Spring Boot Multipart File upload example

In this tutorial, I will show you how to upload and download files with a Spring Boot Rest APIs to/from a static folder. We also use Spring Web MultipartFile interface to handle HTTP multi-part requests.

This Spring Boot App works with:
Angular Client
Vue Client / Vuetify Client
React Client / React Hooks Client

Related Posts:
How to upload multiple files in Java Spring Boot
Spring Boot: Upload/Import Excel file data into MySQL Database
Spring Boot: Upload/Import CSV file data into MySQL Database

Deployment: Deploy Spring Boot App on AWS – Elastic Beanstalk


Spring Boot Rest APIs for uploading Files

Our Spring Boot Application will provide APIs for:

  • uploading File to a static folder in the Server
  • downloading File from server with the link
  • getting list of Files’ information (file name & url)

These are APIs to be exported:

MethodsUrlsActions
POST/uploadupload a File
GET/filesget List of Files (name & url)
GET/files/[filename]download a File

This is the static folder that stores all uploaded files:

spring-boot-multipart-file-upload-example-static-folder

If you want to store files in database like this:
spring-boot-upload-files-to-database-table-files

You can find instruction at:
Spring Boot Upload/Download File to/from Database example

Technology

  • Java 8
  • Spring Boot 2 (with Spring Web MVC)
  • Maven 3.6.1

Project Structure

spring-boot-multipart-file-upload-example-project-structure

Let me explain it briefly.

FileInfo contains information of the uploaded file.
FilesStorageService helps us to initialize storage, save new file, load file, get list of Files’ info, delete all files.
FilesController uses FilesStorageService to export Rest APIs: POST a file, GET all files’ information, download a File.
FileUploadExceptionAdvice handles exception when the controller processes file upload.
application.properties contains configuration for Servlet Multipart.
uploads is the static folder for storing files.
pom.xml for Spring Boot dependency.

Setup Spring Boot project

Use Spring web tool or your development tool (Spring Tool Suite, Eclipse, Intellij) to create a Spring Boot project.

Then open pom.xml and add these dependencies:

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

Create Service for File Storage

First we need an interface that will be autowired in the Controller.
In service folder, create FilesStorageService interface like following code:

service/FilesStorageService.java

package com.bezkoder.spring.files.upload.service;

import java.nio.file.Path;
import java.util.stream.Stream;

import org.springframework.core.io.Resource;
import org.springframework.web.multipart.MultipartFile;

public interface FilesStorageService {
  public void init();

  public void save(MultipartFile file);

  public Resource load(String filename);

  public void deleteAll();

  public Stream<Path> loadAll();
}

Now we create implementation of the interface.

service/FilesStorageServiceImpl.java

package com.bezkoder.spring.files.upload.service;

import java.io.IOException;
import java.net.MalformedURLException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.stream.Stream;

import org.springframework.core.io.Resource;
import org.springframework.core.io.UrlResource;
import org.springframework.stereotype.Service;
import org.springframework.util.FileSystemUtils;
import org.springframework.web.multipart.MultipartFile;

@Service
public class FilesStorageServiceImpl implements FilesStorageService {

  private final Path root = Paths.get("uploads");

  @Override
  public void init() {
    try {
      Files.createDirectory(root);
    } catch (IOException e) {
      throw new RuntimeException("Could not initialize folder for upload!");
    }
  }

  @Override
  public void save(MultipartFile file) {
    try {
      Files.copy(file.getInputStream(), this.root.resolve(file.getOriginalFilename()));
    } catch (Exception e) {
      throw new RuntimeException("Could not store the file. Error: " + e.getMessage());
    }
  }

  @Override
  public Resource load(String filename) {
    try {
      Path file = root.resolve(filename);
      Resource resource = new UrlResource(file.toUri());

      if (resource.exists() || resource.isReadable()) {
        return resource;
      } else {
        throw new RuntimeException("Could not read the file!");
      }
    } catch (MalformedURLException e) {
      throw new RuntimeException("Error: " + e.getMessage());
    }
  }

  @Override
  public void deleteAll() {
    FileSystemUtils.deleteRecursively(root.toFile());
  }

  @Override
  public Stream<Path> loadAll() {
    try {
      return Files.walk(this.root, 1).filter(path -> !path.equals(this.root)).map(this.root::relativize);
    } catch (IOException e) {
      throw new RuntimeException("Could not load the files!");
    }
  }
}

Define Data Models

Let’s create FileInfo model which has fields: name & url.

model/FileInfo.java

package com.bezkoder.spring.files.upload.model;

public class FileInfo {
  private String name;
  private String url;

  public FileInfo(String name, String url) {
    this.name = name;
    this.url = url;
  }

  public String getName() {
    return this.name;
  }

  public void setName(String name) {
    this.name = name;
  }

  public String getUrl() {
    return this.url;
  }

  public void setUrl(String url) {
    this.url = url;
  }
}

Define Response Message

The ResponseMessage is for message to client that we’re gonna use in Rest Controller and Exception Handler.

