o7planning

Spring Boot File Upload Example

  1. Create Spring Boot project
  2. Configure file size
  3. Form & Controller
  4. Thymeleaf Templates
  5. Run the application

1. Create Spring Boot project

OK. Project has been created.
pom.xml
<?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
      http://maven.apache.org/xsd/maven-4.0.0.xsd">
      
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.o7planning</groupId>
    <artifactId>SpringBootFileUpload</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>SpringBootFileUpload</name>
    <description>Spring Boot + File Upload Example</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.0.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </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>
            </plugin>
        </plugins>
    </build>

</project>
SpringBootFileUploadApplication.java
package org.o7planning.sbfileupload;

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

@SpringBootApplication
public class SpringBootFileUploadApplication {

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

2. Configure file size

Spring Boot has automatically configured the necessary libraries so that you can build the file upload function. The default size of the file is limited to 128KB, so you need to configure to change the value for this parameter. Add the following properties to the application.properties file.
application.properties
spring.servlet.multipart.max-file-size=5MB
spring.servlet.multipart.max-request-size=5MB
The maximum file size is 5GB.

3. Form & Controller

MyUploadForm.java
package org.o7planning.sbfileupload.form;

import org.springframework.web.multipart.MultipartFile;

public class MyUploadForm {

    private String description;

    // Upload files.
    private MultipartFile[] fileDatas;

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public MultipartFile[] getFileDatas() {
        return fileDatas;
    }

    public void setFileDatas(MultipartFile[] fileDatas) {
        this.fileDatas = fileDatas;
    }

}
MyFileUploadController.java
package org.o7planning.sbfileupload.controller;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.o7planning.sbfileupload.form.MyUploadForm;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.multipart.MultipartFile;

@Controller
public class MyFileUploadController {

   @RequestMapping(value = "/")
   public String homePage() {

      return "index";
   }

   // GET: Show upload form page.
   @RequestMapping(value = "/uploadOneFile", method = RequestMethod.GET)
   public String uploadOneFileHandler(Model model) {

      MyUploadForm myUploadForm = new MyUploadForm();
      model.addAttribute("myUploadForm", myUploadForm);

      return "uploadOneFile";
   }

   // POST: Do Upload
   @RequestMapping(value = "/uploadOneFile", method = RequestMethod.POST)
   public String uploadOneFileHandlerPOST(HttpServletRequest request, //
         Model model, //
         @ModelAttribute("myUploadForm") MyUploadForm myUploadForm) {

      return this.doUpload(request, model, myUploadForm);

   }

   // GET: Show upload form page.
   @RequestMapping(value = "/uploadMultiFile", method = RequestMethod.GET)
   public String uploadMultiFileHandler(Model model) {

      MyUploadForm myUploadForm = new MyUploadForm();
      model.addAttribute("myUploadForm", myUploadForm);

      return "uploadMultiFile";
   }

   // POST: Do Upload
   @RequestMapping(value = "/uploadMultiFile", method = RequestMethod.POST)
   public String uploadMultiFileHandlerPOST(HttpServletRequest request, //
         Model model, //
         @ModelAttribute("myUploadForm") MyUploadForm myUploadForm) {

      return this.doUpload(request, model, myUploadForm);

   }

   private String doUpload(HttpServletRequest request, Model model, //
         MyUploadForm myUploadForm) {

      String description = myUploadForm.getDescription();
      System.out.println("Description: " + description);

      // Root Directory.
      String uploadRootPath = request.getServletContext().getRealPath("upload");
      System.out.println("uploadRootPath=" + uploadRootPath);

      File uploadRootDir = new File(uploadRootPath);
      // Create directory if it not exists.
      if (!uploadRootDir.exists()) {
         uploadRootDir.mkdirs();
      }
      MultipartFile[] fileDatas = myUploadForm.getFileDatas();
      //
      List<File> uploadedFiles = new ArrayList<File>();
      List<String> failedFiles = new ArrayList<String>();

      for (MultipartFile fileData : fileDatas) {

         // Client File Name
         String name = fileData.getOriginalFilename();
         System.out.println("Client File Name = " + name);

         if (name != null && name.length() > 0) {
            try {
               // Create the file at server
               File serverFile = new File(uploadRootDir.getAbsolutePath() + File.separator + name);

