Apache Derby Network Server 10.17.1.0 · org.apache.derby.impl.drda.DDMReader

Modifier and Type	Field and Description
private static final boolean	ADJUST_LENGTHS
private DRDAConnThread	agent
private byte[]	buffer
private CcsidManager	ccsidManager
private int	count
private long[]	ddmCollectionLenStack
private long	ddmScalarLen
private static final int	DEFAULT_BUFFER_SIZE
private boolean	doingLayerBStreaming
private int	dssCorrelationID
private boolean	dssIsChainedWithDiffID
private boolean	dssIsChainedWithSameID
private boolean	dssIsContinued
private int	dssLength
private DssTrace	dssTrace
private EbcdicCcsidManager	ebcdicCcsidManager
private static final int	EMPTY_STACK
private InputStream	inputStream
private static final long	MAX_EXTDTA_SIZE
private static final int	MAX_MARKS_NESTING
private static final boolean	NO_ADJUST_LENGTHS
private static final int	NO_CODEPOINT
private int	pos
private int	prevCorrelationID
private int	svrcod
private static final int[][]	tenRadixMagnitude
private boolean	terminateChainOnErr
private int	topDdmCollectionStack
pack-priv volatile long	totalByteCount
private Utf8CcsidManager	utf8CcsidManager

Access	Constructor and Description
pack-priv	DDMReader(DRDAConnThread agent, DssTrace dssTrace)
pack-priv	DDMReader(InputStream inputStream) This constructor is used for testing the protocol It is used by ProtocolTestAdapter to read the protocol returned by the server

Method Summary

Modifier and Type	Method and Description
private void	adjustLengths(int - adjustment length length) Adjust remaining length
protected void	clearBuffer()
private void	compressBLayerData(int - amount of data we need continueDssHeaderCount) Compress B Layer data if extended total length is used by removing the continuation headers
private int[]	Returns: array of int magnitudes computeMagnitude(int[] value segments input) Compute the int array of magnitude from input value segments.
protected String	Returns: string convertBytes(byte[] - byte array buf) Convert EBCDIC byte array to unicode string
pack-priv boolean	doingLayerBStreaming()
private void	ensureALayerDataInBuffer(int - amount of data we need desiredDataSize) Make sure a certain amount of Layer A data is in the buffer.
private void	ensureBLayerDataInBuffer(int - amount of data we need desiredDataSize, boolean - whether to adjust the remaining lengths adjustLen) Make sure a certain amount of Layer B data is in the buffer.
private void	ensureSpaceInBufferForFill(int - amount of data we need desiredSpace) This method makes sure there is enough room in the buffer for a certain number of bytes.
private void	fill(int - minimum required bytes minimumBytesNeeded) This method will attempt to read a minimum number of bytes from the underlying stream.
private void	finishLayerBStreaming()
protected int	Returns: NO_CODEPOINT if collection stack is empty or remaining length is 0; otherwise, read length and code point getCodePoint() Get the next CodePoint from a collection
protected int	Returns: codePoint getCodePoint(int - codePoint to check against codePointCheck) Get the next CodePoint from a collection and check that it matches the specified CodePoint
protected byte	getCurrChainState() Return chaining bit for current DSS.
protected long	Returns: length of DDM object getDdmLength() Length of current DDM object
pack-priv byte[]	getExtData(long desiredLength, boolean checkNullability)
pack-priv EXTDTAReaderInputStream	Returns: EXTDTAReaderInputStream object which can be passed to prepared statement as a binary stream. getEXTDTAReaderInputStream(final boolean used to check if the stream is null. If it is null, this method returns null checkNullability) Creates an InputStream which can stream EXTDTA objects.
protected void	initialize(DRDAConnThread agent, DssTrace dssTrace) Initialize values for this session, the reader is reused so we need to set null and 0 values
protected boolean	Returns: true if next DSS has a different correlator than current DSS isChainedWithDiffID() Next DSS has different correlator than current DSS
protected boolean	Returns: true if next DSS has the same correlator as current DSS isChainedWithSameID() Next DSS has same correlator as current DSS
protected boolean	Returns: true if this is a command; false otherwise isCmd() Check for the command protocol
private boolean	isEXTDTANull()
protected void	markCollection() Push DDM Length on to collection stack
protected boolean	Returns: true if there is more data in the buffer moreData() Is there more data in the buffer
protected boolean	Returns: true if DDM length is > 0 moreDdmData() Is there more in this DDM object
protected boolean	Returns: true if DDS length is > 0 moreDssData() Is there more in this DDS object
private int	Returns: an int value packedNybblesToInt(byte[] buffer to read from buffer, int offset in the buffer offset, int start nybble startNybble, int number of nybbles numberOfNybbles) Convert a range of packed nybbles (up to 9 digits without overflow) to an int.
private long	Returns: an long value packedNybblesToLong(byte[] buffer to read from buffer, int offset in the buffer offset, int start nybble startNybble, int number of nybbles numberOfNybbles) Convert a range of packed nybbles (up to 18 digits without overflow) to a long.
protected BigDecimal	Returns: value readBigDecimal(int of the BigDecimal precision, int of the BigDecimal scale) Read a BigDecimal value
protected byte	Returns: value readByte() Read byte value
protected byte[]	Returns: byte array readBytes(int - length of string to read length) Read byte string value
protected byte[]	Returns: byte array readBytes() Read byte string value
protected String	Returns: value readCmdString(int - length of string to read length) Read string value
protected String	Returns: value readCmdString() Read string value
protected int	Returns: - returns codepoint readCodePoint() Read the CodePoint
protected double	Returns: value readDouble(int byteOrder) Read platform double value
private void	readDSSContinuationHeader()
protected int	readDssHeader() Read DSS header DSS Header format is 2 bytes - length 1 byte - 'D0' - indicates DDM data 1 byte - DSS format \|---\|---------\|----------\| \| 0 \| flags \| type \| \|---\|---------\|----------\| \| 0 \| 1 2 3 \| 4 5 6 7 \| \|---\|---------\|----------\| bit 0 - '0' bit 1 - '0' - unchained, '1' - chained bit 2 - '0' - do not continue on error, '1' - continue on error bit 3 - '0' - next DSS has different correlator, '1' - next DSS has same correlator type - 1 - Request DSS - 2 - Reply DSS - 3 - Object DSS - 4 - Communications DSS - 5 - Request DSS where no reply is expected 2 bytes - request correlation id
protected String	Returns: decrypted string readEncryptedString(DecryptionManager decryption manager decryptM, int security mechanism securityMechanism, byte[] initialization vector for cipher initVector, byte[] public key (as in Deffie-Hellman algorithm) from source (encryptor) sourcePublicKey) Read encrypted string
protected float	Returns: value readFloat(int byteOrder) Read platform float value
protected int	Returns: value readInt(int byteOrder) Read platform int value
protected String	Returns: value readLDStringData(String encoding) Read length delimited string value in DDM data with default encoding
protected int	Returns: - returns codepoint readLengthAndCodePoint(boolean true only when layer B streaming is possible isLayerBStreamingPossible) Read the DDM Length and CodePoint
private ByteArrayInputStream	readLOBChunk(final boolean set to true if the dss continuation should be read readHeader, final long the desired length of chunk. This parameter is ignored when layerB Streaming is doing. desiredLength) This method is used by EXTDTAReaderInputStream to read the next chunk of data.
pack-priv ByteArrayInputStream	readLOBContinuationStream() This method is used by EXTDTAReaderInputStream to read the next chunk of data.
pack-priv ByteArrayInputStream	readLOBContinuationStream(final long the desired length of chunk. This parameter is ignored when layerB Streaming is doing. desiredLength) This method is used by EXTDTAReaderInputStream to read the next chunk of data.
pack-priv ByteArrayInputStream	readLOBInitStream() This method is used by EXTDTAReaderInputStream to read the first chunk of data.
pack-priv ByteArrayInputStream	readLOBInitStream(final long the desired length of chunk. This parameter is ignored when layerB Streaming is doing. desiredLength) This method is used by EXTDTAReaderInputStream to read the first chunk of data.
protected long	Returns: value readLong(int byteOrder) Read platform long value
protected int	Returns: value readNetworkInt() Read network int value
protected long	Returns: value readNetworkLong() Read network long value
protected int	Returns: value readNetworkShort() Read network short value
protected long	Returns: value readNetworkSixByteLong() Read network six byte value and put it in a long v
protected void	readReplyDss() Read Reply DSS This is used in testing the protocol.
protected short	Returns: value readShort(int byteOrder) Read platform short value
protected int	Returns: value readSignedNetworkShort() Read signed network short value
protected String	Returns: value readString(int - length of string to read length) Read string value Strings in DRDA protocol are encoded in EBCDIC by default so we need to convert to UCS2
protected void	readString(DRDAString destination for the read string dst, int size (in bytes) of string to read size, boolean if true, remove padding (trailing spaces) unpad) Read string value into a `DRDAString` object.
protected String	Returns: value readString(int - length of string to read length, String encoding) Read encoded string value
protected String	readString() Read string value
protected String	Returns: value readStringData(int - length of string to read length) Read specified length of string value in DDM data with default encoding
protected int	Returns: value readUnsignedByte() Read byte value and mask out high order bytes before returning
protected void	setEbcdicCcsid()
protected void	setUtf8Ccsid()
private void	shiftBuffer(byte[] - buffer to shift data to destinationBuffer) This is a helper method which shifts the buffered bytes from wherever they are in the current buffer to the beginning of different buffer (note these buffers could be the same).
protected void	skipBytes(int - length of string to skip length) Skip byte string value
protected void	skipBytes() Skip byte string value
protected void	skipDss() Skip remaining DSS
private void	startLayerBStreaming()
protected boolean	terminateChainOnErr()
private void	trace(String msg) Print a internal trace message

