com.azure.storage.blob.specialized

Class AppendBlobClient

java.lang.Object

com.azure.storage.blob.specialized.BlobClientBase

com.azure.storage.blob.specialized.AppendBlobClient

public final class AppendBlobClient
extends BlobClientBase

Client to an append blob. It may only be instantiated through a SpecializedBlobClientBuilder or via the method BlobClient.getAppendBlobClient(). This class does not hold any state about a particular blob, but is instead a convenient way of sending appropriate requests to the resource on the service.

This client contains operations on a blob. Operations on a container are available on BlobContainerClient, and operations on the service are available on BlobServiceClient.

Please refer to the Azure Docs for more information.

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAX_APPEND_BLOCK_BYTES Indicates the maximum number of bytes that can be sent in a call to appendBlock.
static int	MAX_BLOCKS Indicates the maximum number of blocks allowed in an append blob.

Method Summary

Modifier and Type	Method and Description
AppendBlobItem	appendBlock(InputStream data, long length) Commits a new block of data to the end of the existing append blob.
AppendBlobItem	appendBlockFromUrl(String sourceUrl, BlobRange sourceRange) Commits a new block of data from another blob to the end of this append blob.
Response<AppendBlobItem>	appendBlockFromUrlWithResponse(String sourceUrl, BlobRange sourceRange, byte[] sourceContentMd5, AppendBlobRequestConditions destAccessConditions, BlobRequestConditions sourceAccessConditions, Duration timeout, Context context) Commits a new block of data from another blob to the end of this append blob.
Response<AppendBlobItem>	appendBlockWithResponse(InputStream data, long length, byte[] contentMd5, AppendBlobRequestConditions appendBlobRequestConditions, Duration timeout, Context context) Commits a new block of data to the end of the existing append blob.
AppendBlobItem	create() Creates a 0-length append blob.
AppendBlobItem	create(boolean overwrite) Creates a 0-length append blob.
Response<AppendBlobItem>	createWithResponse(BlobHttpHeaders headers, Map<String,String> metadata, BlobRequestConditions accessConditions, Duration timeout, Context context) Creates a 0-length append blob.
BlobOutputStream	getBlobOutputStream() Creates and opens an output stream to write data to the append blob.
BlobOutputStream	getBlobOutputStream(AppendBlobRequestConditions accessConditions) Creates and opens an output stream to write data to the append blob.

Methods inherited from class com.azure.storage.blob.specialized.BlobClientBase

abortCopyFromUrl, abortCopyFromUrlWithResponse, beginCopy, beginCopy, copyFromUrl, copyFromUrlWithResponse, createSnapshot, createSnapshotWithResponse, delete, deleteWithResponse, download, downloadToFile, downloadToFileWithResponse, downloadWithResponse, exists, existsWithResponse, getAccountInfo, getAccountInfoWithResponse, getAccountName, getBlobName, getBlobUrl, getContainerName, getCustomerProvidedKey, getHttpPipeline, getProperties, getPropertiesWithResponse, getServiceVersion, getSnapshotClient, getSnapshotId, isSnapshot, openInputStream, openInputStream, setAccessTier, setAccessTierWithResponse, setHttpHeaders, setHttpHeadersWithResponse, setMetadata, setMetadataWithResponse, undelete, undeleteWithResponse

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAX_APPEND_BLOCK_BYTES

public static final int MAX_APPEND_BLOCK_BYTES

Indicates the maximum number of bytes that can be sent in a call to appendBlock.

See Also:

Constant Field Values

MAX_BLOCKS

public static final int MAX_BLOCKS

Indicates the maximum number of blocks allowed in an append blob.

See Also:

Constant Field Values

Method Detail

getBlobOutputStream

public BlobOutputStream getBlobOutputStream()

Creates and opens an output stream to write data to the append blob. If the blob already exists on the service, it will be overwritten.

Returns:

A BlobOutputStream object used to write data to the blob.

Throws:

BlobStorageException - If a storage service error occurred.

getBlobOutputStream

public BlobOutputStream getBlobOutputStream(AppendBlobRequestConditions accessConditions)

Creates and opens an output stream to write data to the append blob. If the blob already exists on the service, it will be overwritten.

Parameters:

accessConditions - A BlobRequestConditions object that represents the access conditions for the blob.

Returns:

A BlobOutputStream object used to write data to the blob.

Throws:

BlobStorageException - If a storage service error occurred.

create

public AppendBlobItem create()

Creates a 0-length append blob. Call appendBlock to append data to an append blob. By default this method will not overwrite an existing blob.

Code Samples

System.out.printf("Created AppendBlob at %s%n", client.create().getLastModified());

Returns:

The information of the created appended blob.

create

public AppendBlobItem create(boolean overwrite)

Creates a 0-length append blob. Call appendBlock to append data to an append blob.

Code Samples

boolean overwrite = false; // Default value
System.out.printf("Created AppendBlob at %s%n", client.create(overwrite).getLastModified());

Parameters:

overwrite - Whether or not to overwrite, should data exist on the blob.

Returns:

The information of the created appended blob.

createWithResponse

public Response<AppendBlobItem> createWithResponse(BlobHttpHeaders headers,
                                                   Map<String,String> metadata,
                                                   BlobRequestConditions accessConditions,
                                                   Duration timeout,
                                                   Context context)

Creates a 0-length append blob. Call appendBlock to append data to an append blob.