message/ResponseMessage.java

package com.bezkoder.spring.files.upload.message;

public class ResponseMessage {
  private String message;

  public ResponseMessage(String message) {
    this.message = message;
  }

  public String getMessage() {
    return message;
  }

  public void setMessage(String message) {
    this.message = message;
  }

}

Create Controller for upload & download Files

In controller package, we create FilesController.

controller/FilesController.java

package com.bezkoder.spring.files.upload.controller;

import java.util.List;
import java.util.stream.Collectors;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
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.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.mvc.method.annotation.MvcUriComponentsBuilder;

import com.bezkoder.spring.files.upload.model.FileInfo;
import com.bezkoder.spring.files.upload.model.ResponseMessage;
import com.bezkoder.spring.files.upload.service.FilesStorageService;

@Controller
@CrossOrigin("http://localhost:8081")
public class FilesController {

  @Autowired
  FilesStorageService storageService;

  @PostMapping("/upload")
  public ResponseEntity<ResponseMessage> uploadFile(@RequestParam("file") MultipartFile file) {
    String message = "";
    try {
      storageService.save(file);

      message = "Uploaded the file successfully: " + file.getOriginalFilename();
      return ResponseEntity.status(HttpStatus.OK).body(new ResponseMessage(message));
    } catch (Exception e) {
      message = "Could not upload the file: " + file.getOriginalFilename() + "!";
      return ResponseEntity.status(HttpStatus.EXPECTATION_FAILED).body(new ResponseMessage(message));
    }
  }

  @GetMapping("/files")
  public ResponseEntity<List<FileInfo>> getListFiles() {
    List<FileInfo> fileInfos = storageService.loadAll().map(path -> {
      String filename = path.getFileName().toString();
      String url = MvcUriComponentsBuilder
          .fromMethodName(FilesController.class, "getFile", path.getFileName().toString()).build().toString();

      return new FileInfo(filename, url);
    }).collect(Collectors.toList());

    return ResponseEntity.status(HttpStatus.OK).body(fileInfos);
  }

  @GetMapping("/files/{filename:.+}")
  @ResponseBody
  public ResponseEntity<Resource> getFile(@PathVariable String filename) {
    Resource file = storageService.load(filename);
    return ResponseEntity.ok()
        .header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + file.getFilename() + "\"").body(file);
  }
}

@CrossOrigin is for configuring allowed origins.
@Controller annotation is used to define a controller.
@GetMapping and @PostMapping annotation is for mapping HTTP GET & POST requests onto specific handler methods:

  • POST /upload: uploadFile()
  • GET /files: getListFiles()
  • GET /files/[filename]: getFile()

– We use @Autowired to inject implementation of FilesStorageService bean to local variable.

Configure Multipart File for Servlet

Let’s define the maximum file size that can be uploaded in application.properties as following:

spring.servlet.multipart.max-file-size=500KB
spring.servlet.multipart.max-request-size=500KB

spring.servlet.multipart.max-file-size: max file size for each request.
spring.servlet.multipart.max-request-size: max request size for a multipart/form-data.

Handle File Upload Exception

This is where we handle the case in that a request exceeds Max Upload Size. The system will throw MaxUploadSizeExceededException and we’re gonna use @ControllerAdvice with @ExceptionHandlerannotation for handling the exceptions.

exception/FileUploadExceptionAdvice.java

package com.bezkoder.spring.files.upload.exception;

import org.springframework.web.multipart.MaxUploadSizeExceededException;
import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;

import com.bezkoder.spring.files.upload.model.ResponseMessage;

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;

@ControllerAdvice
public class FileUploadExceptionAdvice extends ResponseEntityExceptionHandler {

  @ExceptionHandler(MaxUploadSizeExceededException.class)
  public ResponseEntity<ResponseMessage> handleMaxSizeException(MaxUploadSizeExceededException exc) {
    return ResponseEntity.status(HttpStatus.EXPECTATION_FAILED).body(new ResponseMessage("File too large!"));
  }
}

Initialize Storage

We need to run init() method of FilesStorageService (and also deleteAll() if necessary). So open SpringBootUploadFilesApplication.java and implement CommandLineRunner for run() method like this:

package com.bezkoder.spring.files.upload;

import javax.annotation.Resource;

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

import com.bezkoder.spring.files.upload.service.FilesStorageService;

@SpringBootApplication
public class SpringBootUploadFilesApplication implements CommandLineRunner {
  @Resource
  FilesStorageService storageService;

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

  @Override
  public void run(String... arg) throws Exception {
    storageService.deleteAll();
    storageService.init();
  }
}

Run & Test

Run Spring Boot application with command: mvn spring-boot:run.
Refresh the project directory and you will see uploads folder inside it.

Let’s use Postman to make some requests.

