MultipartFile – How to create Spring AngularJs MultipartFile application to download/upload files | SpringBoot + AngularJs + Bootstrap.

In the past post, we had learned how to upload MultipartFile with SpringBoot and JQuery Ajax. Today, JavaSampleApproach shows how to create a Spring AngularJs MultipartFile application to download/upload file with SpringBoot, AngularJs and Bootstrap.

Related posts:
– MultipartFile – How to create Spring Ajax MultipartFile application to download/upload files | SpringBoot + JQuery Ajax + Bootstrap
– How to integrate Http Angularjs with Spring MVC | Spring Boot
– How to integrate Angular 4 with SpringBoot Web App and SpringToolSuite
– Angular 4 – Upload/Get MultipartFile to/from Spring Boot Server

I. Technologies

– Java 8
– Maven 3.6.1
– Spring Tool Suite: Version 3.8.4.RELEASE
– Spring Boot: 1.5.4.RELEASE
– JQuery
– Bootstrap

II. Practices

Create a SpringBoot project with below structure:

Step to do:
– Create SpringBoot project
– Create Storage Service
– Implement upload controller
– Implement AngularJs App
– Create upload page
– Init Storage for File System
– Run and check results

1. Create SpringBoot project

Open Spring Tool Suite, on main menu, choose File->New->Spring Starter Project, add project info, then press Next for needed dependencies:
– For Template Engines, choose Thymeleaf.
– For Web MVC, choose Web->Web.

Press Finish, Spring Boot project will be created successfully.
Open pom.xml file to check dependencies:

	org.springframework.boot
	spring-boot-starter-thymeleaf


	org.springframework.boot
	spring-boot-starter-web

2. Create Storage Service

Create StorageService with 4 functions:
– public void store(MultipartFile file): save a file
– public Resource loadFile(String filename): load a file
– public void deleteAll(): remove all uploaded files
– public void init(): create upload directory

package com.javasampleapproach.uploadfile.storage;

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

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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 StorageService {
	
	Logger log = LoggerFactory.getLogger(this.getClass().getName());
	private final Path rootLocation = Paths.get("upload-dir");

	public void store(MultipartFile file){
		try {
            Files.copy(file.getInputStream(), this.rootLocation.resolve(file.getOriginalFilename()));
        } catch (Exception e) {
        	throw new RuntimeException("FAIL!");
        }
	}

    public Resource loadFile(String filename) {
        try {
            Path file = rootLocation.resolve(filename);
            Resource resource = new UrlResource(file.toUri());
            if(resource.exists() || resource.isReadable()) {
                return resource;
            }else{
            	throw new RuntimeException("FAIL!");
            }
        } catch (MalformedURLException e) {
        	throw new RuntimeException("FAIL!");
        }
    }
    
    public void deleteAll() {
        FileSystemUtils.deleteRecursively(rootLocation.toFile());
    }

    public void init() {
        try {
            Files.createDirectory(rootLocation);
        } catch (IOException e) {
            throw new RuntimeException("Could not initialize storage!");
        }
    }
}

3. Implement upload controller

Create a RestUploadController with 3 RequestMapping:
– @PostMapping("/api/uploadfile") is used to upload files.
– @GetMapping("/api/getallfiles") is used to get all uploaded files
– @GetMapping("/api/files/{filename:.+}") is used to download files.

package com.javasampleapproach.uploadfile.controller;

import java.util.ArrayList;
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.ResponseEntity;
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.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.mvc.method.annotation.MvcUriComponentsBuilder;

import com.javasampleapproach.uploadfile.storage.StorageService;

@RestController
@RequestMapping("/api")
public class RestUploadController {

	@Autowired
	StorageService storageService;
	
	List files = new ArrayList();

    // Multiple file upload
    @PostMapping("/uploadfile")
    public String uploadFileMulti(@RequestParam("uploadfile") MultipartFile file) throws Exception {
    	try {
			storageService.store(file);
			files.add(file.getOriginalFilename());
			return "You successfully uploaded - " + file.getOriginalFilename();
		} catch (Exception e) {
			throw new Exception("FAIL! Maybe You had uploaded the file before or the file's size > 500KB");
		}
    }
    
	@GetMapping("/getallfiles")
	public List getListFiles() {List lstFiles = new ArrayList();
		try{
			lstFiles = files.stream()
					.map(fileName -> MvcUriComponentsBuilder
							.fromMethodName(RestUploadController.class, "getFile", fileName).build().toString())
					.collect(Collectors.toList());	
		}catch(Exception e){
			throw e;
		}
		
		return lstFiles;
	}

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

Open application.properties file, configure multipart.max-file:

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

– spring.http.multipart.max-file-size: limit total file size for each request.
– spring.http.multipart.max-request-size: limit total request size for a multipart/form-data.

