¶ title: 056: Implementing a file management system in a Spring Boot application
description:
published: true
date: 2023-02-03T20:17:34.547Z
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editor: markdown
dateCreated: 2023-02-03T20:17:29.567Z
- 056: Implementación de un sistema de gestión de archivos en una aplicación Spring BootSpanish document is available
- 056: 在 Spring Boot 应用程序中实现文件管理系统Chinese Simplified document is available
- 056: Spring Boot 애플리케이션에서 파일 관리 시스템 구현Korean document is available
¶ Implementing a file management system in a Spring Boot application
Spring Boot is a Java-based framework that allows you to create stand-alone, production-grade Spring applications. In this post, we'll show you how to implement a file management system in a Spring Boot application.
¶ Prerequisites
- Some experience with Java development
- Some experience with the Spring framework
¶ Getting started
First, we'll need to create a new Spring Boot project. We can do this using the Spring Initializr.
Fill in the project details:
- Group: com.example
- Artifact: file-management-system
- Name: File Management System
- Description: A file management system implemented in Spring Boot
- Package Name: com.example.filemanagementsystem
- Type: Maven Project
- Packaging: Jar
- Java Version: 8
- Select the following dependencies:
- Web
- Thymeleaf
- Lombok
Click "Generate Project" to download the project.
¶ Project structure
Once the project has been generated, we should have the following project structure:
.
├── pom.xml
└── src
└── main
├── java
│ └── com
│ └── example
│ └── filemanagementsystem
│ ├── FileManagementSystemApplication.java
│ ├── controller
│ │ └── FileController.java
│ └── model
│ └── File.java
└── resources
├── application.properties
└── templates
└── index.html
¶ Implementing the file management system
Now that we have a basic project set up, we can start implementing our file management system.
¶ Creating the model
Our file management system will need to store information about the files that are being managed. We can do this by creating a File model:
@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class File {
private String name;
private String type;
private long size;
}
The @Data annotation from the Lombok library will generate getters, setters, and a toString method for us. The @Builder annotation will allow us to create File objects using a builder pattern. The @NoArgsConstructor and @AllArgsConstructor annotations will generate a no-args constructor and a constructor that takes all of the fields as arguments, respectively.
¶ Creating the controller
Next, we'll need to create a controller to handle requests to our file management system. We can do this by creating a FileController:
@Slf4j
@Controller
@RequestMapping("/files")
public class FileController {
@GetMapping
public String listFiles(Model model) {
// TODO: Implement this method
return "index";
}
@PostMapping
public String uploadFile(@RequestParam("file") MultipartFile file) {
// TODO: Implement this method
return "redirect:/files";
}
@GetMapping("/{id}")
public ResponseEntity<Resource> downloadFile(@PathVariable String id) {
// TODO: Implement this method
return null;
}
}
The @Slf4j annotation from the Lombok library will generate a logger for us. The @Controller annotation will mark this class as a controller. The @RequestMapping annotation will map all of the controller's methods to the /files path.
The listFiles method will handle GET requests to the /files path. It will take a Model object as a parameter and return a String that indicates which template should be rendered.
The uploadFile method will handle POST requests to the /files path. It will take a MultipartFile object as a parameter and return a String that indicates which template should be rendered.
The downloadFile method will handle GET requests to the /files/{id} path. It will take a String id as a parameter and return a ResponseEntity object that contains the file that was requested.
¶ Creating the templates
We'll need to create two templates for our file management system: one for listing files and one for uploading files. We can do this by creating an index.html file in the src/main/resources/templates directory:
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>File Management System</title>
</head>
<body>
<h1>File Management System</h1>
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Size</th>
<th></th>
</tr>
</thead>
<tbody>
<tr th:each="file : ${files}">
<td th:text="${file.name}"></td>
<td th:text="${file.type}"></td>
<td th:text="${file.size}"></td>
<td><a href="/files/[[${file.id}]]">Download</a></td>
</tr>
</tbody>
</table>
<form method="post" enctype="multipart/form-data">
<div>
<label>File:</label>
<input type="file" name="file"/>
</div>
<div>
<button type="submit">Upload</button>
</div>
</form>
</body>
</html>
This template will list all of the files that have been uploaded and provide a form for uploading new files.
¶ Configuring Spring Boot
We'll need to configure a few things in our application.properties file:
spring.thymeleaf.mode=HTML5
spring.thymeleaf.encoding=UTF-8
spring.thymeleaf.content-type=text/html
server.port=8080
The spring.thymeleaf.mode, spring.thymeleaf.encoding, and spring.thymeleaf.content-type properties will configure Thymeleaf to use HTML5, UTF-8 encoding, and text/html content type, respectively. The server.port property will configure the server to run on port 8080.
¶ Running the application
We can now run our application and test it out.
First, we'll need to build our project. We can do this by running the following command:
$ ./mvnw clean package
Next, we can run our application using the following command:
$ java -jar target/file-management-system-0.0.1-SNAPSHOT.jar
We can now access our file management system at http://localhost:8080.
¶ Conclusion
In this post, we've shown you how to implement a file management system in a Spring Boot application.