– Upload some files:

spring-boot-multipart-file-upload-example-upload-files

– Upload a file with size larger than max file size (500KB):

spring-boot-multipart-file-upload-example-upload-exceed-max-size

– Check uploads folder:

spring-boot-multipart-file-upload-example-uploads-folder

– Retrieve list of Files’ information:

spring-boot-multipart-file-upload-example-get-list-files

– Now you can download any file from one of the paths above.
For example: http://localhost:8080/files/bezkoder.png.

Conclusion

Today we’ve learned how to create Spring Boot Application to upload multipart files and get files’ information with static folder via Restful API.

Following tutorials explain how to build Front-end Apps to work with our Spring Boot Server:
Angular 8 Client / Angular 10 Client
Vue Client / Vuetify Client
React Client / React Hooks Client

For multiple Files at once:
How to upload multiple files in Java Spring Boot

You can also know way to upload an Excel/CSV file and store the content in MySQL database with the post:
Spring Boot: Upload/Import Excel file data into MySQL Database
Spring Boot: Upload/Import CSV file data into MySQL Database

If you want to store files in database like this:
spring-boot-upload-files-to-database-table-files

You can find instruction at:
Spring Boot Upload/Download File to/from Database example

Happy Learning! See you again.

Further Reading

Source Code

You can find the complete source code for this tutorial on Github.

33 thoughts to “Spring Boot Multipart File upload example”

  1. But the methode, delete All will cause deleting the uploaded files also and if we delete it… we will have a command liner problem caused of this action, so how to avoid this problem? because I need a solution that maintain the creation of the directory automatically and also maintaining the old uploaded files

      1. Hello !

        First of all thanks a lot for the post. Could you also provide us an example in Spring of how to upload a file and store it in memory? Or maybe if you can guide us on the internet on how to find it.
        Thank you !

  2. It’s not working for me can you help me.

    [org.springframework.web.multipart.support.MissingServletRequestPartException: Required request part ‘file’ is not present]

    1. Hi, you can use @RequestParam MultipartFile[] file.
      I will write the tutorial when having time. Thanks for your suggestion.

    2. Hi, I’ve just written a new Tutorial for Multiple Files Upload at once. You can find it in the Conclusion section 🙂

  3. I get a “400 Bad Request” when testing the api with post man but i did everything like you ,it worked at the start but now it doesn’t any help please.

  4. Hi !! I see that the files are saved in a project directory. Is there any chance to save them in a sql database?

  5. hi, thk u very muth for this tutoriel
    i use the DataBAse postresql , in postman i try insert with post request ( my class with many attributes name, age , … and this for file upload) that’s ok response : 200 in postman
    but i not find the file in DB ?? (base empty) however the request is ok

  6. i am getting 400 bad request, used the same input params in the form data for the body section .

    can you shares the headers you are using? can we leave them as default ?

      1. yes
        i have that in my headers, I wish I could share my screenshot here, still getting 400 bad request “The request cannot be fullfilled due to bad syntax”

  7. When hitting postman request when you enter key in body -> form/data and hover over inside key box then you will see File option in addition to text.
    Select File option and choose a file and run the program it will work as expected.

  8. Whenever I close Eclipse or reload the service in which I created the file uploads, the file becomes empty.. why is that ?? Also my friend tried your method too and she dosn’t have the same issue. Why in your opinion the uploads file becomes empty?

    1. Hi, look at SpringBootUploadFilesApplication.java, in run() method, we call storageService.deleteAll(); for deleting all stored files.
      So you only need to remove the line. 🙂

  9. Hi,

    First of all thanks for sharing nice and easy tutorial.
    Only request I have is to add security prospect in it like validations, check file format etc.
    When we upload the files from the internet these are the basic things we required now.

    Thanks,
    Atul

  10. Thank you very much for your reply 🙂
    I am also trying to display a list of images (not only their names , the image it self ) from database with their path saved in uploads file (I kind of combined your tutorial with another to make the Url, name and size saved in database) and I tried so many spring boot and angular tutoriels that would go with this tutoriel but in vain .. so do you have an idea or a tutoriel that shows how to display a list of images from database and uploads ?

    1. Hi, maybe you want to display a list of images (not only their names , the image it self ) in uploads folder with their information (Url, name and size) saved in database?

      I will write the tutorial when having time. 🙂

  11. Invalid CORS request is comming in Postman, I enabled postman interceptor + enabled allow origin header but still facing same issue for POST req , working fine for Get request

  12. Whenever I try to remove the deleteAll() method from main function, I get the below error
    java.lang.IllegalStateException: Failed to execute CommandLineRunner
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:798) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE]
    at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:779) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:322) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE]
    at com.servyces.churchportal.ChurchportalApplication.main(ChurchportalApplication.java:16) ~[classes/:na]

    With deleteAll() it works perfectly, but without it, it throws the said error. Can you help me resolve this?

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