
    mysql-connector-java

Customer Model

– Create Customer.java model:

package com.grokonez.excelfile.model;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "customer")
public class Customer {
	
	@Id
	@GeneratedValue(strategy = GenerationType.AUTO)
	private long id;
	
	@Column(name = "name")
	private String name;
	
	@Column(name = "address")
	private String address;
	
	@Column(name = "age")
	private int age;
 
	public Customer() {
	}
 
	public Customer(long id, String name, String address, int age) {
		this.id = id;
		this.name = name;
		this.address = address;
		this.age = age;
	}
 
	public long getId() {
		return id;
	}
 
	public void setId(long id) {
		this.id = id;
	}
 
	public String getName() {
		return name;
	}
 
	public void setName(String name) {
		this.name = name;
	}
 
	public String getAddress() {
		return address;
	}
 
	public void setAddress(String address) {
		this.address = address;
	}
 
	public int getAge() {
		return age;
	}
 
	public void setAge(int age) {
		this.age = age;
	}
 
	@Override
	public String toString() {
		return "Customer [id=" + id + ", name=" + name + ", address=" + address + ", age=" + age + "]";
	}
 
}

JPA Repository

– Create CustomerRepository.java:

package com.grokonez.excelfile.repository;

import org.springframework.data.repository.CrudRepository;

import com.grokonez.excelfile.model.Customer;

public interface CustomerRepository extends CrudRepository{
}

Excel Utils

– Implement Excel Utils:

package com.grokonez.excelfile.util;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.CreationHelper;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import com.grokonez.excelfile.model.Customer;

public class ExcelUtils {

	public static ByteArrayInputStream customersToExcel(List customers) throws IOException {
		String[] COLUMNs = {"Id", "Name", "Address", "Age"};
		try(
				Workbook workbook = new XSSFWorkbook();
				ByteArrayOutputStream out = new ByteArrayOutputStream();
		){
			CreationHelper createHelper = workbook.getCreationHelper();
	 
			Sheet sheet = workbook.createSheet("Customers");
	 
			Font headerFont = workbook.createFont();
			headerFont.setBold(true);
			headerFont.setColor(IndexedColors.BLUE.getIndex());
	 
			CellStyle headerCellStyle = workbook.createCellStyle();
			headerCellStyle.setFont(headerFont);
	 
			// Row for Header
			Row headerRow = sheet.createRow(0);
	 
			// Header
			for (int col = 0; col < COLUMNs.length; col++) {
				Cell cell = headerRow.createCell(col);
				cell.setCellValue(COLUMNs[col]);
				cell.setCellStyle(headerCellStyle);
			}
	 
			// CellStyle for Age
			CellStyle ageCellStyle = workbook.createCellStyle();
			ageCellStyle.setDataFormat(createHelper.createDataFormat().getFormat("#"));
	 
			int rowIdx = 1;
			for (Customer customer : customers) {
				Row row = sheet.createRow(rowIdx++);
	 
				row.createCell(0).setCellValue(customer.getId());
				row.createCell(1).setCellValue(customer.getName());
				row.createCell(2).setCellValue(customer.getAddress());
	 
				Cell ageCell = row.createCell(3);
				ageCell.setCellValue(customer.getAge());
				ageCell.setCellStyle(ageCellStyle);
			}
	 
			workbook.write(out);
			return new ByteArrayInputStream(out.toByteArray());
		}
	}
	
	public static List parseExcelFile(InputStream is) {
		try {
    		Workbook workbook = new XSSFWorkbook(is);
     
    		Sheet sheet = workbook.getSheet("Customers");
    		Iterator rows = sheet.iterator();
    		
    		List lstCustomers = new ArrayList();
    		
    		int rowNumber = 0;
    		while (rows.hasNext()) {
    			Row currentRow = rows.next();
    			
    			// skip header
    			if(rowNumber == 0) {
    				rowNumber++;
    				continue;
    			}
    			
    			Iterator cellsInRow = currentRow.iterator();

    			Customer cust = new Customer();
    			
    			int cellIndex = 0;
    			while (cellsInRow.hasNext()) {
    				Cell currentCell = cellsInRow.next();
    				
    				if(cellIndex==0) { // ID
    					cust.setId((long) currentCell.getNumericCellValue());
    				} else if(cellIndex==1) { // Name
    					cust.setName(currentCell.getStringCellValue());
    				} else if(cellIndex==2) { // Address
    					cust.setAddress(currentCell.getStringCellValue());
    				} else if(cellIndex==3) { // Age
    					cust.setAge((int) currentCell.getNumericCellValue());
    				}
    				
    				cellIndex++;
    			}
    			
    			lstCustomers.add(cust);
    		}
    		
    		// Close WorkBook
    		workbook.close();
    		
    		return lstCustomers;
        } catch (IOException e) {
        	throw new RuntimeException("FAIL! -> message = " + e.getMessage());
        }
	}
}

RestAPIs Controller

Upload Controller

– Implement UploadFileController.java:

package com.grokonez.excelfile.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;

import com.grokonez.excelfile.fileservice.FileServices;


@Controller
public class UploadFileController {
	
	@Autowired
	FileServices fileServices;
	
    @GetMapping("/")
    public String index() {
        return "multipartfile/uploadform.html";
    }
    
    @PostMapping("/")
    public String uploadMultipartFile(@RequestParam("uploadfile") MultipartFile file, Model model) {
		try {
			fileServices.store(file);
			model.addAttribute("message", "File uploaded successfully!");
		} catch (Exception e) {
			model.addAttribute("message", "Fail! -> uploaded filename: " + file.getOriginalFilename());
		}
        return "multipartfile/uploadform.html";
    }
}

Download Controller

– Implement DownloadFileController.java file:

package com.grokonez.excelfile.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.InputStreamResource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

import com.grokonez.excelfile.fileservice.FileServices;

@Controller
public class DownloadFileController {

	@Autowired
	FileServices fileServices;

    /*
     * Download Files
     */
	@GetMapping("/file")
	public ResponseEntity downloadFile() {
		
		HttpHeaders headers = new HttpHeaders();
        headers.add("Content-Disposition", "attachment; filename=customers.xlsx");
		
		return ResponseEntity
                .ok()
                .headers(headers)
                .body(new InputStreamResource(fileServices.loadFile()));	
	}
}

Viewers

– Implement upload/download viewers:

    
    
    
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Upload Excel File to MySQL
				

					

						Upload File:
						
					
					Upload
				
				

					
					Download Excel File from MySQL
				
			
		
	
	
%MINIFYHTML914833f012e7a123f03df5d6debe624919%

Application Config

– In application.properties, add configuration:

spring.datasource.url=jdbc:mysql://localhost:3306/testdb
spring.datasource.username=root
spring.datasource.password=12345
spring.jpa.generate-ddl=true

SourceCode

– Excel File: customers.xlsx
– SourceCode: SpringBootUploadDownloadExcelFile