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

ADJUST_LENGTHS	back to summary
private static final boolean ADJUST_LENGTHS

agent	back to summary
private DRDAConnThread agent

buffer	back to summary
private byte[] buffer

ccsidManager	back to summary
private CcsidManager ccsidManager

count	back to summary
private int count

ddmCollectionLenStack	back to summary
private long[] ddmCollectionLenStack

ddmScalarLen	back to summary
private long ddmScalarLen

DEFAULT_BUFFER_SIZE	back to summary
private static final int DEFAULT_BUFFER_SIZE

doingLayerBStreaming	back to summary
private boolean doingLayerBStreaming

dssCorrelationID	back to summary
private int dssCorrelationID

dssIsChainedWithDiffID	back to summary
private boolean dssIsChainedWithDiffID

dssIsChainedWithSameID	back to summary
private boolean dssIsChainedWithSameID

dssIsContinued	back to summary
private boolean dssIsContinued

dssLength	back to summary
private int dssLength

dssTrace	back to summary
private DssTrace dssTrace

ebcdicCcsidManager	back to summary
private EbcdicCcsidManager ebcdicCcsidManager

EMPTY_STACK	back to summary
private static final int EMPTY_STACK

inputStream	back to summary
private InputStream inputStream

MAX_EXTDTA_SIZE	back to summary
private static final long MAX_EXTDTA_SIZE

MAX_MARKS_NESTING	back to summary
private static final int MAX_MARKS_NESTING

NO_ADJUST_LENGTHS	back to summary
private static final boolean NO_ADJUST_LENGTHS

NO_CODEPOINT	back to summary
private static final int NO_CODEPOINT

pos	back to summary
private int pos

prevCorrelationID	back to summary
private int prevCorrelationID

svrcod	back to summary
private int svrcod

tenRadixMagnitude	back to summary
private static final int[][] tenRadixMagnitude

terminateChainOnErr	back to summary
private boolean terminateChainOnErr

topDdmCollectionStack	back to summary
private int topDdmCollectionStack

totalByteCount	back to summary
pack-priv volatile long totalByteCount

utf8CcsidManager	back to summary
private Utf8CcsidManager utf8CcsidManager

DDMReader	back to summary
pack-priv DDMReader(DRDAConnThread agent, DssTrace dssTrace)

