Top Description Fields Constructors Methods
org.apache.sshd.common.util.io.input

public Class CloseableEmptyInputStream

extends EmptyInputStream
implements Channel
Class Inheritance
All Implemented Interfaces
java.nio.channels.Channel, java.io.Closeable, java.lang.AutoCloseable
Imports
java.io.IOException, java.nio.channels.Channel, java.util.concurrent.atomic.AtomicBoolean

A /dev/null stream that can be closed - in which case it will throw IOExceptions if invoked after being closed
Author
Apache MINA SSHD Project

Field Summary

Modifier and TypeField and Description
private final AtomicBoolean
Inherited from org.apache.sshd.common.util.io.input.EmptyInputStream:
DEV_NULL

Constructor Summary

AccessConstructor and Description
public

Method Summary

Modifier and TypeMethod and Description
public int
available()

Overrides org.apache.sshd.common.util.io.input.EmptyInputStream.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
public boolean
isOpen()

Implements java.nio.channels.Channel.isOpen.

Tells whether or not this channel is open.

public int
read()

Overrides org.apache.sshd.common.util.io.input.EmptyInputStream.read.

Reads the next byte of data from the input stream.

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

Overrides org.apache.sshd.common.util.io.input.EmptyInputStream.read.

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

public synchronized void
reset()

Overrides org.apache.sshd.common.util.io.input.EmptyInputStream.reset.

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

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

Overrides org.apache.sshd.common.util.io.input.EmptyInputStream.skip.

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

Inherited from org.apache.sshd.common.util.io.input.EmptyInputStream:
mark

Field Detail

openback to summary
private final AtomicBoolean open

Constructor Detail

CloseableEmptyInputStreamback to summary
public CloseableEmptyInputStream()

Method Detail

availableback to summary
public int available() throws IOException

Overrides org.apache.sshd.common.util.io.input.EmptyInputStream.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.nio.channels.Channel.close, java.io.Closeable.close.

Doc from java.nio.channels.Channel.close.

Closes this channel.

After a channel is closed, any further attempt to invoke I/O operations upon it will cause a ClosedChannelException to be thrown.

If this channel is already closed then invoking this method has no effect.

This method may be invoked at any time. If some other thread has already invoked it, however, then another invocation will block until the first invocation is complete, after which it will return without effect.

Annotations
@Override
Exceptions
IOException:
If an I/O error occurs
isOpenback to summary
public boolean isOpen()

Implements java.nio.channels.Channel.isOpen.

Doc from java.nio.channels.Channel.isOpen.

Tells whether or not this channel is open.

Returns:boolean

true if, and only if, this channel is open

Annotations
@Override
readback to summary
public int read() throws IOException

Overrides org.apache.sshd.common.util.io.input.EmptyInputStream.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 int read(byte[] b, int off, int len) throws IOException

Overrides org.apache.sshd.common.util.io.input.EmptyInputStream.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
b: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.
resetback to summary
public synchronized void reset() throws IOException

Overrides org.apache.sshd.common.util.io.input.EmptyInputStream.reset.

Doc from java.io.InputStream.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.
Annotations
@Override
Exceptions
IOException:
if this stream has not been marked or if the mark has been invalidated.
skipback to summary
public long skip(long n) throws IOException

Overrides org.apache.sshd.common.util.io.input.EmptyInputStream.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.