org.ka2ddo.yaac.io

Class JsscInputStream

java.lang.Object

java.io.InputStream

org.ka2ddo.yaac.io.JsscInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class JsscInputStream
extends java.io.InputStream

This class provides an InputStream-like interface to a jssc.SerialPort object. Note that closing a JsscInputStream does nothing, as there is no way to close half of a SerialPort. The SerialPort.closePort() method must be called to actually release access to the serial device file.

Author:

Andrew Pavlin, KA2DDO

Constructor Summary

Constructors

Constructor and Description
JsscInputStream(jssc.SerialPort serialPort) Wrap an InputStream around a jssc.SerialPort.

Method Summary

Modifier and Type	Method and Description
int	available() Returns an estimate of the number of 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.
int	read() Reads the next byte of data from the input stream.
int	read(byte[] b) Reads some number of bytes from the input stream and stores them into the buffer array b.
int	read(byte[] b, int off, int len) Reads up to len bytes of data from the input stream into an array of bytes.

Methods inherited from class java.io.InputStream

close, mark, markSupported, reset, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

JsscInputStream

public JsscInputStream(jssc.SerialPort serialPort)

Wrap an InputStream around a jssc.SerialPort.

Parameters:

serialPort - SerialPort object to read from

Method Detail

read

public int read()
         throws java.io.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 java.io.InputStream

Returns:

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

Throws:

java.io.IOException - if an I/O error occurs.

read

public int read(byte[] b)
         throws java.io.IOException

Reads some number of bytes from the input stream and stores them into the buffer array b. 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 the length of b 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 the end of the 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[0], the next one into b[1], and so on. The number of bytes read is, at most, equal to the length of b. Let k be the number of bytes actually read; these bytes will be stored in elements b[0] through b[k-1], leaving elements b[k] through b[b.length-1] unaffected.

Overrides:

read in class java.io.InputStream

Parameters:

b - the buffer into which the data is read.

Returns:

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.

Throws:

java.io.IOException - If the first byte cannot be read for any reason other than the end of the file, if the input stream has been closed, or if some other I/O error occurs.

java.lang.NullPointerException - if b is null.

See Also:

InputStream.read(byte[], int, int)

read

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

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] and elements b[off+len] through b[b.length-1] are unaffected.

Overrides:

read in class java.io.InputStream

Parameters:

b - the buffer into which the data is read.

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

len - the maximum number of bytes to read.

Returns:

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.

Throws:

java.io.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.

java.lang.NullPointerException - If b is null.

java.lang.IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than b.length - off

See Also:

InputStream.read()

available

public int available()
              throws java.io.IOException

Returns an estimate of the number of 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. 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.

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

The available method for class InputStream always returns 0.

Overrides:

available in class java.io.InputStream

Returns:

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.

Throws:

java.io.IOException - if an I/O error occurs.