Package org.jline.utils

Class NonBlockingInputStream

java.lang.Object

java.io.InputStream

org.jline.utils.NonBlockingInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

NonBlockingInputStreamImpl, NonBlockingPumpInputStream

public abstract class NonBlockingInputStream
extends InputStream

An input stream that supports non-blocking read operations with timeouts.

The NonBlockingInputStream class extends InputStream to provide non-blocking read operations. Unlike standard input streams, which block indefinitely until data is available or the end of the stream is reached, non-blocking input streams can be configured to return immediately or after a specified timeout if no data is available.

This class defines two special return values:

• EOF (-1) - Indicates that the end of the stream has been reached
• READ_EXPIRED (-2) - Indicates that the read operation timed out

This abstract class provides the framework for non-blocking input operations, with concrete implementations handling the details of how the non-blocking behavior is achieved (e.g., through NIO, separate threads, or native methods).

Non-blocking input streams are particularly useful for terminal applications that need to perform other tasks while waiting for user input, or that need to implement features like input timeouts or polling.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	EOF
static final int	READ_EXPIRED

Constructor Summary

Constructors

Constructor	Description
NonBlockingInputStream()

Method Summary

Modifier and Type	Method	Description
int	peek(long timeout)	Peeks to see if there is a byte waiting in the input stream without actually consuming the byte.
int	read()	Reads the next byte of data from the input stream.
int	read(byte[] b, int off, int len)
int	read(long timeout)	Attempts to read a character from the input stream for a specific period of time.
abstract int	read(long timeout, boolean isPeek)
int	readBuffered(byte[] b)
int	readBuffered(byte[] b, int off, int len, long timeout)
int	readBuffered(byte[] b, long timeout)
void	shutdown()	Shuts down the thread that is handling blocking I/O if any.

Methods inherited from class java.io.InputStream

available, close, mark, markSupported, nullInputStream, read, readAllBytes, readNBytes, readNBytes, reset, skip, skipNBytes, transferTo

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

EOF

public static final int EOF

See Also:

• Constant Field Values

READ_EXPIRED

public static final int READ_EXPIRED

See Also:

• Constant Field Values

Constructor Details

NonBlockingInputStream

public NonBlockingInputStream()

Method Details

read

public int read()
         throws IOException

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.

Specified by:

read in class InputStream

Returns:

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

Throws:

IOException - if an I/O error occurs.

peek

public int peek(long timeout)
         throws IOException

Peeks to see if there is a byte waiting in the input stream without actually consuming the byte.

Parameters:

timeout - The amount of time to wait, 0 == forever

Returns:

-1 on eof, -2 if the timeout expired with no available input or the character that was read (without consuming it).

Throws:

IOException - if an I/O error occurs.

read

public int read(long timeout)
         throws IOException

Attempts to read a character from the input stream for a specific period of time.

Parameters:

timeout - The amount of time to wait for the character

Returns:

The character read, -1 if EOF is reached, or -2 if the read timed out.

Throws:

IOException - if an I/O error occurs.

read

public int read(byte[] b,
 int off,
 int len)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

readBuffered

public int readBuffered(byte[] b)
                 throws IOException

Throws:

IOException

readBuffered

public int readBuffered(byte[] b,
 long timeout)
                 throws IOException

Throws:

IOException

readBuffered

public int readBuffered(byte[] b,
 int off,
 int len,
 long timeout)
                 throws IOException

Throws:

IOException

shutdown

public void shutdown()

Shuts down the thread that is handling blocking I/O if any. Note that if the thread is currently blocked waiting for I/O it may not actually shut down until the I/O is received.

read

public abstract int read(long timeout,
 boolean isPeek)
                  throws IOException

Throws:

IOException