public
class
BackupDataInputStream
extends InputStream
java.lang.Object | ||
↳ | java.io.InputStream | |
↳ | android.app.backup.BackupDataInputStream |
Provides an InputStream
-like interface for accessing an
entity's data during a restore operation. Used by BackupHelper
classes within the BackupAgentHelper
mechanism.
When BackupHelper.restoreEntity()
is called, the current entity's header has already been read from the underlying
BackupDataInput
. The entity's key string and total data size are available
through this class's getKey()
and size()
methods, respectively.
Note: The caller should take care not to seek or close the underlying data
source, nor read more than size()
bytes from the stream.
See also:
Public methods | |
---|---|
String
|
getKey()
Report the key string associated with this entity within the backup data set. |
int
|
read()
Read one byte of entity data from the stream, returning it as an integer value. |
int
|
read(byte[] b, int offset, int size)
Read up to |
int
|
read(byte[] b)
Read enough entity data into a byte array to fill the array. |
int
|
size()
Report the total number of bytes of data available for the current entity. |
Inherited methods | |
---|---|
From
class
java.io.InputStream
| |
From
class
java.lang.Object
| |
From
interface
java.io.Closeable
| |
From
interface
java.lang.AutoCloseable
|
String getKey ()
Report the key string associated with this entity within the backup data set.
Returns | |
---|---|
String |
The key string for this entity, equivalent to calling
getKey() on the underlying BackupDataInput .
|
int read ()
Read one byte of entity data from the stream, returning it as
an integer value. If more than size()
bytes of data
are read from the stream, the output of this method is undefined.
Returns | |
---|---|
int |
The byte read, or undefined if the end of the stream has been reached. |
Throws | |
---|---|
IOException |
int read (byte[] b, int offset, int size)
Read up to size
bytes of data into a byte array, beginning at position
offset
within the array.
Parameters | |
---|---|
b |
byte :
Byte array into which the data will be read |
offset |
int :
The data will be stored in b beginning at this index
within the array. |
size |
int :
The number of bytes to read in this operation. If insufficient
data exists within the entity to fulfill this request, only as much data
will be read as is available. |
Returns | |
---|---|
int |
The number of bytes of data read, or zero if all of the entity's data has already been read. |
Throws | |
---|---|
IOException |
int read (byte[] b)
Read enough entity data into a byte array to fill the array.
Parameters | |
---|---|
b |
byte :
Byte array to fill with data from the stream. If the stream does not
have sufficient data to fill the array, then the contents of the remainder of
the array will be undefined. |
Returns | |
---|---|
int |
The number of bytes of data read, or zero if all of the entity's data has already been read. |
Throws | |
---|---|
IOException |
int size ()
Report the total number of bytes of data available for the current entity.
Returns | |
---|---|
int |
The number of data bytes available, equivalent to calling
getDataSize() on the underlying BackupDataInput .
|