Question

我有一个方法必须从用户上传的原始文件中创建一个zip和mat文件。所以我决定只存储原始文件，然后在异步任务中我想创建另外两个文件。我读到@Async注释有两个限制： 1）仅限公共方法 2）@Async方法必须位于与调用者类相关的differet对象中。所以我创建了一个新类并将其放入我的异步方法但它仍然无法正常工作。这是调用异步方法的类：

@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)

是异步方法，它在这里：

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();
    }

}

我尝试了但@EnableAsync调用者类和confiuration类，但它不起作用。我的代码有什么问题？静态方法？感谢

Answer 1

您需要以下内容：

$ node index.js ************** ERROR ************** b is not defined ReferenceError: b is not defined at Object.<anonymous> (path/index.js:11:9) at Module._compile (module.js:434:26) at Object.Module._extensions..js (module.js:452:10) at Module.load (module.js:355:32) at Function.Module._load (module.js:310:12) at Function.Module.runMain (module.js:475:10) at startup (node.js:117:18) at node.js:951:3在配置类上启用Spring中的异步处理。

@EnableAsync

@Service或@Component将其作为Spring组件发现。
更改您的ZipAndMat方法，使其不是静态。
在createZipAndMat中自动装配这个新的Spring组件，如下所示：

FleetAcquisitionServicesImpl

然后，您不需要调用静态方法@Autowired private ZipAndMat zipAndMat;，而是需要在自动装配的spring组件实例上调用它，如下所示：

ZipAndMat.createZipAndMat(carPath,fileName);

Answer 2

您需要执行以下操作才能启用异步

1）。 @服务公共类ZipAndMat ......

2。）调用者类应该使用@EnableAsync

启用异步调用

@EnableAsync @服务公共类FleetAcquisitionServicesImpl实现FleetAcquisitionServices

请点击此链接了解更多详情 https://spring.io/guides/gs/async-method/

@Async Spring注释不起作用

2 个答案: