Java 为什么我的Angular Node.js应用程序使用࿽；邮递员正确上传时的符号？

我知道当我通过邮递员发布一张图片时，图片会如你所期望的那样出现。然而，当它通过我的应用程序上传时，据我所知，使用相同的标题/限定条件，图像会被切碎或转换为带有菱形问号符号的不可读格式。为什么会这样？我怎样才能防止这种情况？为什么?

HTML:

Java服务：

package inno.garage.june19.bucket;

import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.model.CannedAccessControlList;
import com.amazonaws.services.s3.model.DeleteObjectRequest;
import com.amazonaws.services.s3.model.PutObjectRequest;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import javax.annotation.PostConstruct;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Date;

@Service
public class AmazonClient {

    private AmazonS3 s3client;

    @Value("${amazonProperties.endpointUrl}")
    private String endpointUrl;
    @Value("${amazonProperties.bucketName}")
    private String bucketName;
    @Value("${amazonProperties.accessKey}")
    private String accessKey;
    @Value("${amazonProperties.secretKey}")
    private String secretKey;

    @PostConstruct
    private void initializeAmazon() {
        AWSCredentials credentials = new BasicAWSCredentials(this.accessKey, this.secretKey);
        this.s3client = new AmazonS3Client(credentials);
    }

    public String uploadFile(MultipartFile multipartFile) {
        String fileUrl = "";
        try {
            File file = convertMultiPartToFile(multipartFile);
            String fileName = generateFileName(multipartFile);
            fileUrl = endpointUrl + "/" + bucketName + "/" + fileName;
            uploadFileTos3bucket(fileName, file);
            file.delete();
        } catch (Exception e) {
           e.printStackTrace();
        }
        return fileUrl;
    }

    private File convertMultiPartToFile(MultipartFile file) throws IOException {
        File convFile = new File(file.getOriginalFilename());
        FileOutputStream fos = new FileOutputStream(convFile);
        fos.write(file.getBytes());
        fos.close();
        return convFile;
    }

    private String generateFileName(MultipartFile multiPart) {
        return new Date().getTime() + "-" + multiPart.getOriginalFilename().replace(" ", "_");
    }

    private void uploadFileTos3bucket(String fileName, File file) {
        s3client.putObject(new PutObjectRequest(bucketName, fileName, file)
                .withCannedAcl(CannedAccessControlList.PublicRead));
    }

    public String deleteFileFromS3Bucket(String fileUrl) {
        String fileName = fileUrl.substring(fileUrl.lastIndexOf("/") + 1);
        s3client.deleteObject(new DeleteObjectRequest(bucketName, fileName));
        return "Successfully deleted";
    }

}

---

您能否查看浏览器的开发工具并打开“网络”选项卡，告诉我们您在发布图像时看到了什么？比如页眉、正文等？当我点击“编辑并重新发送”按钮时：谢谢你看这个。我已经在这个问题上工作了大约一个星期了。这一定是有原因的，为什么它在应用程序中不工作，而在邮递员中。你没有编码你的图像，是吗？您可能需要执行base64并将其发送给控制器如果我对其进行编码，那么这不是故意的。如果我在将图像发送到S3之前对其进行Base64编码，那么图像会以这种方式保存在S3中吗？在这个应用程序中，我尝试稍后在电子邮件中发送这些图像，之前我遇到了一个问题，S3将图像存储为base64编码字符串，当通过电子邮件发送图像时，它们不会显示，因为大多数电子邮件客户端不支持base64

import { Component } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';
import { ServiceContext } from 'src/app/services/service-context/service.context';

@Component ({
    selector: 'upload-images',
    templateUrl: './upload-images.html',
    styleUrls: ['./upload-images.css']
})

export class UploadImagesComponent {
    selectedFile: File = null;

    constructor(private http: HttpClient,
        private context: ServiceContext) {}

    onFileSelected(event) {
        this.selectedFile = <File>event.target.files[0];
    }

    onUpload() {
        const formData = new FormData();
        formData.append('Image', this.selectedFile, this.selectedFile.name);
        this.http.post('/storage/uploadFile', formData)
        .subscribe(res => {
            console.log(res);
        });
    }
}

package inno.garage.june19.bucket;

import inno.garage.june19.bucket.AmazonClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

@RestController
@RequestMapping("/storage")
public class BucketController {

    private AmazonClient amazonClient;

    @Autowired
    BucketController(AmazonClient amazonClient) {
        this.amazonClient = amazonClient;
    }

    @PostMapping("/uploadFile")
    public String uploadFile(@RequestPart(value = "Image") MultipartFile file) {
        return this.amazonClient.uploadFile(file);
    }

    @DeleteMapping("/deleteFile")
    public String deleteFile(@RequestPart(value = "url") String fileUrl) {
        return this.amazonClient.deleteFileFromS3Bucket(fileUrl);
    }
}

package inno.garage.june19.bucket;

import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.model.CannedAccessControlList;
import com.amazonaws.services.s3.model.DeleteObjectRequest;
import com.amazonaws.services.s3.model.PutObjectRequest;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import javax.annotation.PostConstruct;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Date;

@Service
public class AmazonClient {

    private AmazonS3 s3client;

    @Value("${amazonProperties.endpointUrl}")
    private String endpointUrl;
    @Value("${amazonProperties.bucketName}")
    private String bucketName;
    @Value("${amazonProperties.accessKey}")
    private String accessKey;
    @Value("${amazonProperties.secretKey}")
    private String secretKey;

    @PostConstruct
    private void initializeAmazon() {
        AWSCredentials credentials = new BasicAWSCredentials(this.accessKey, this.secretKey);
        this.s3client = new AmazonS3Client(credentials);
    }

    public String uploadFile(MultipartFile multipartFile) {
        String fileUrl = "";
        try {
            File file = convertMultiPartToFile(multipartFile);
            String fileName = generateFileName(multipartFile);
            fileUrl = endpointUrl + "/" + bucketName + "/" + fileName;
            uploadFileTos3bucket(fileName, file);
            file.delete();
        } catch (Exception e) {
           e.printStackTrace();
        }
        return fileUrl;
    }

    private File convertMultiPartToFile(MultipartFile file) throws IOException {
        File convFile = new File(file.getOriginalFilename());
        FileOutputStream fos = new FileOutputStream(convFile);
        fos.write(file.getBytes());
        fos.close();
        return convFile;
    }

    private String generateFileName(MultipartFile multiPart) {
        return new Date().getTime() + "-" + multiPart.getOriginalFilename().replace(" ", "_");
    }

    private void uploadFileTos3bucket(String fileName, File file) {
        s3client.putObject(new PutObjectRequest(bucketName, fileName, file)
                .withCannedAcl(CannedAccessControlList.PublicRead));
    }

    public String deleteFileFromS3Bucket(String fileUrl) {
        String fileName = fileUrl.substring(fileUrl.lastIndexOf("/") + 1);
        s3client.deleteObject(new DeleteObjectRequest(bucketName, fileName));
        return "Successfully deleted";
    }

}