com.google.appengine.api.blobstore
Interface BlobstoreService

public interface BlobstoreService

BlobstoreService allows you to manage the creation and serving of large, immutable blobs to users.

Field Summary

static int

MAX_BLOB_FETCH_SIZE

Method Summary

java.lang.String	createUploadUrl(java.lang.String successPath) Create an absolute URL that can be used by a user to asynchronously upload a large blob.
void	delete(BlobKey... blobKeys) Permanently deletes the specified blobs.
byte[]	fetchData(BlobKey blobKey, long startIndex, long endIndex) Get fragment from specified blob.
ByteRange	getByteRange(HttpServletRequest request) Get byte range from the request.
java.util.Map<java.lang.String,BlobKey>	getUploadedBlobs(HttpServletRequest request) Returns the BlobKey for any files that were uploaded.
void	serve(BlobKey blobKey, ByteRange byteRange, HttpServletResponse response) Arrange for the specified blob to be served as the response content for the current request.
void	serve(BlobKey blobKey, HttpServletResponse response) Arrange for the specified blob to be served as the response content for the current request.
void	serve(BlobKey blobKey, java.lang.String rangeHeader, HttpServletResponse response) Arrange for the specified blob to be served as the response content for the current request.

Field Detail

MAX_BLOB_FETCH_SIZE

static final int MAX_BLOB_FETCH_SIZE

See Also:

Constant Field Values

Method Detail

createUploadUrl

java.lang.String createUploadUrl(java.lang.String successPath)

Create an absolute URL that can be used by a user to asynchronously upload a large blob. Upon completion of the upload, a callback is made to the specified URL.

Parameters:

successPath - A relative URL which will be invoked after the user successfully uploads a blob.

Throws:

java.lang.IllegalArgumentException - If successPath was not valid.

BlobstoreFailureException - If an error occurred while communicating with the blobstore.

serve

void serve(BlobKey blobKey,
           HttpServletResponse response)
           throws java.io.IOException

Arrange for the specified blob to be served as the response content for the current request. response should be uncommitted before invoking this method, and should be assumed to be committed after invoking it. Any content written before calling this method will be ignored. You may, however, append custom headers before or after calling this method.

Range header will be automatically translated from the Content-Range header in the response.

Parameters:

blobKey - Blob-key to serve in response.

response - HTTP response object.

Throws:

java.io.IOException - If an I/O error occurred.

java.lang.IllegalStateException - If response was already committed.

serve

void serve(BlobKey blobKey,
           ByteRange byteRange,
           HttpServletResponse response)
           throws java.io.IOException

Arrange for the specified blob to be served as the response content for the current request. response should be uncommitted before invoking this method, and should be assumed to be committed after invoking it. Any content written before calling this method will be ignored. You may, however, append custom headers before or after calling this method.

This method will set the App Engine blob range header to serve a byte range of that blob.

Parameters:

blobKey - Blob-key to serve in response.

byteRange - Byte range to serve in response.

response - HTTP response object.

Throws:

java.io.IOException - If an I/O error occurred.

java.lang.IllegalStateException - If response was already committed.

serve

void serve(BlobKey blobKey,
           java.lang.String rangeHeader,
           HttpServletResponse response)
           throws java.io.IOException

Arrange for the specified blob to be served as the response content for the current request. response should be uncommitted before invoking this method, and should be assumed to be committed after invoking it. Any content written before calling this method will be ignored. You may, however, append custom headers before or after calling this method.

This method will set the App Engine blob range header to the content specified.

Parameters:

blobKey - Blob-key to serve in response.

rangeHeader - Content for range header to serve.

response - HTTP response object.

Throws:

java.io.IOException - If an I/O error occurred.

java.lang.IllegalStateException - If response was already committed.

getByteRange

ByteRange getByteRange(HttpServletRequest request)

Get byte range from the request.

Parameters:

request - HTTP request object.

Returns:

Byte range as parsed from the HTTP range header. null if there is no header.

Throws:

RangeFormatException - Unable to parse header because of invalid format.

UnsupportedRangeFormatException - Header is a valid HTTP range header, the specific form is not supported by app engine. This includes unit types other than "bytes" and multiple ranges.

delete

void delete(BlobKey... blobKeys)

Permanently deletes the specified blobs. Deleting unknown blobs is a no-op.

Throws:

BlobstoreFailureException - If an error occurred while communicating with the blobstore.

getUploadedBlobs

java.util.Map<java.lang.String,BlobKey> getUploadedBlobs(HttpServletRequest request)

Returns the BlobKey for any files that were uploaded. This method should only be called from within a request served by the destination of a createUploadUrl call.

Throws:

java.lang.IllegalStateException - If not called from a blob upload callback request.

fetchData

byte[] fetchData(BlobKey blobKey,
                 long startIndex,
                 long endIndex)

Get fragment from specified blob.

Parameters:

blobKey - Blob-key from which to fetch data.

startIndex - Start index of data to fetch.

endIndex - End index (inclusive) of data to fetch.

Throws:

java.lang.IllegalArgumentException - If blob not found, indexes are negative, indexes are inverted or fetch size is too large.

java.lang.SecurityException - If the application does not have acces to the blob.

BlobstoreFailureException - If an error occurred while communicating with the blobstore.