com.voytechs.jnetstream.io
Class ProtocolDataInputStream

java.lang.Object
  java.io.InputStream
      com.voytechs.jnetstream.io.ProtocolDataInputStream

All Implemented Interfaces:

java.io.Closeable

Direct Known Subclasses:

PacketInputStream

public abstract class ProtocolDataInputStream
extends java.io.InputStream

This stream object extends the DataInputStream which defines how to read basic data types from a binary stream. This stream in addition to the Java native primitives that DataInput defines, add ability to read on a variable bit boundry. Any subset of bits can be read and returned in 'int' data type.

Field Summary

protected int	bitsLeft This is the bit offset wihin the bytes that we have read so far.
protected java.io.DataInputStream	in Our source DataInputStream since we require to provide similar interface as it is.

Constructor Summary

ProtocolDataInputStream(java.io.DataInputStream inputStream)
Initialize with DataInputStream.

ProtocolDataInputStream(java.io.InputStream inputStream)

Method Summary

protected abstract boolean	isReady()
protected abstract boolean	isReady(int len)
static void	main(java.lang.String[] args) Test function for ProtocolDataInputStream
int	read() Any normal read() operation invalidates our bit cache since we only allow reads to happen at the byte boudary.
int	readBits(int numOfBits) Read from the stream number of bits and return them as a 'int' data type while advancing the bit-based position in the stream.
long	readBitsLong(int numOfBits) Read from the stream number of bits and return them as a 'long' data type while advancing the bit-based position in the stream.
boolean	readBoolean() Read one input byte and returns true if that byte is nonzero, false if that bye is zero.
byte	readByte() Read one byte from the stream.
java.math.BigInteger	readerUnsignedLongLittleEndian()
int	readFromPacket() Reads a 1 byte from stream but returns it as an int.
int	readFromPacket(byte[] array) Reads n bytes from stream but returns it as an int.
int	readInt() Reads a 32bit int using Big Endian encoding from stream.
int	readIntLittleEndian() Reads a 32bit int using Little Endian encoding from stream.
long	readLong() Reads a 64bit unsigned int using Big Endian encoding from stream.
long	readLongLittleEndian() Reads a 64bit long int using Little Endian encoding from stream.
int	readShort() Reads a 32bit int using Big Endian encoding from stream.
short	readShortLittleEndian() Reads a 16bit short using Little Endian encoding from stream.
int	readUnsignedByte() Reads a 1 byte from stream but returns it as an int.
long	readUnsignedInt() Reads a 32bit unsigned int using Big Endian encoding from stream.
long	readUnsignedIntLittleEndian() Reads a 32bit int using Little Endian encoding from stream.
java.math.BigInteger	readUnsignedLong()
int	readUnsignedShort() Reads a 16bit unsigned int using Big Endian encoding from stream.
int	readUnsignedShortLittleEndian() Reads a 16bit unsigned short using Little Endian encoding from stream.
protected void	reThrow(java.io.IOException ioe) Conveniece method that checks if the stream has thrown EOFException.

Methods inherited from class java.io.InputStream

available, close, mark, markSupported, read, read, reset, skip

Methods inherited from class java.lang.Object

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

Field Detail

bitsLeft

protected int bitsLeft

This is the bit offset wihin the bytes that we have read so far. If bitsLeft == 0 then there is no real data in the chachedByte variable if bitsLeft > 1 and bitOffset < 7 then we have real data in the cached byte and should read from upto the remainder of the cache. It should always have values between 0 and 7;

in

protected java.io.DataInputStream in

Our source DataInputStream since we require to provide similar interface as it is.

Constructor Detail

ProtocolDataInputStream

public ProtocolDataInputStream(java.io.DataInputStream inputStream)

Initialize with DataInputStream. We will besides the baseclasses functions to read native data types from the stream we will define methods for accessing on variouable bit boundries.

Parameters:

inputStream - Stream to read underlying data from.

ProtocolDataInputStream

public ProtocolDataInputStream(java.io.InputStream inputStream)

Method Detail

read

public int read()
         throws java.io.IOException

Any normal read() operation invalidates our bit cache since we only allow reads to happen at the byte boudary.

Specified by:

read in class java.io.InputStream

Returns:

reads the next byte of the stream and returns it as an int. Invalidates any bit positioning within the stream and aligns the next bit read at the start of the next byte.

Throws:

java.io.IOException - any exceptions thrown by source input stream

readBits

public int readBits(int numOfBits)
             throws java.io.IOException

Read from the stream number of bits and return them as a 'int' data type while advancing the bit-based position in the stream.

Parameters:

numOfBits - Number of bits (0 to 32) to read from the stream starting at the current byte and bit position. The maximum number of bits that can be read is 32. 0 count of bits will always return value 0 and will not advance the position in the stream. Less then 0 will generate an IvalidArgumentException.

Throws:

InvalidArgumentExcpeption - is trown if numOfBits is outside the 0 to 32 range.

java.io.IOException - any IOException thrown by source input stream.

readBitsLong

public long readBitsLong(int numOfBits)
                  throws java.io.IOException

Read from the stream number of bits and return them as a 'long' data type while advancing the bit-based position in the stream.

