Top Description Fields Constructors Methods
sun.nio.ch

pack-priv Class ChannelInputStream

extends InputStream
Class Inheritance
Imports
java.io.InputStream, .IOException, .OutputStream, java.nio.ByteBuffer, java.nio.channels.FileChannel, .IllegalBlockingModeException, .ReadableByteChannel, .SeekableByteChannel, .SelectableChannel, .WritableByteChannel, java.util.Arrays, .Objects, jdk.internal.util.ArraysSupport

An InputStream that reads bytes from a channel.
Authors
Mike McCloskey, Mark Reinhold

Field Summary

Modifier and TypeField and Description
private byte[]
private ByteBuffer
private byte[]
private final ReadableByteChannel
private static final int

Constructor Summary

AccessConstructor and Description
pack-priv
ChannelInputStream(ReadableByteChannel ch)

Initialize a ChannelInputStream that reads from the given channel.

Method Summary

Modifier and TypeMethod and Description
public int
available()

Overrides java.io.InputStream.available.

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking, which may be 0, or 0 when end of stream is detected.

public void
close()

Overrides java.io.InputStream.close.

Implements java.io.Closeable.close.

Closes this input stream and releases any system resources associated with the stream.

private int
read(ByteBuffer bb)

Reads a sequence of bytes from the channel into the given buffer.

public synchronized int
read()

Implements abstract java.io.InputStream.read.

Reads the next byte of data from the input stream.

public synchronized int
read(byte[]
the buffer into which the data is read.
bs
,
int
the start offset in array b at which the data is written.
off
,
int
the maximum number of bytes to read.
len
)

Overrides java.io.InputStream.read.

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

public byte[]
readAllBytes()

Overrides java.io.InputStream.readAllBytes.

Reads all remaining bytes from the input stream.

public byte[]
readNBytes(int
the maximum number of bytes to read
len
)

Overrides java.io.InputStream.readNBytes.

Reads up to a specified number of bytes from the input stream.

public synchronized long
skip(long
the number of bytes to be skipped.
n
)

Overrides java.io.InputStream.skip.

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

private static long
transfer(FileChannel fc, WritableByteChannel target)

Transfers all bytes from a channel's file to a target writeable byte channel.

private static long
transfer(ReadableByteChannel src, FileChannel dst)

Transfers all bytes from a readable byte channel to a target channel's file.

public long
transferTo(OutputStream
the output stream, non-null
out
)

Overrides java.io.InputStream.transferTo.

Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read.

Inherited from java.io.InputStream:
markmarkSupportednullInputStreamreadreadNBytesresetskipNBytes

Field Detail

b1back to summary
private byte[] b1
bbback to summary
private ByteBuffer bb
bsback to summary
private byte[] bs
chback to summary
private final ReadableByteChannel ch
DEFAULT_BUFFER_SIZEback to summary
private static final int DEFAULT_BUFFER_SIZE

Hides java.io.InputStream.DEFAULT_BUFFER_SIZE.

Constructor Detail

ChannelInputStreamback to summary
pack-priv ChannelInputStream(ReadableByteChannel ch)

Initialize a ChannelInputStream that reads from the given channel.

Method Detail

availableback to summary
public int available() throws IOException

Overrides java.io.InputStream.available.

Doc from java.io.InputStream.available.

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking, which may be 0, or 0 when end of stream is detected. The read might be on 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.

Note that while some implementations of InputStream will return the total number of bytes in the stream, many will not. It is never correct to use the return value of this method to allocate a buffer intended to hold all data in this stream.

A subclass's implementation of this method may choose to throw an IOException if this input stream has been closed by invoking the close() method.

Returns:int

an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking or 0 when it reaches the end of the input stream.

Annotations
@Override
Exceptions
IOException:
if an I/O error occurs.
closeback to summary
public void close() throws IOException

Overrides java.io.InputStream.close.

Implements java.io.Closeable.close.

Doc from java.io.InputStream.close.

Closes this input stream and releases any system resources associated with the stream.

Annotations
@Override
Exceptions
IOException:
if an I/O error occurs.
readback to summary
private int read(ByteBuffer bb) throws IOException

Reads a sequence of bytes from the channel into the given buffer.

readback to summary
public synchronized int read() throws IOException

Implements abstract java.io.InputStream.read.

Doc from java.io.InputStream.read.

Reads the next byte of data from the input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Returns:int

the next byte of data, or -1 if the end of the stream is reached.

Annotations
@Override
Exceptions
IOException:
if an I/O error occurs.
readback to summary
public synchronized int read(byte[] bs, int off, int len) throws IOException

Overrides java.io.InputStream.read.

Doc from java.io.InputStream.read.

Reads up to len bytes of data from the input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read. The number of bytes actually read is returned as an integer.

