public interface DataSource
Modifier and Type | Interface and Description |
---|---|
static interface |
DataSource.Factory
A factory for
DataSource instances. |
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 . |
long open(DataSpec dataSpec) throws IOException
Note: If an IOException
is thrown, callers must still call close()
to ensure
that any partial effects of the invocation are cleaned up.
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
.IOException
- If an error occurs opening the source. DataSourceException
can be
thrown or used as a cause of the thrown exception to specify the reason of the error.int read(byte[] buffer, int offset, int readLength) throws IOException
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.
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.IOException
- If an error occurs reading from the source.Uri getUri()
Uri
from which data is being read. The returned
Uri
will be identical to the one passed open(DataSpec)
in the DataSpec
unless redirection has occurred. If redirection has occurred, the Uri
after redirection
is returned.Uri
from which data is being read, or null if the source is not open.void close() throws IOException
Note: This method must be called even if the corresponding call to open(DataSpec)
threw an IOException
. See open(DataSpec)
for more details.
IOException
- If an error occurs closing the source.