public class BlobInfoFactory
extends java.lang.Object
BlobInfoFactory
provides a trivial interface for retrieving
BlobInfo
metadata.
BlobInfo metadata is stored in read-only __BlobInfo__
entities in the datastore. This class provides an easy way to
access these entities. For more complex queries, you can use the
datastore directly.
Modifier and Type | Field and Description |
---|---|
static java.lang.String |
CONTENT_TYPE |
static java.lang.String |
CREATION |
static java.lang.String |
FILENAME |
static java.lang.String |
GS_OBJECT_NAME |
static java.lang.String |
KIND |
static java.lang.String |
MD5_HASH |
static java.lang.String |
SIZE |
Constructor and Description |
---|
BlobInfoFactory()
Creates a
BlobInfoFactory that uses the default
implementation of DatastoreService . |
BlobInfoFactory(DatastoreService datastoreService)
Creates a
BlobInfoFactory with the specified
implementation of DatastoreService . |
Modifier and Type | Method and Description |
---|---|
BlobInfo |
createBlobInfo(Entity entity)
|
BlobInfo |
loadBlobInfo(BlobKey blobKey)
Loads the
BlobInfo metadata for blobKey . |
java.util.Iterator<BlobInfo> |
queryBlobInfos()
|
java.util.Iterator<BlobInfo> |
queryBlobInfosAfter(BlobKey previousBlob)
Queries for
BlobInfo instances, beginning at the blob
following previousBlob in lexicographic order. |
public static final java.lang.String KIND
public static final java.lang.String CONTENT_TYPE
public static final java.lang.String CREATION
public static final java.lang.String FILENAME
public static final java.lang.String SIZE
public static final java.lang.String MD5_HASH
public static final java.lang.String GS_OBJECT_NAME
public BlobInfoFactory()
BlobInfoFactory
that uses the default
implementation of DatastoreService
.public BlobInfoFactory(DatastoreService datastoreService)
BlobInfoFactory
with the specified
implementation of DatastoreService
.public java.util.Iterator<BlobInfo> queryBlobInfos()
public java.util.Iterator<BlobInfo> queryBlobInfosAfter(BlobKey previousBlob)
BlobInfo
instances, beginning at the blob
following previousBlob
in lexicographic order. If previousBlob
is null, the first blob will be returned.
This is useful for displaying discrete pages of blobs.