This method blocks until input data is available, end of file is detected, or an exception is thrown.

If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

The first byte read is stored into element b[off], the next one into b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k] through b[off+len-1] unaffected.

In every case, elements b[0] through b[off-1] and elements b[off+len] through b[b.length-1] are unaffected.

Parameters
bs:byte[]

the buffer into which the data is read.

off:int

the start offset in array b at which the data is written.

len:int

the maximum number of bytes to 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 stream has been reached.

Annotations
@Override
Exceptions
IOException:
If the first byte cannot be read for any reason other than end of file, or if the input stream has been closed, or if some other I/O error occurs.
readAllBytesback to summary
public byte[] readAllBytes() throws IOException

Overrides java.io.InputStream.readAllBytes.

Doc from java.io.InputStream.readAllBytes.

Reads all remaining bytes from the input stream. This method blocks until all remaining bytes have been read and end of stream is detected, or an exception is thrown. This method does not close the input stream.

When this stream reaches end of stream, further invocations of this method will return an empty byte array.

Note that this method is intended for simple cases where it is convenient to read all bytes into a byte array. It is not intended for reading input streams with large amounts of data.

The behavior for the case where the input stream is asynchronously closed, or the thread interrupted during the read, is highly input stream specific, and therefore not specified.

If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes have been read. Consequently the input stream may not be at end of stream and may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.

Returns:byte[]

a byte array containing the bytes read from this input stream

Annotations
@Override
Exceptions
IOException:
if an I/O error occurs
readNBytesback to summary
public byte[] readNBytes(int len) throws IOException

Overrides java.io.InputStream.readNBytes.

Doc from java.io.InputStream.readNBytes.

Reads up to a specified number of bytes from the input stream. This method blocks until the requested number of bytes has been read, end of stream is detected, or an exception is thrown. This method does not close the input stream.

The length of the returned array equals the number of bytes read from the stream. If len is zero, then no bytes are read and an empty byte array is returned. Otherwise, up to len bytes are read from the stream. Fewer than len bytes may be read if end of stream is encountered.

When this stream reaches end of stream, further invocations of this method will return an empty byte array.

Note that this method is intended for simple cases where it is convenient to read the specified number of bytes into a byte array. The total amount of memory allocated by this method is proportional to the number of bytes read from the stream which is bounded by len. Therefore, the method may be safely called with very large values of len provided sufficient memory is available.

The behavior for the case where the input stream is asynchronously closed, or the thread interrupted during the read, is highly input stream specific, and therefore not specified.

If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes have been read. Consequently the input stream may not be at end of stream and may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.

Parameters
len:int

the maximum number of bytes to read

Returns:byte[]

a byte array containing the bytes read from this input stream

Annotations
@Override
Exceptions
IOException:
if an I/O error occurs
skipback to summary
public synchronized long skip(long n) throws IOException

Overrides java.io.InputStream.skip.

Doc from java.io.InputStream.skip.

Skips over and discards n bytes of data from this input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. The actual number of bytes skipped is returned. If n is negative, the skip method for class InputStream always returns 0, and no bytes are skipped. Subclasses may handle the negative value differently.

Parameters
n:long

the number of bytes to be skipped.

Returns:long

the actual number of bytes skipped which might be zero.

Annotations
@Override
Exceptions
IOException:
if an I/O error occurs.
transferback to summary
private static long transfer(FileChannel fc, WritableByteChannel target) throws IOException

Transfers all bytes from a channel's file to a target writeable byte channel. If the writeable byte channel is a selectable channel then it must be in blocking mode.

transferback to summary
private static long transfer(ReadableByteChannel src, FileChannel dst) throws IOException

Transfers all bytes from a readable byte channel to a target channel's file. If the readable byte channel is a selectable channel then it must be in blocking mode.

transferToback to summary
public long transferTo(OutputStream out) throws IOException

Overrides java.io.InputStream.transferTo.

Doc from java.io.InputStream.transferTo.

Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read. On return, this input stream will be at end of stream. This method does not close either stream.

This method may block indefinitely reading from the input stream, or writing to the output stream. The behavior for the case where the input and/or output stream is asynchronously closed, or the thread interrupted during the transfer, is highly input and output stream specific, and therefore not specified.

If the total number of bytes transferred is greater than Long#MAX_VALUE, then Long.MAX_VALUE will be returned.

If an I/O error occurs reading from the input stream or writing to the output stream, then it may do so after some bytes have been read or written. Consequently the input stream may not be at end of stream and one, or both, streams may be in an inconsistent state. It is strongly recommended that both streams be promptly closed if an I/O error occurs.

Parameters
out:OutputStream

the output stream, non-null

Returns:long

the number of bytes transferred

Annotations
@Override
Exceptions
IOException:
if an I/O error occurs when reading or writing