java - 云存储 - 上传图像时文件的内容类型显示为数据

Question

我正在使用 Java Client Library 将图像上传到云存储图像已上传到存储桶，但当我尝试访问它们时，浏览器中显示黑屏。因此，我深入研究了图像上传到云存储后的类型。

我将从云存储下载的图片上传到 Check File Type .com 它显示文件类型为数据，MIME/类型为application/octet-stream，而不是图像

所以，我从我的电脑上传了相同的原始图像，它完美地显示图像类型为image/jpeg

这是我使用 Java 客户端库编写的代码。

HTML Form to handle the upload

<form action="/through" method="post" enctype="multipart/form-data">
<h3>Uploading File through App Engine instances to cloud storage</h3>
<label>Enter Your Team Name</label><br>
<input type="text" name="TeamName" ><br><br> 
<label>Upload Team Logo</label><br>
<input type="file" name="teamLogo" required="required"><br><br>
<input type="submit" value="Upload Team Logo">
</form>

Java code to Upload the Image

InputStream input = request.getInputStream();
ByteArrayOutputStream byteArrayStream = new ByteArrayOutputStream();
try {
  int read = input.read();
  while(read != -1) {
    byteArrayStream.write(read);
    read = input.read();
  }
catch (IOException e){
  //Handle Exception 
}

byte[] fileBytes = byteArrayStream.toByteArray();

Storage storage = null;
    try {
        FileInputStream credentialsStream = new FileInputStream("JSONFile");
        Credentials credentials = GoogleCredentials.fromStream(credentialsStream);
        storage = StorageOptions.newBuilder().setCredentials(credentials).setProjectId("myProjectID").build().getService();

    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    BlobId blobId = BlobId.of(BUCKET_NAME, USER_NAME+"TeamLogo.jpg");
    BlobInfo blobInfo = BlobInfo.newBuilder(blobId).setContentType("image/jpeg").build();
    Blob blob = storage.create(blobInfo, fileBytes);

为什么云存储无法正确检测图片类型？它对我想要显示相同图像的应用程序的其他部分产生不利影响。

更新

在同一对象的控制台中，Content-Type 显示为 image/jpeg

Answer 1

试试这个代码:

package com.example.storage;

import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import com.google.cloud.storage.Blob;
import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.BlobInfo;

import java.io.File;
import java.nio.file.Files;
public class QuickstartSample {
  public static void main(String... args) throws Exception {
    File fi = new File("source.jpg");
    Storage storage = StorageOptions.getDefaultInstance().getService();
    BlobId blobId = BlobId.of("your-bucket", "imagen.jpg");
    BlobInfo blobInfo = BlobInfo.newBuilder(blobId).setContentType("image/jpeg").build();
    Blob blob = storage.create(blobInfo, Files.readAllBytes(fi.toPath()));
    System.out.println(blob.getContentType());
  }
}

我在CheckFileType上得到了以下结果: