如何在 Java 中将图像/文件上传到 Firebase 存储？

Question

我正在开发一个功能，我需要使用 java 将图像/文件上传到 firebase 存储并将其公开为 API。我已经在 angular 4 typescript 中实现了这个功能。但是现在我需要这个方法作为 Java Rest API，这样我的同伴也可以使用相同的方法而不是编写新的方法。那么是否有任何 API 或方法可以将图像写入 firebase 存储？

Answer 1

如果 Java 项目在受信任的环境中运行（例如他们的开发机器、您控制的服务器或 Cloud Functions），他们可以使用 Firebase Admin SDK 访问 Cloud Storage。

请参阅Firebase Admin SDK documentation 了解如何开始，然后参阅Google Cloud Storage documentation for Java clients 了解更多信息。具体看看sample of uploading a file in Java：

BlobId blobId = BlobId.of("bucket", "blob_name");
BlobInfo blobInfo = BlobInfo.newBuilder(blobId).setContentType("text/plain").build();
Blob blob = storage.create(blobInfo, "Hello, Cloud Storage!".getBytes(UTF_8));

Answer 2

试试这个：

FirebaseOptions options = FirebaseOptions.builder()
                    .setCredentials(credential)
                    .setDatabaseUrl(projectUrl)
                    .setStorageBucket("YOUR BUCKET LINK")
                    .build();

    FirebaseApp fireApp = FirebaseApp.initializeApp(options);

    StorageClient storageClient = StorageClient.getInstance(fireApp);
            InputStream testFile = new FileInputStream("YOUR FILE PATH");
            String blobString = "NEW_FOLDER/" + "FILE_NAME.EXT";        

    storageClient.bucket().create(blobString, testFile , Bucket.BlobWriteOption.userProject("YOUR PROJECT ID"));

Answer 3

String blobString = DIR + fileIdWithExtension;
Blob blob = storageClient.bucket().create(blobString, file.getInputStream(), Bucket.BlobWriteOption.userProject(PROJECT_ID));

但请记住，您应该初始化 firebase。例如

   private FirebaseApp initFirebase() {
        FileInputStream serviceAccount;
        try {
            serviceAccount = new FileInputStream(fileUploadPath);
        } catch (FileNotFoundException e) {
            throw new FileStorageException(ErrorMessage.FILE_NOT_FOUND + "firebaseConfig.json");
        }
        FirebaseOptions options;
        try {
            options = new FirebaseOptions.Builder()
                    .setCredentials(GoogleCredentials.fromStream(serviceAccount))
                    .setStorageBucket(BUCKET_NAME)
                    .build();
        } catch (IOException e) {
            e.printStackTrace();
            throw new FailedToSetCredentialsException(ErrorMessage.COULD_NOT_SET_CREDENTIALS);
        }

        return FirebaseApp.initializeApp(options);
    }

Answer 4

如果你使用的是 Spring Boot，你可以试试这个：

1. 创建一个类以在您的 API 中将其公开为 Web 服务：

import com.yourcompany.yourproject.services.FirebaseFileService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

@RestController
public class ResourceController {
    @Autowired
    private FirebaseFileService firebaseFileService;
    
    @PostMapping("/api/v1/test")
    public ResponseEntity create(@RequestParam(name = "file") MultipartFile file) {
        try {
            String fileName = firebaseFileService.saveTest(file);
            // do whatever you want with that
        } catch (Exception e) {
        //  throw internal error;
        }
        return ResponseEntity.ok().build();
    }
}

1. 创建服务以将图像上传到 Firebase 存储。

@Service
public class FirebaseFileService {

    private Storage storage;

    @EventListener
    public void init(ApplicationReadyEvent event) {
        try {
            ClassPathResource serviceAccount = new ClassPathResource("firebase.json");
            storage = StorageOptions.newBuilder().
                    setCredentials(GoogleCredentials.fromStream(serviceAccount.getInputStream())).
                    setProjectId("YOUR_PROJECT_ID").build().getService();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    public String saveTest(MultipartFile file) throws IOException{
        String imageName = generateFileName(file.getOriginalFilename());
        Map<String, String> map = new HashMap<>();
        map.put("firebaseStorageDownloadTokens", imageName);
        BlobId blobId = BlobId.of("YOUR_BUCKET_NAME", imageName);
        BlobInfo blobInfo = BlobInfo.newBuilder(blobId)
                .setMetadata(map)
                .setContentType(file.getContentType())
                .build();
        storage.create(blobInfo, file.getInputStream());
        return imageName;
    }
    
    private String generateFileName(String originalFileName) {
        return UUID.randomUUID().toString() + "." + getExtension(originalFileName);
    }

    private String getExtension(String originalFileName) {
        return StringUtils.getFilenameExtension(originalFileName);
    }
}

请注意，您需要下载 Firebase 配置文件并将其作为“firebase.json”存储在 src/main/resources 文件夹下。 https://support.google.com/firebase/answer/7015592?hl=en

另外你需要添加 Maven 依赖：

<dependency>
    <groupId>com.google.firebase</groupId>
    <artifactId>firebase-admin</artifactId>
    <version>6.14.0</version>
</dependency>