Code Samples

BlobHttpHeaders headers = new BlobHttpHeaders()
    .setContentType("binary")
    .setContentLanguage("en-US");
Map<String, String> metadata = Collections.singletonMap("metadata", "value");
BlobRequestConditions accessConditions = new BlobRequestConditions()
    .setLeaseId(leaseId)
    .setIfUnmodifiedSince(OffsetDateTime.now().minusDays(3));
Context context = new Context("key", "value");

System.out.printf("Created AppendBlob at %s%n",
    client.createWithResponse(headers, metadata, accessConditions, timeout, context).getValue().getLastModified());

Parameters:

headers - BlobHttpHeaders

metadata - Metadata to associate with the blob.

accessConditions - BlobRequestConditions

timeout - An optional timeout value beyond which a RuntimeException will be raised.

context - Additional context that is passed through the Http pipeline during the service call.

Returns:

A Response whose value contains the created appended blob.

appendBlock

public AppendBlobItem appendBlock(InputStream data,
                                  long length)

Commits a new block of data to the end of the existing append blob.

Note that the data passed must be replayable if retries are enabled (the default). In other words, the Flux must produce the same data each time it is subscribed to.

Code Samples

System.out.printf("AppendBlob has %d committed blocks%n",
    client.appendBlock(data, length).getBlobCommittedBlockCount());

Parameters:

data - The data to write to the blob.

length - The exact length of the data. It is important that this value match precisely the length of the data emitted by the Flux.

Returns:

The information of the append blob operation.

appendBlockWithResponse

public Response<AppendBlobItem> appendBlockWithResponse(InputStream data,
                                                        long length,
                                                        byte[] contentMd5,
                                                        AppendBlobRequestConditions appendBlobRequestConditions,
                                                        Duration timeout,
                                                        Context context)

Commits a new block of data to the end of the existing append blob.

Note that the data passed must be replayable if retries are enabled (the default). In other words, the Flux must produce the same data each time it is subscribed to.

Code Samples

byte[] md5 = MessageDigest.getInstance("MD5").digest("data".getBytes(StandardCharsets.UTF_8));
AppendBlobRequestConditions accessConditions = new AppendBlobRequestConditions()
    .setAppendPosition(POSITION)
    .setMaxSize(maxSize);
Context context = new Context("key", "value");

System.out.printf("AppendBlob has %d committed blocks%n",
    client.appendBlockWithResponse(data, length, md5, accessConditions, timeout, context)
        .getValue().getBlobCommittedBlockCount());

Parameters:

data - The data to write to the blob. Note that this Flux must be replayable if retries are enabled (the default). In other words, the Flux must produce the same data each time it is subscribed to.

length - The exact length of the data. It is important that this value match precisely the length of the data emitted by the Flux.

contentMd5 - An MD5 hash of the block content. This hash is used to verify the integrity of the block during transport. When this header is specified, the storage service compares the hash of the content that has arrived with this header value. Note that this MD5 hash is not stored with the blob. If the two hashes do not match, the operation will fail.

appendBlobRequestConditions - AppendBlobRequestConditions

timeout - An optional timeout value beyond which a RuntimeException will be raised.

context - Additional context that is passed through the Http pipeline during the service call.

Returns:

A Response whose value contains the append blob operation.

Throws:

UnexpectedLengthException - when the length of data does not match the input length.

NullPointerException - if the input data is null.

appendBlockFromUrl

public AppendBlobItem appendBlockFromUrl(String sourceUrl,
                                         BlobRange sourceRange)

Commits a new block of data from another blob to the end of this append blob.

Code Samples

System.out.printf("AppendBlob has %d committed blocks%n",
    client.appendBlockFromUrl(sourceUrl, new BlobRange(offset, count)).getBlobCommittedBlockCount());

Parameters:

sourceUrl - The url to the blob that will be the source of the copy. A source blob in the same storage account can be authenticated via Shared Key. However, if the source is a blob in another account, the source blob must either be public or must be authenticated via a shared access signature. If the source blob is public, no authentication is required to perform the operation.

sourceRange - The source BlobRange to copy.

Returns:

The information of the append blob operation.

appendBlockFromUrlWithResponse

public Response<AppendBlobItem> appendBlockFromUrlWithResponse(String sourceUrl,
                                                               BlobRange sourceRange,
                                                               byte[] sourceContentMd5,
                                                               AppendBlobRequestConditions destAccessConditions,
                                                               BlobRequestConditions sourceAccessConditions,
                                                               Duration timeout,
                                                               Context context)

Commits a new block of data from another blob to the end of this append blob.

Code Samples

AppendBlobRequestConditions appendBlobRequestConditions = new AppendBlobRequestConditions()
    .setAppendPosition(POSITION)
    .setMaxSize(maxSize);

BlobRequestConditions modifiedAccessConditions = new BlobRequestConditions()
    .setIfUnmodifiedSince(OffsetDateTime.now().minusDays(3));

Context context = new Context("key", "value");

System.out.printf("AppendBlob has %d committed blocks%n",
    client.appendBlockFromUrlWithResponse(sourceUrl, new BlobRange(offset, count), null,
        appendBlobRequestConditions, modifiedAccessConditions, timeout,
        context).getValue().getBlobCommittedBlockCount());

Parameters:

sourceUrl - The url to the blob that will be the source of the copy. A source blob in the same storage account can be authenticated via Shared Key. However, if the source is a blob in another account, the source blob must either be public or must be authenticated via a shared access signature. If the source blob is public, no authentication is required to perform the operation.

sourceRange - BlobRange

sourceContentMd5 - An MD5 hash of the block content from the source blob. If specified, the service will calculate the MD5 of the received data and fail the request if it does not match the provided MD5.

destAccessConditions - AppendBlobRequestConditions

sourceAccessConditions - BlobRequestConditions

timeout - An optional timeout value beyond which a RuntimeException will be raised.

context - Additional context that is passed through the Http pipeline during the service call.

Returns:

The information of the append blob operation.