public final class AssetDataSource extends Object implements DataSource
DataSource
for reading from a local asset.Modifier and Type | Class and Description |
---|---|
static class |
AssetDataSource.AssetDataSourceException
Thrown when an
IOException is encountered reading a local asset. |
DataSource.Factory
Constructor and Description |
---|
AssetDataSource(Context context) |
AssetDataSource(Context context,
TransferListener<? super AssetDataSource> listener) |
Modifier and Type | Method and Description |
---|---|
void |
close()
Closes the source.
|
Uri |
getUri()
When the source is open, returns the
Uri from which data is being read. |
long |
open(DataSpec dataSpec)
Opens the source to read the specified data.
|
int |
read(byte[] buffer,
int offset,
int readLength)
Reads up to
length bytes of data and stores them into buffer , starting at
index offset . |
public AssetDataSource(Context context)
context
- A context.public AssetDataSource(Context context, TransferListener<? super AssetDataSource> listener)
context
- A context.listener
- An optional listener.public long open(DataSpec dataSpec) throws AssetDataSource.AssetDataSourceException
DataSource
Note: If an IOException
is thrown, callers must still call DataSource.close()
to ensure
that any partial effects of the invocation are cleaned up.
open
in interface DataSource
dataSpec
- Defines the data to be read.DataSpec.length
equals C.LENGTH_UNSET
) this value
is the resolved length of the request, or C.LENGTH_UNSET
if the length is still
unresolved. For all other requests, the value returned will be equal to the request's
DataSpec.length
.AssetDataSource.AssetDataSourceException
public int read(byte[] buffer, int offset, int readLength) throws AssetDataSource.AssetDataSourceException
DataSource
length
bytes of data and stores them into buffer
, starting at
index offset
.
If length
is zero then 0 is returned. Otherwise, if no data is available because the
end of the opened range has been reached, then C.RESULT_END_OF_INPUT
is returned.
Otherwise, the call will block until at least one byte of data has been read and the number of
bytes read is returned.
read
in interface DataSource
buffer
- The buffer into which the read data should be stored.offset
- The start offset into buffer
at which data should be written.readLength
- The maximum number of bytes to read.C.RESULT_END_OF_INPUT
if no data is avaliable
because the end of the opened range has been reached.AssetDataSource.AssetDataSourceException
public Uri getUri()
DataSource
Uri
from which data is being read. The returned
Uri
will be identical to the one passed DataSource.open(DataSpec)
in the DataSpec
unless redirection has occurred. If redirection has occurred, the Uri
after redirection
is returned.getUri
in interface DataSource
Uri
from which data is being read, or null if the source is not open.public void close() throws AssetDataSource.AssetDataSourceException
DataSource
Note: This method must be called even if the corresponding call to DataSource.open(DataSpec)
threw an IOException
. See DataSource.open(DataSpec)
for more details.
close
in interface DataSource
AssetDataSource.AssetDataSourceException