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Effortless Spring Boot File Upload and Download with database: A Comprehensive Guide

Welcome to the world of “Spring Boot File Upload and Download with database.” In today’s data-driven era, handling files within your Spring Boot applications, while seamlessly integrating them with a database, is essential. This article will guide you through the process of efficiently managing file uploads and downloads in your Spring Boot projects, with a strong emphasis on database integration. By the end, you’ll have the knowledge and skills to create a robust and responsive file management system that ensures data integrity and a superb user experience.

In today’s data-driven world, handling file uploads and downloads within your Spring Boot applications is a crucial aspect of building feature-rich and user-friendly platforms. In this comprehensive guide: Effortless Spring Boot File Upload and Download with database, we will embark on a journey to demystify and streamline the process of effortlessly managing file uploads and downloads within Spring Boot applications, with a special focus on database integration. By the end of this guide, you’ll possess the knowledge and skills needed to handle files in your Spring Boot projects efficiently.

Spring Boot offers an array of tools and features that simplify the process of handling files, and when combined with database integration, it opens up a world of possibilities. From storing and retrieving files to managing metadata and access control, this guide will equip you with the expertise needed to implement a robust and scalable file management system within your Spring Boot application. Whether you’re dealing with images, documents, or any other file type, understanding the intricacies of “Spring Boot File Upload and Download with database” is vital for delivering a seamless and responsive user experience.

Throughout this article, we will explore various techniques and best practices for integrating file handling with a database using Spring Boot. We will delve into the mechanics of uploading files, storing them efficiently, and enabling users to download their files securely. Additionally, we’ll discuss how to manage file metadata, handle concurrency issues, and ensure data integrity within your database. So, if you’re ready to enhance your Spring Boot skills and build feature-rich applications with effortless file upload and download capabilities, you’re in the right place. Let’s dive into the world of “Spring Boot File Upload and Download with database” and unlock its full potential.




In this article we will cover the second way where we will store the direct image into the file system and store the file system path into the database. In the previous article, we already discussed the first approach.

Just to keep this article simple, we will use H2 in-memory database instead of Real database but you can connect to any database for production. You just need to add the database dependency that you are using and data source properties that’s it.

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Spring Boot File Upload and Download with database: Complete Example


We will create this example step by step, follow this tutorial till the end

Create spring boot project


There are many different ways to create a spring boot application, you can follow the below articles to create one –

>> Create spring boot application using Spring initializer
>> Create spring boot application in Spring tool suite [STS]
>> Create spring boot application in IntelliJ IDEA

Add maven dependencies


Open pom.xml and add the following dependencies –

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.7.3</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>in.bushansirgur</groupId>
	<artifactId>image-upload-download</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>image-upload-download</name>
	<description>Spring boot image upload and download project</description>
	<properties>
		<java.version>1.8</java.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-jpa</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
			<scope>runtime</scope>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>com.h2database</groupId>
			<artifactId>h2</artifactId>
			<scope>runtime</scope>
		</dependency>
		
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
				<configuration>
					<excludes>
						<exclude>
							<groupId>org.projectlombok</groupId>
							<artifactId>lombok</artifactId>
						</exclude>
					</excludes>
				</configuration>
			</plugin>
		</plugins>
	</build>

</project>
  • We have added the spring-boot-starter-web dependency to create web application and REST APIs




  • We have added the spring-boot-starter-data-jpa dependency to perform the database operations.
  • We added an h2 dependency for storing the data in the database, it is a in-memory database.
  • Also we have added the spring-boot-devtools dependency which is for development purpose

Configure Data source


As we discussed above, we will use H2 in-memory database instead of Real database such as MySQL, PostgreSQL or Oracle. Open application.properties file and the following content

spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=password
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect
spring.h2.console.enabled=true
spring.jpa.hibernate.ddl-auto=update

Create a JPA Entity


We will create a JPA entity to map the database table with Java object. Create ProductImage.java inside src/main/java and add the following content

package in.bushansirgur.springbootimageupload.entity;

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

@Entity
@Table(name = "tbl_product_image")
public class ProductImage {
	
	@Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;
    private String type;
    private String imagePath;
	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 getType() {
		return type;
	}
	public void setType(String type) {
		this.type = type;
	}
	public String getImagePath() {
		return imagePath;
	}
	public void setImagePath(String imagePath) {
		this.imagePath = imagePath;
	}
	
    
}
  • We have added @Entity annotation to mark this class as JPA entity
  • We have added @Table annotation to provide the database table information. @Table annotation indicates that this class is mapped with database table tbl_product_image
  • We have also added couple more annotataions @Id and @GeneratedValue annotation.
  • We also added the @Lob annotation for the field imageData which indicate that a persistent property or field should be persisted as a large object to a database-supported large object type.