               BufferedOutputStream stream = new BufferedOutputStream(new FileOutputStream(serverFile));
               stream.write(fileData.getBytes());
               stream.close();
               //
               uploadedFiles.add(serverFile);
               System.out.println("Write file: " + serverFile);
            } catch (Exception e) {
               System.out.println("Error Write file: " + name);
               failedFiles.add(name);
            }
         }
      }
      model.addAttribute("description", description);
      model.addAttribute("uploadedFiles", uploadedFiles);
      model.addAttribute("failedFiles", failedFiles);
      return "uploadResult";
   }

}

4. Thymeleaf Templates

_menu.html
<div  xmlns:th="http://www.thymeleaf.org"
   style="border:1px solid #ccc;padding:5px;">
 
   <a th:href="@{/uploadOneFile}">Upload One File</a>
   
   &nbsp;|&nbsp;
   
   <a th:href="@{/uploadMultiFile}">Upload Multi File</a>
   
   
 </div>
index.html
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">

   <head>
      <meta charset="UTF-8">
      <title>Spring Boot File Upload Example</title>
   </head>
   
   <body>
      <th:block th:include="/_menu"></th:block>
      
      <h3>Spring Boot File Upload Example</h3>
      
      <ul>
        <li><a th:href="@{/uploadOneFile}">Upload One File Example</a></li>
        <li><a th:href="@{/uploadMultiFile}">Upload Multiple Files Example</a></li>
      </ul>
      
   </body>
</html>
uploadOneFile.html
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">

   <head>
      <meta charset="UTF-8">
      <title>Upload One File</title>
   </head>
  
   <body>
      <th:block th:include="/_menu"></th:block>
      
      <h3>Upload One File:</h3>
      
      <!-- MyUploadForm -->
      
      <form th:object="${myUploadForm}" method="POST"
         action="" enctype="multipart/form-data">
         Description:
         <br>
         <input th:field="*{description}" style="width:300px;"/>                
         <br/><br/>  
         File to upload: <input th:field="*{fileDatas}" type="file"/>
         <br />  
         <input type="submit" value="Upload">
      </form>
      
   </body>
</html>
uploadMultiFile.html
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">

   <head>
      <meta charset="UTF-8">
      <title>Upload Multi File</title>
   </head>
   
   <body>
      <th:block th:include="/_menu"></th:block>
      <h3>Upload Multiple File:</h3>
      
      <!-- MyUploadForm -->
      <form th:object="${myUploadForm}" method="POST"
         action="" enctype="multipart/form-data">
         Description:
         <br>
         <input th:field="*{description}" style="width:300px;"/>                
         <br/><br/>                 
         File to upload (1): <input th:field="*{fileDatas}" type="file"/><br />      
         File to upload (2): <input th:field="*{fileDatas}" type="file"/><br />    
         File to upload (3): <input th:field="*{fileDatas}" type="file"/><br />    
         File to upload (4): <input th:field="*{fileDatas}" type="file"/><br />    
         File to upload (5): <input th:field="*{fileDatas}" type="file"/><br />    
         <input type="submit" value="Upload">
      </form>
      
   </body>
</html>
uploadResult.html
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
   <head>
      <meta charset="UTF-8">
      <title>Upload Result</title>
   </head>
   
   <body>
      <th:block th:include="/_menu"></th:block>
      
      Description: <span th:utext="${description}"></span>
      <br/>
      <h3>Uploaded Files:</h3>
      
      <ul th:each="file : ${uploadedFiles}">
         <li th:utext="${file}"></li>  
      </ul>      
      
      <h3>Failed:</h3>
      <ul th:each="file : ${failedFiles}">
         <li style="color:red;" th:utext="${file}"></li>  
      </ul>
      
   </body>
   
</html>

5. Run the application

Spring Boot Tutorials

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