AssetFileDescriptor.AutoCloseInputStream
public
static
class
AssetFileDescriptor.AutoCloseInputStream
extends ParcelFileDescriptor.AutoCloseInputStream
java.lang.Object | ||||
↳ | java.io.InputStream | |||
↳ | java.io.FileInputStream | |||
↳ | android.os.ParcelFileDescriptor.AutoCloseInputStream | |||
↳ | android.content.res.AssetFileDescriptor.AutoCloseInputStream |
An InputStream you can create on a ParcelFileDescriptor, which will
take care of calling ParcelFileDescriptor.close()
for you when the stream is closed.
It has a ParcelFileDescriptor.AutoCloseInputStream member to make delegate calls
and during definition it will create seekable or non seekable child object
AssetFileDescriptor.AutoCloseInputStream depends on the type of file descriptor
to provide different solution.
Summary
Public constructors | |
---|---|
AutoCloseInputStream(AssetFileDescriptor fd)
|
Public methods | |
---|---|
int
|
available()
Returns an estimate of the number of remaining bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. |
void
|
close()
Closes this file input stream and releases any system resources associated with the stream. |
FileChannel
|
getChannel()
Returns the unique |
void
|
mark(int readlimit)
Marks the current position in this input stream. |
boolean
|
markSupported()
Tests if this input stream supports the |
int
|
read()
Reads a byte of data from this input stream. |
int
|
read(byte[] buffer, int offset, int count)
Reads up to |
int
|
read(byte[] buffer)
Reads up to |
void
|
reset()
Repositions this stream to the position at the time the
|
long
|
skip(long count)
Skips over and discards |
Inherited methods | |
---|---|
Public constructors
AutoCloseInputStream
public AutoCloseInputStream (AssetFileDescriptor fd)
Parameters | |
---|---|
fd |
AssetFileDescriptor |
Throws | |
---|---|
IOException |
Public methods
available
public int available ()
Returns an estimate of the number of remaining bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. Returns 0 when the file position is beyond EOF. The next invocation might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.
In some cases, a non-blocking read (or skip) may appear to be blocked when it is merely slow, for example when reading large files over slow networks.
Returns | |
---|---|
int |
an estimate of the number of remaining bytes that can be read (or skipped over) from this input stream without blocking. |
Throws | |
---|---|
IOException |
close
public void close ()
Closes this file input stream and releases any system resources associated with the stream.
If this stream has an associated channel then the channel is closed as well.
Throws | |
---|---|
IOException |
getChannel
public FileChannel getChannel ()
Returns the unique FileChannel
object associated with this file input stream.
The initial position
of the returned channel will be equal to the
number of bytes read from the file so far. Reading bytes from this
stream will increment the channel's position. Changing the channel's
position, either explicitly or by reading, will change this stream's
file position.
Returns | |
---|---|
FileChannel |
the file channel associated with this file input stream |
mark
public void mark (int readlimit)
Marks the current position in this input stream. A subsequent call to
the reset
method repositions this stream at the last marked
position so that subsequent reads re-read the same bytes.
The readlimit
arguments tells this input stream to
allow that many bytes to be read before the mark position gets
invalidated.
The general contract of mark
is that, if the method
markSupported
returns true
, the stream somehow
remembers all the bytes read after the call to mark
and
stands ready to supply those same bytes again if and whenever the method
reset
is called. However, the stream is not required to
remember any data at all if more than readlimit
bytes are
read from the stream before reset
is called.
Marking a closed stream should not have any effect on the stream.
The mark
method of InputStream
does
nothing.
Parameters | |
---|---|
readlimit |
int : the maximum limit of bytes that can be read before
the mark position becomes invalid. |
markSupported
public boolean markSupported ()
Tests if this input stream supports the mark
and
reset
methods. Whether or not mark
and
reset
are supported is an invariant property of a
particular input stream instance. The markSupported
method
of InputStream
returns false
.
Returns | |
---|---|
boolean |
true if this stream instance supports the mark
and reset methods; false otherwise. |
read
public int read ()
Reads a byte of data from this input stream. This method blocks if no input is yet available.
Returns | |
---|---|
int |
the next byte of data, or -1 if the end of the
file is reached. |
Throws | |
---|---|
IOException |
read
public int read (byte[] buffer, int offset, int count)
Reads up to len
bytes of data from this input stream
into an array of bytes. If len
is not zero, the method
blocks until some input is available; otherwise, no
bytes are read and 0
is returned.
Parameters | |
---|---|
buffer |
byte : the buffer into which the data is read. |
offset |
int : the start offset in the destination array b |
count |
int : the maximum number of bytes read. |
Returns | |
---|---|
int |
the total number of bytes read into the buffer, or
-1 if there is no more data because the end of
the file has been reached. |
Throws | |
---|---|
IOException |
read
public int read (byte[] buffer)
Reads up to b.length
bytes of data from this input
stream into an array of bytes. This method blocks until some input
is available.
Parameters | |
---|---|
buffer |
byte : the buffer into which the data is read. |
Returns | |
---|---|
int |
the total number of bytes read into the buffer, or
-1 if there is no more data because the end of
the file has been reached. |
Throws | |
---|---|
IOException |
reset
public void reset ()
Repositions this stream to the position at the time the
mark
method was last called on this input stream.
The general contract of reset
is:
- If the method
markSupported
returnstrue
, then:- If the method
mark
has not been called since the stream was created, or the number of bytes read from the stream sincemark
was last called is larger than the argument tomark
at that last call, then anIOException
might be thrown. - If such an
IOException
is not thrown, then the stream is reset to a state such that all the bytes read since the most recent call tomark
(or since the start of the file, ifmark
has not been called) will be resupplied to subsequent callers of theread
method, followed by any bytes that otherwise would have been the next input data as of the time of the call toreset
.
- If the method
- If the method
markSupported
returnsfalse
, then:- The call to
reset
may throw anIOException
. - If an
IOException
is not thrown, then the stream is reset to a fixed state that depends on the particular type of the input stream and how it was created. The bytes that will be supplied to subsequent callers of theread
method depend on the particular type of the input stream.
- The call to
The method reset
for class InputStream
does nothing except throw an IOException
.
Throws | |
---|---|
IOException |
skip
public long skip (long count)
Skips over and discards n
bytes of data from the
input stream.
The skip
method may, for a variety of
reasons, end up skipping over some smaller number of bytes,
possibly 0
. If n
is negative, the method
will try to skip backwards. In case the backing file does not support
backward skip at its current position, an IOException
is
thrown. The actual number of bytes skipped is returned. If it skips
forwards, it returns a positive value. If it skips backwards, it
returns a negative value.
This method may skip more bytes than what are remaining in the backing file. This produces no exception and the number of bytes skipped may include some number of bytes that were beyond the EOF of the backing file. Attempting to read from the stream after skipping past the end will result in -1 indicating the end of the file.
Parameters | |
---|---|
count |
long : the number of bytes to be skipped. |
Returns | |
---|---|
long |
the actual number of bytes skipped. |
Throws | |
---|---|
IOException |