Create JPA Repository for ProductImage


We will create a Interface and extend it with JpaRepository so the we can use the JpaRepository predefined methods to perform the database operations. Create a interface ProjectImageRepository.java inside src/main/java and add the following content

package in.bushansirgur.springbootimageupload.repository;

import java.util.Optional;

import org.springframework.data.jpa.repository.JpaRepository;

import in.bushansirgur.springbootimageupload.entity.ProductImage;

public interface ProductImageRepository extends JpaRepository<ProductImage, Long> {
	
	Optional<ProductImage> findByName(String fileName);
}

We have created a JPA finder method findByName to get the Product image from the database by its image name.



Create a Service class for Product Image


We will create Service class for Product image where will call the JpaRepository methods to save and retrieve the image. While calling the repository methods we will store the file into the file system and store the file path into the database. Similarly while retrieving the image from the database we will read that file into byte[] and return it. Create a class ProductImageService.java under src/main/java and add the following content

package in.bushansirgur.springbootimageupload.service;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.util.Optional;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import in.bushansirgur.springbootimageupload.entity.ProductImage;
import in.bushansirgur.springbootimageupload.repository.ProductImageRepository;

@Service
public class ProductImageService {
	
	@Autowired
    private ProductImageRepository imageRepo;
	
	private final String PATH = "C:\\workspace\\";
	
	public ProductImage uploadImage(MultipartFile file) throws IOException {
		String fullPath = PATH+file.getOriginalFilename();
		ProductImage pImage = new ProductImage();
		pImage.setName(file.getOriginalFilename());
		pImage.setType(file.getContentType());
		pImage.setImagePath(fullPath);
		
		file.transferTo(new File(fullPath));
		return imageRepo.save(pImage);
	}
	
	public byte[] downloadImage(String fileName) throws IOException{
        Optional<ProductImage> imageObject = imageRepo.findByName(fileName);
        String fullPath = imageObject.get().getImagePath();
        return Files.readAllBytes(new File(fullPath).toPath());
    }
}

Create Controller to expose REST end points for Upload and Download Image


We will create a Controller for ProductImage where we will expose 2 REST end points /upload for uploading the image and /download/{fileName} for downloading the image. Create ProductImageController.java under src/main/java and add the following content

package in.bushansirgur.springbootimageupload.controller;

import java.io.IOException;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import in.bushansirgur.springbootimageupload.service.ProductImageService;

@RestController
public class ProductImageController {
	
	@Autowired
	private ProductImageService productImageService;
	
	@ResponseStatus(value = HttpStatus.OK)
	@PostMapping("/upload")
	public void uploadImage(@RequestParam("productImage")MultipartFile file) throws IOException{
		productImageService.uploadImage(file);
	}
	
	@GetMapping("/download/{fileName}")
	public ResponseEntity<byte[]> downloadImage(@PathVariable String fileName) throws IOException {
		byte[] image = productImageService.downloadImage(fileName);
		return ResponseEntity.status(HttpStatus.OK).contentType(MediaType.valueOf("image/png")).body(image);
	}
}

Run the app


Run the application using the below maven command –

mvn spring-boot:run

Once the tomcat server is up, open Postman make a HTTP POST request to upload image to the URL http://localhost:8080/upload. In order to send image, inside the HTTP body select form-data, enter productImage as Key and select image which you want to upload as Value.

Spring Boot File Upload and Download with database

When you send the request, you will see the HTTP status code 200 and you can verify in the database that a new entry has been inserted to the database.

114

Next send the another HTTP GET request to download the image to the URL http://localhost:8080/download/101.png. You will see the image in the response body downloaded from the database.

112

Conclusion

In conclusion, mastering “Spring Boot File Upload and Download with database” is a significant step toward building modern, user-centric applications. Throughout this comprehensive guide, we’ve explored the intricacies of seamlessly integrating file management with database systems in Spring Boot. You’ve learned best practices for uploading, storing, retrieving, and securely delivering files, all while ensuring data integrity and a stellar user experience.

With this newfound knowledge, you’re well-equipped to tackle the challenges of handling files within your Spring Boot projects. Whether you’re building content-rich websites, e-commerce platforms, or any application that involves file management, you now have the tools and insights to create efficient and scalable solutions.

As you continue to develop your Spring Boot applications, remember that effective file management is not only a technical accomplishment but also a way to enhance user satisfaction and streamline data workflows. So, go ahead and implement the techniques and strategies you’ve learned here to elevate your Spring Boot projects and delight your users with seamless file uploads and downloads, all backed by a robust database.

Additional Resources

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Bushan Sirgur

Hey guys, I am Bushan Sirgur from Banglore, India. Currently, I am working as an Associate project in an IT company.

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