Examples with ReadChannel com.google.cloud.ReadChannel used on opensource projects

Example 21 with ReadChannel

use of com.google.cloud.ReadChannel in project google-cloud-java by GoogleCloudPlatform.

the class BlobSnippets method reader.

/**
 * Example of reading the blob's content through a reader.
 */
// [TARGET reader(BlobSourceOption...)]
public void reader() throws IOException {
    // [START reader]
    try (ReadChannel reader = blob.reader()) {
        ByteBuffer bytes = ByteBuffer.allocate(64 * 1024);
        while (reader.read(bytes) > 0) {
            bytes.flip();
            // do something with bytes
            bytes.clear();
        }
    }
// [END reader]
}

Example 22 with ReadChannel

use of com.google.cloud.ReadChannel in project google-cloud-java by GoogleCloudPlatform.

the class StreamObjectDownload method streamObjectDownload.

public static void streamObjectDownload(String projectId, String bucketName, String objectName, String targetFile) throws IOException {
    // The ID of your GCP project
    // String projectId = "your-project-id";
    // The ID of your GCS bucket
    // String bucketName = "your-unique-bucket-name";
    // The ID of your GCS object
    // String objectName = "your-object-name";
    // The path to the file to download the object to
    // String targetFile = "path/to/your/file";
    Path targetFilePath = Paths.get(targetFile);
    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    try (ReadChannel reader = storage.reader(BlobId.of(bucketName, objectName));
        FileChannel targetFileChannel = FileChannel.open(targetFilePath, StandardOpenOption.WRITE)) {
        ByteStreams.copy(reader, targetFileChannel);
        System.out.println("Downloaded object " + objectName + " from bucket " + bucketName + " to " + targetFile + " using a ReadChannel.");
    }
}

Example 23 with ReadChannel

use of com.google.cloud.ReadChannel in project spanner-jdbc by olavloite.

the class CloudSpannerConnection method getCredentialsFromFile.

public static GoogleCredentials getCredentialsFromFile(String credentialsPath) throws IOException {
    if (credentialsPath == null || credentialsPath.length() == 0)
        throw new IllegalArgumentException("credentialsPath may not be null or empty");
    GoogleCredentials credentials = null;
    if (credentialsPath.startsWith(GOOGLE_CLOUD_STORAGE_PREFIX)) {
        try {
            Storage storage = StorageOptions.newBuilder().build().getService();
            String bucketName = getBucket(credentialsPath);
            String blobName = getBlob(credentialsPath);
            Blob blob = storage.get(bucketName, blobName);
            ReadChannel reader = blob.reader();
            InputStream inputStream = Channels.newInputStream(reader);
            credentials = GoogleCredentials.fromStream(inputStream, CloudSpannerOAuthUtil.HTTP_TRANSPORT_FACTORY);
        } catch (Exception e) {
            throw new IllegalArgumentException("Invalid credentials path: " + credentialsPath + ". Reason: " + e.getMessage(), e);
        }
    } else {
        File credentialsFile = new File(credentialsPath);
        if (!credentialsFile.isFile()) {
            throw new IOException(String.format("Error reading credential file %s: File does not exist", credentialsPath));
        }
        try (InputStream credentialsStream = new FileInputStream(credentialsFile)) {
            credentials = GoogleCredentials.fromStream(credentialsStream, CloudSpannerOAuthUtil.HTTP_TRANSPORT_FACTORY);
        }
    }
    return credentials;
}

Example 24 with ReadChannel

use of com.google.cloud.ReadChannel in project data-transfer-project by google.

the class GoogleTempFileStore method getStream.

InputStreamWrapper getStream(UUID jobId, String keyName) {
    String blobName = getDataKeyName(jobId, keyName);
    Blob blob = bucket.get(blobName);
    ReadChannel channel = blob.reader();
    return new InputStreamWrapper(Channels.newInputStream(channel), blob.getSize());
}