4. Implement AngularJs App

4.1 Create AngularJs application

Define AngularJs application in jsaApp.js file:

var jsaApp = angular.module('jsaUploadFileApp', []);

// DIRECTIVE - FILE MODEL
jsaApp.directive('fileModel', ['$parse', function ($parse) {
    return {
       restrict: 'A',
       link: function(scope, element, attrs) {
          var model = $parse(attrs.fileModel);
          var modelSetter = model.assign;
          
          element.bind('change', function(){
             scope.$apply(function(){
                modelSetter(scope, element[0].files[0]);
             });
          });
       }
    };
}]); 

Note: Angular’s ng-model can NOT bind with file input, so we need to create a custom directive fileModel for binding data.

4.2 Implement upload controller

Create uploadFileCtrl.js file to implement uploadFileController controller:

// CONTROLLER UPLOAD FILE
jsaApp.controller('uploadFileController', ['$scope', '$http', function($scope, $http){
    $scope.doUploadFile = function(){
       var file = $scope.uploadedFile;
       var url = "/api/uploadfile";
       
       var data = new FormData();
       data.append('uploadfile', file);
    
       var config = {
    	   	transformRequest: angular.identity,
    	   	transformResponse: angular.identity,
	   		headers : {
	   			'Content-Type': undefined
	   	    }
       }
       
       $http.post(url, data, config).then(function (response) {
			$scope.uploadResult=response.data;
		}, function (response) {
			$scope.uploadResult=response.data;
		});
    };
}]);

Note: with setting 'Content-Type': undefined, the browser will automatically change the Content-Type to multipart/form-data.

4.3 Implement get controller

Create a getFilesCtrl.js file to get all uploaded files:

jsaApp.controller('getFilesController', ['$scope', '$http', function($scope, $http){
    $scope.doGetFiles = function(){
       var url = "/api/getallfiles";
       $http.get(url).then(function (response) {
			$scope.lstFiles = response.data;
		}, function (response) {
			alert(response.data);
		});
    };
}]);

5. Create upload page

– Create a Controller for uploading page:

package com.javasampleapproach.uploadfile.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

@Controller
public class IndexController {

    @GetMapping("/")
    public String index() {
        return "upload";
    }

}

– Use Bootstrap to implement upload page:

    
    
    
	
	%MINIFYHTMLb35b0ffbc399569b5b3471e30697ed8420%



	

		

			

				Upload File:
				

					
				
			
			
 
			    

			      Upload
			    
			
		
		

		

			

		
	
	
	

		

			Get Files
		
		

		

			

				
{{file}}
			
		
			
	
%MINIFYHTMLb35b0ffbc399569b5b3471e30697ed8421%%MINIFYHTMLb35b0ffbc399569b5b3471e30697ed8422%%MINIFYHTMLb35b0ffbc399569b5b3471e30697ed8423%%MINIFYHTMLb35b0ffbc399569b5b3471e30697ed8424%%MINIFYHTMLb35b0ffbc399569b5b3471e30697ed8425%%MINIFYHTMLb35b0ffbc399569b5b3471e30697ed8426%

6. Init Storage for File System

In main class of the SpringBoot application, we use CommandLineRunner interface for initialize StorageService:

package com.javasampleapproach.uploadfile;

import javax.annotation.Resource;

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

import com.javasampleapproach.uploadfile.storage.StorageService;

@SpringBootApplication
public class SpringBootAngularJsMultipartFileApplication implements CommandLineRunner {

	@Resource
	StorageService storageService;
    
    public static void main(String[] args) throws Exception {
        SpringApplication.run(SpringBootAngularJsMultipartFileApplication.class, args);
    }
    
	@Override
	public void run(String... args) throws Exception {
		storageService.deleteAll();
		storageService.init();
	}

}

7. Run and check results

Build and Run the SpringBoot project with commandlines {mvn clean install, mvn spring-boot:run}

– Make a request http://localhost:8080/ :

-> See headers:

– Choose files and do Upload:

– List uploaded files:

– Click on a link to download the file:

III. Sourcecode

SpringBootAngularJSMultipartFile