Spring Boot Upload File Example (2024)

In this tutorial, we'll show you how to upload file in Spring Boot application with following rest endpoints.

1. POST method to Upload file using MultipartFile[] file as a parameter.
2. GET method to list all files from the file storage folder.

Create Spring Boot Project from Spring Initializer site https://start.spring.io/

Project Structure

Maven Dependency

All we need is spring-boot-starter-web dependency in pom.xml, add org.projectlombok for auto generating getters/setters/constructor.

<?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>2.2.4.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.techgeeknext</groupId>
	<artifactId>spring-boot-upload-file-example</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>spring-boot-upload-file-example</name>
	<description>Spring Boot upload file</description>

	<properties>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<optional>true</optional>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

Constant File

Create File Utility class, for keeping constant variables:

package com.techgeeknext.util;

import java.nio.file.Path;
import java.nio.file.Paths;

public final class FileUtil {

  private FileUtil() {
    // restrict instantiation
  }

  public static final String folderPath =  "incoming-files//";
  public static final Path filePath = Paths.get(folderPath);

}

RestController to upload file

Create RestController class and define below rest endpoint:

1. POST method to Upload file using MultipartFile[] file as a parameter.
2. GET method to list all files from the file storage folder.

package com.techgeeknext.controller;

import com.techgeeknext.util.FileUtil;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.CrossOrigin;
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 java.io.File;
import java.nio.file.Files;
import java.nio.file.Paths;

@Controller
//@CrossOrigin(origins = "http://localhost:8082") open for specific port
@CrossOrigin() // open for all ports
public class FileUploadController {


    /**
     * Method to upload file
     *
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public ResponseEntity<String> uploadFile(@RequestParam("file") MultipartFile file) {
        try {
            createDirIfNotExist();

            byte[] bytes = new byte[0];
            bytes = file.getBytes();
            Files.write(Paths.get(FileUtil.folderPath + file.getOriginalFilename()), bytes);
            return ResponseEntity.status(HttpStatus.OK)
                    .body("Files uploaded successfully: " + file.getOriginalFilename());
        } catch (Exception e) {
            return ResponseEntity.status(HttpStatus.EXPECTATION_FAILED)
                    .body("Exception occurred for: " + file.getOriginalFilename() + "!");
        }
    }

    /**
     * Create directory to save files, if not exist
     */
    private void createDirIfNotExist() {
        //create directory to save the files
        File directory = new File(FileUtil.folderPath);
        if (!directory.exists()) {
            directory.mkdir();
        }
    }

    /**
     * Method to get the list of files from the file storage folder.
     *
     * @return file
     */
    @GetMapping("/files")
    public ResponseEntity<String[]> getListFiles() {
        return ResponseEntity.status(HttpStatus.OK)
                .body(new java.io.File(FileUtil.folderPath).list());
    }

}

Spring Boot Main Application

Start the Spring main application:

package com.techgeeknext;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringBootUploadFileApplication {

  public static void main(String[] args) {
    SpringApplication.run(SpringBootUploadFileApplication.class, args);
  }

}

Test Upload File Example

1. POST - Upload file

   Open POSTMAN and select the value to upload the file by using http://localhost:8282/upload?file request.

2. GET - List of uploaded files

   Open POSTMAN and get the list of uploaded file names by using http://localhost:8282/files request.

Download Source Code

The full source code for this article can be found on below.
Download it here - Spring Boot Upload File Example