@Async Spring annotation doesn't work

I have a method that must create a zip and mat file from the original file uploaded from the user. So I decided to store only the original file and then, in an async task I would like to create the other two files. I read that the @Async annotation has two limit: 1)Only on public method 2)The @Async method must be in a differet object respect the caller class. So I create a new class and put in it my async method but it still doens't work. This is the class that calls the async method:

@Service public class FleetAcquisitionServicesImpl implements FleetAcquisitionServices{ @Autowired private DatabaseAcquisitionServices databaseAcquisitionServices; @Autowired private DatabaseFleetsAndCarsServices databaseFleetsAndCarsServices; @Autowired private FleetFolderName fleetFolderName; private static final int NUMBER_OF_SHEET=4; @Override public ArrayList<String> uploadFiles(MultipartFile[] openedFiles, Integer idFleet, Integer idCar, Integer initialKm) throws FileUploadException, FileEmptyException{ ArrayList<String> filesName=new ArrayList<String>(); String fileName=null; String carPath=null; for (MultipartFile openedFile:openedFiles){ if (!openedFile.isEmpty()) { //Copy the file into path specified fileName = openedFile.getOriginalFilename(); try { //Get the path where to store the file Fleet fleet=databaseFleetsAndCarsServices.getFleetById(idFleet); Car car=databaseFleetsAndCarsServices.getCarById(idCar); carPath= fleetFolderName.createCarName(fleet, car); if (FilenameUtils.getExtension(fileName).equals("dat")){ fileName = FilenameUtils.removeExtension(fileName)+"_km"+initialKm; //write dat file openedFile.transferTo(new File(carPath +"/"+ fileName+".dat")); ZipAndMat.createZipAndMat(carPath,fileName); }else openedFile.transferTo(new File(carPath +"/"+ fileName)); } catch (Exception e) { throw new FileUploadException("you failed to upload " + fileName,e); } filesName.add(carPath +"/"+ fileName); } else { throw new FileEmptyException("your file is empty " + openedFile.getOriginalFilename()); } } return filesName; } ZipAndMat.createZipAndMat(carPath,fileName) 

is the async method and it is here:

package com.model; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; import java.util.concurrent.Future; import java.util.zip.ZipEntry; import java.util.zip.ZipOutputStream; import org.springframework.scheduling.annotation.Async; import org.springframework.scheduling.annotation.AsyncResult; import com.mathworks.toolbox.javabuilder.MWException; import dataconversion.Converter; public class ZipAndMat { @Async public static Future<String> createZipAndMat(String filePath, String fileName){ try { Thread.sleep(20000L); } catch (InterruptedException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } //Open file Path path = Paths.get(filePath, fileName + ".dat"); try { //Create zip byte[] zip = zipBytes(Files.readAllBytes(path),fileName+".dat"); Files.write(Paths.get(filePath +"/"+ fileName+".zip"), zip); //create mat file Converter objConv = new Converter(); objConv. dat2MatConversion(filePath +"/", fileName + ".dat", 0.2); } catch (IOException e) { return new AsyncResult<String>("Zip not created"); } catch (MWException e){ return new AsyncResult<String>("Mat not created"); } return new AsyncResult<String>("Zip created"); } /** * Convert a file into zip file keeping the same name * @param filename * @param input * @return * @throws IOException */ private static byte[] zipBytes( byte[] input, String filename) throws IOException { ByteArrayOutputStream baos = new ByteArrayOutputStream(); ZipOutputStream zos = new ZipOutputStream(baos); ZipEntry entry = new ZipEntry(filename); entry.setSize(input.length); zos.putNextEntry(entry); zos.write(input); zos.closeEntry(); zos.close(); return baos.toByteArray(); } } 

I tried tu but @EnableAsync both the caller class and on the confiuration class but it doesn't works. What is wrong in my code? the static method? Thanks