DEV Community: olnov

Storing images for your UGC app using Spring Boot and iDrive E2 S3

olnov — Sun, 13 Oct 2024 20:19:04 +0000

Hello world!

This is the second article about my experience at Makers building a social network clone. Link to the first article - https://dev.to/olnov/working-with-http-requests-in-spring-boot-5el0. The current one is dedicated to storing images for users' profiles.

Step #1. Planning.

As a part of our MVP, we decided to implement the following user story:

As a user,

I want to update my profile to include my photo,

So that other users can easily find me in the app

We also agreed on non-functional requirements.

Image files are PNG or JPG only.
File size should not exceed 1 MB.

Step #2. Analyze and Design.

We came up with different options for where to store images - remote server folder, database and object storage. Even though our application was not highly loaded, we decided to use S3 as the most appropriate solution for distributed systems. (P.S. and I had an existing iDrive e2 subscription from a previous project).

In the Database, there were only links to the public URL of iDrive storage.

Here is the DB diagram:

High-level app diagram:

Step #3. Build.

The backend part needed the following to be completed:

Add AWS SDK to the project.
Implement Image Service to work with external integration.
Implement an Image Controller to put images into a bucket using the Image Service and save the corresponding record in the DB.

In pom.xml I added the following:

       <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>s3</artifactId>
            <version>2.28.18</version>
        </dependency>

ImageService Class:

package com.makersacademy.acebook.service;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import software.amazon.awssdk.auth.credentials.AwsBasicCredentials;
import software.amazon.awssdk.auth.credentials.StaticCredentialsProvider;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.model.PutObjectRequest;
import software.amazon.awssdk.services.s3.model.PutObjectResponse;

import java.io.InputStream;
import java.net.URI;
import java.util.UUID;

@Service
public class ImageService {

    private final S3Client s3Client;

    @Value("${idrive.e2.bucket-name}")
    private String bucketName;

    @Value("${idrive.e2.endpoint}")
    private String endpoint;

    @Value("${idrive.e2.public_endpoint}")
    private String public_endpoint;

    public ImageService(@Value("${idrive.e2.access-key}") String accessKey,
                        @Value("${idrive.e2.secret-key}") String secretKey,
                        @Value("${idrive.e2.endpoint}") String endpoint) {
        AwsBasicCredentials credentials = AwsBasicCredentials.create(accessKey, secretKey);
        this.s3Client = S3Client.builder()
                .credentialsProvider(StaticCredentialsProvider.create(credentials))
                .endpointOverride(URI.create(endpoint))
                .region(Region.AWS_GLOBAL) // I dind't see exact instructions from iDrive, so I set this parameter to AWS_GLOBAL
                .build();
    }

    public String uploadImage(InputStream imageStream, long contentLength, String contentType) {
        String key = "media/" + UUID.randomUUID();

        PutObjectRequest putObjectRequest = PutObjectRequest.builder()
                .bucket(bucketName)
                .key(key)
                .contentType(contentType)
                .contentLength(contentLength) // Specify the content length
                .build();

        s3Client.putObject(putObjectRequest, software.amazon.awssdk.core.sync.RequestBody.fromInputStream(imageStream, contentLength));

        // Return the image URL
        return public_endpoint + "/" + bucketName + "/" + key;
    }
}

Idrive connection variables are stored in application.properties file:

#S3 storage settings
idrive.e2.access-key=${E2_ACCESS_KEY}
idrive.e2.secret-key=${E2_SECRET_KEY}
idrive.e2.endpoint=${E2_ENDPOINT}
idrive.e2.bucket-name=${E2_BUCKET_NAME}
idrive.e2.public_endpoint=${E2_PUBLIC_ENDPOINT}

Ok, now ImageController Class:

package com.makersacademy.acebook.controller;

import com.makersacademy.acebook.model.Post;
import com.makersacademy.acebook.repository.PostRepository;
import com.makersacademy.acebook.service.ImageService;
import com.makersacademy.acebook.model.User;
import com.makersacademy.acebook.repository.UserRepository;
import jakarta.servlet.http.HttpSession;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.view.RedirectView;

import java.io.IOException;

@Controller
public class ImageController {

    @Autowired
    private ImageService imageService;

    @Autowired
    private UserRepository userRepository;

    @Autowired
    private PostRepository postRepository;

    @PostMapping("/upload/{userId}")
    public RedirectView uploadImage(@PathVariable Long userId, @RequestParam("file") MultipartFile file) {
        try {
            // Check if the user exists
            User user = userRepository.findById(userId).orElseThrow(()->new RuntimeException("User not found"));

            // Upload image to IDrive e2 and get image URL
            String imageUrl = imageService.uploadImage(file.getInputStream(), file.getSize(), file.getContentType());

            // Save the image URL in the user's profile
            user.setUser_photo(imageUrl);
            userRepository.save(user);

            return new RedirectView("/media/"+userId);

        } catch (IOException e) {
            throw new RuntimeException("Error uploading file:"+e.getMessage());
        }
    }

