Added in API level 3

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 FileChannel object associated with this file input stream.

void mark(int readlimit)

Marks the current position in this input stream.

boolean markSupported()

Tests if this input stream supports the mark and reset methods.

int read()

Reads a byte of data from this input stream.

int read(byte[] buffer, int offset, int count)

Reads up to len bytes of data from this input stream into an array of bytes.

int read(byte[] buffer)

Reads up to b.length bytes of data from this input stream into an array of bytes.

void reset()

Repositions this stream to the position at the time the mark method was last called on this input stream.

long skip(long count)

Skips over and discards n bytes of data from the input stream.

Inherited methods

Public constructors

AutoCloseInputStream

Added in API level 3
public AutoCloseInputStream (AssetFileDescriptor fd)

Parameters
fd AssetFileDescriptor

Throws
IOException

Public methods

available

Added in API level 3
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

Added in API level 3
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

Added in API level 3
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

Added in API level 3
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

Added in API level 3
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

Added in API level 3
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

Added in API level 3
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

Added in API level 3
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

Added in API level 3
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 returns true, then:
    • If the method mark has not been called since the stream was created, or the number of bytes read from the stream since mark was last called is larger than the argument to mark at that last call, then an IOException 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 to mark (or since the start of the file, if mark has not been called) will be resupplied to subsequent callers of the read method, followed by any bytes that otherwise would have been the next input data as of the time of the call to reset.
  • If the method markSupported returns false, then:
    • The call to reset may throw an IOException.
    • 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 the read method depend on the particular type of the input stream.

The method reset for class InputStream does nothing except throw an IOException.

Throws
IOException

skip

Added in API level 3
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