Parameters:

numOfBits - Number of bits (0 to 64) to read from the stream starting at the current byte and bit position. The maximum number of bits that can be read is 64. 0 count of bits will always return value 0 and will not advance the position in the stream. Less then 0 will generate an IvalidArgumentException.

Throws:

InvalidArgumentExcpeption - is trown if numOfBits is outside the 0 to 64 range.

java.io.IOException - any IOException thrown by source input stream.

isReady

protected abstract boolean isReady(int len)
                            throws EOPacket

Throws:

EOPacket

isReady

protected abstract boolean isReady()
                            throws EOPacket

Throws:

EOPacket

readByte

public byte readByte()
              throws java.io.IOException,
                     EOPacket,
                     EOPacketStream

Read one byte from the stream.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readBoolean

public boolean readBoolean()
                    throws java.io.IOException,
                           EOPacket,
                           EOPacketStream

Read one input byte and returns true if that byte is nonzero, false if that bye is zero.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readInt

public int readInt()
            throws java.io.IOException,
                   EOPacket,
                   EOPacketStream

Reads a 32bit int using Big Endian encoding from stream.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readShort

public int readShort()
              throws java.io.IOException,
                     EOPacket,
                     EOPacketStream

Reads a 32bit int using Big Endian encoding from stream.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readUnsignedInt

public long readUnsignedInt()
                     throws java.io.IOException,
                            EOPacket,
                            EOPacketStream

Reads a 32bit unsigned int using Big Endian encoding from stream.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readUnsignedShort

public int readUnsignedShort()
                      throws java.io.IOException,
                             EOPacket,
                             EOPacketStream

Reads a 16bit unsigned int using Big Endian encoding from stream.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readLong

public long readLong()
              throws java.io.IOException,
                     EOPacket,
                     EOPacketStream

Reads a 64bit unsigned int using Big Endian encoding from stream.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readShortLittleEndian

public short readShortLittleEndian()
                            throws java.io.IOException,
                                   EOPacket,
                                   EOPacketStream

Reads a 16bit short using Little Endian encoding from stream.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readIntLittleEndian

public int readIntLittleEndian()
                        throws java.io.IOException,
                               EOPacket,
                               EOPacketStream

Reads a 32bit int using Little Endian encoding from stream.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readUnsignedIntLittleEndian

public long readUnsignedIntLittleEndian()
                                 throws java.io.IOException,
                                        EOPacket,
                                        EOPacketStream

Reads a 32bit int using Little Endian encoding from stream.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readLongLittleEndian

public long readLongLittleEndian()
                          throws java.io.IOException,
                                 EOPacket,
                                 EOPacketStream

Reads a 64bit long int using Little Endian encoding from stream.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readUnsignedShortLittleEndian

public int readUnsignedShortLittleEndian()
                                  throws java.io.IOException,
                                         EOPacket,
                                         EOPacketStream

Reads a 16bit unsigned short using Little Endian encoding from stream.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readUnsignedLong

public java.math.BigInteger readUnsignedLong()
                                      throws java.io.IOException,
                                             EOPacket,
                                             EOPacketStream

Throws:

java.io.IOException

EOPacket

EOPacketStream

readerUnsignedLongLittleEndian

public java.math.BigInteger readerUnsignedLongLittleEndian()
                                                    throws java.io.IOException,
                                                           EOPacket,
                                                           EOPacketStream

Throws:

java.io.IOException

EOPacket

EOPacketStream

readFromPacket

public int readFromPacket()
                   throws java.io.IOException,
                          EOPacket,
                          EOPacketStream

Reads a 1 byte from stream but returns it as an int. This is replaces the normal read() method but implements ProtocolStream specific exception reporting.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readFromPacket

public int readFromPacket(byte[] array)
                   throws java.io.IOException,
                          EOPacket,
                          EOPacketStream

Reads n bytes from stream but returns it as an int. This is replaces the normal read() method but implements ProtocolStream specific exception reporting.

Throws:

java.io.IOException

EOPacket

EOPacketStream

readUnsignedByte

public int readUnsignedByte()
                     throws java.io.IOException,
                            EOPacket,
                            EOPacketStream

Reads a 1 byte from stream but returns it as an int. This is replaces the normal read() method but implements ProtocolStream specific exception reporting.

Throws:

java.io.IOException

EOPacket

EOPacketStream

reThrow

protected void reThrow(java.io.IOException ioe)
                throws java.io.IOException,
                       EOPacketStream

Conveniece method that checks if the stream has thrown EOFException. If yes then EOPacketStream exception is thrown instead otherwise the original exception is re-thrown.

This method always throws an exception. Either original or new EOPacketStream.

Parameters:

ioe - IOException to check if its EOFException.

Throws:

java.io.IOException - original exception re-thrown again.

EOPacketStream - a replacement exception is thrown which indicates that end of packet stream has been reached.

main

public static void main(java.lang.String[] args)

Test function for ProtocolDataInputStream

Parameters:

args - command line arguments