    @PostMapping("/upload/post")
    public RedirectView uploadImageAsPost(@RequestParam("file") MultipartFile file, HttpSession session){
        try {
            Long userId = (Long) session.getAttribute("user_id");
            if (userId == null) {
                throw new RuntimeException("Not authorized");
            }

            String imageUrl = imageService.uploadImage(file.getInputStream(), file.getSize(), file.getContentType());
            User user = userRepository.findById(userId)
                    .orElseThrow(() -> new RuntimeException("User not found"));
            Post post = new Post(imageUrl,user,true);
            postRepository.save(post);
            return new RedirectView("/");
        } catch (IOException e) {
            throw new RuntimeException("Error uploading file:"+e.getMessage());
        }
    }
}

On the front end to upload the profile image I added the following:

<div class="mb-3">
     <form id="image-form" th:action="@{/api/images/upload/{id}(id=${user.id})}" method="post"
                           enctype="multipart/form-data">
      <"formFile" class="form-label btn btn-primary">Upload Image</label>
      <input class="form-control" type="file" name="file" id="formFile" accept=".jpg,.jpeg,.png"
                           onchange="autoSubmitImage()" hidden/>
      </form>
 </div>

 <script th:inline="javascript">
    /*<![CDATA[*/
        const autoSubmitImage = ()=> {
          document.getElementById("image-form").submit();
        }
    /*]]>*/
</script>

And the result.

This is it.

Cheers!

Working with HTTP requests in Spring Boot

olnov — Sun, 06 Oct 2024 13:31:07 +0000

Hello world!
The main goal of this article is to help beginner developers handle HTTP requests in Spring Boot.

💡In the examples I do not cover all the code required for the MVC app, just some parts to demonstrate the difference in data processing.

Recently, I’ve been working on an engineering project with other students in my class. It introduced us to a new technology stack, as we were required to build upon an “old” codebase. The codebase included Java, Spring Boot, and Thymeleaf. The project's aim was to create a clone of a popular social network.
The core functionality was fairly typical: users can create posts, and others can comment on or like those posts.
To add some visual dynamism, we decided to combine Thymeleaf with JavaScript. This way, when a post is displayed on the page, users can click to like or comment, and the changes will be processed in the back end. At this point, we needed a JavaScript function to send requests to the server for all the standard CRUD operations.
The question was: how do we properly pass data to the server using POST, PUT, or DELETE methods? GET is more or less clear, so I skip examples with GET.
Here are the possible ways.

URL Parameters (PathVariable)

URL Example: HTTP://myapp.com/posts/1

Suitable for: DELETE, PUT

Cases: You work with a specific entity on a back end - a single post in my examples.

Annotation Example:

@DeleteMapping("/posts/{post_id}")
public ResponseEntity<String> deletePost(@PathVariable("post_id") Long post_id) {
        // Some logic here...
        return ResponseEntity.ok("Deleted successfully");
    }

Example of a corresponding JS code:

 // Some pre-logic here to pass postId to the function, 
// or you can use const deletePost = async(postId)=>{} to pass postId directly
const deletePost = async () => {
    // Some pre-checks and error handling go here...
    const requestOption = {
        method:'DELETE',
        headers:{
            'Content-type':'application/json'
        }
    };
    await fetch(`/posts/${postId}`, requestOptions);
    // Some post-checks and error handling go here...
}

Form data (RequestParam)

URL Example: HTTP://myapp.com/posts or HTTP://myapp.com/posts/1 for editing

Suitable for: PUT, POST

Cases: You are creating or updating an entity with one or two parameters. In my example, it’s a post content (a text message).

Annotation Example:

@PutMapping("/posts/{post_id}")
    public ResponseEntity<String> editPost(@PathVariable("post_id") Long post_id, @RequestParam("content") String content) {
        // Some logic goes here...
        return ResponseEntity.ok("Post updated successfully");
    }

Example of a corresponding JS code:

// Some pre-logic here to pass postId and content to the function, 
// or you can use const deletePost = async(postId, updatedContent)=>{} to pass 
// them directly directly
const updatePost = async ()=> {
    // Some pre-checks and error handling go here...
    const formData = new FormData();
    formData.append("content",updatedContent);
    requestOptions = {
        method:'PUT',
        body: formData
    };
    await fetch(`/posts/${postId}`,requestOptions);
    // Some post-checks and error handling go here...
}

JSON Body (RequestBody)

Suitable for: PUT, POST

Cases: You are creating or updating a complex entity (e.g. object with 3 or more parameters).

Annotation Example:

@PutMapping("/posts/{post_id}")
    public ResponseEntity<String> editPost(@PathVariable("post_id") Long post_id, @RequestBody Post post) {
        // Some logic goes here...
        // It requires the whole object to be passed. 
        // After that it's possible to access values via getters of your object's model
        return ResponseEntity.ok("Post updated successfully");
    }

Example of a corresponding JS code:

const updatePost = async ()=> {
    // Some pre-checks and error handling go here...
    requestOptions = {
        method:'PUT',
        headers: {
            'Content-type':'application/json'
        },
        body: JSON.stringify({'content':updatedContent})
    };
    await fetch(`/posts/${postId}`,requestOptions);
    // Some post-checks and error handling go here...
}

This is it. Hope it will be helpful.
Cheers!