DDMReader	back to summary
pack-priv DDMReader(InputStream inputStream) This constructor is used for testing the protocol It is used by ProtocolTestAdapter to read the protocol returned by the server

Method Detail

adjustLengths	back to summary
private void adjustLengths(int length) Adjust remaining length Parameters length:int - adjustment length

adjustLengths

back to summary

private void adjustLengths(int length)

Adjust remaining length

Parameters

length:int: - adjustment length

clearBuffer	back to summary
protected void clearBuffer() throws DRDAProtocolException

compressBLayerData	back to summary
private void compressBLayerData(int continueDssHeaderCount) throws DRDAProtocolException Compress B Layer data if extended total length is used by removing the continuation headers Parameters continueDssHeaderCount:int - amount of data we need

compressBLayerData

back to summary

private void compressBLayerData(int continueDssHeaderCount) throws DRDAProtocolException

Compress B Layer data if extended total length is used by removing the continuation headers

Parameters

continueDssHeaderCount:int: - amount of data we need

computeMagnitude	back to summary
private int[] computeMagnitude(int[] input) Compute the int array of magnitude from input value segments. Parameters input:int[] value segments Returns:int[] array of int magnitudes

computeMagnitude

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private int[] computeMagnitude(int[] input)

Compute the int array of magnitude from input value segments.

Parameters

input:int[]: value segments

Returns:int[]

array of int magnitudes

convertBytes	back to summary
protected String convertBytes(byte[] buf) Convert EBCDIC byte array to unicode string Parameters buf:byte[] - byte array Returns:String string

convertBytes

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protected String convertBytes(byte[] buf)

Convert EBCDIC byte array to unicode string

Parameters

buf:byte[]: - byte array

Returns:String

string

doingLayerBStreaming	back to summary
pack-priv boolean doingLayerBStreaming()

ensureALayerDataInBuffer	back to summary
private void ensureALayerDataInBuffer(int desiredDataSize) throws DRDAProtocolException Make sure a certain amount of Layer A data is in the buffer. The data will be in the buffer after this method is called. Parameters desiredDataSize:int - amount of data we need

ensureALayerDataInBuffer

back to summary

private void ensureALayerDataInBuffer(int desiredDataSize) throws DRDAProtocolException

Make sure a certain amount of Layer A data is in the buffer. The data will be in the buffer after this method is called.

Parameters

desiredDataSize:int: - amount of data we need

ensureBLayerDataInBuffer	back to summary
private void ensureBLayerDataInBuffer(int desiredDataSize, boolean adjustLen) throws DRDAProtocolException Make sure a certain amount of Layer B data is in the buffer. The data will be in the buffer after this method is called. Parameters desiredDataSize:int - amount of data we need adjustLen:boolean - whether to adjust the remaining lengths Exceptions DRDAProtocolException: if a protocol error is detected

ensureBLayerDataInBuffer

back to summary

private void ensureBLayerDataInBuffer(int desiredDataSize, boolean adjustLen) throws DRDAProtocolException

Make sure a certain amount of Layer B data is in the buffer. The data will be in the buffer after this method is called.

Parameters

desiredDataSize:int: - amount of data we need
adjustLen:boolean: - whether to adjust the remaining lengths

Exceptions

DRDAProtocolException:: if a protocol error is detected

ensureSpaceInBufferForFill	back to summary
private void ensureSpaceInBufferForFill(int desiredSpace) This method makes sure there is enough room in the buffer for a certain number of bytes. This method will allocate a new buffer if needed and shift the bytes in the current buffer to make ensure space is available for a fill. Right now this method will shift bytes as needed to make sure there is as much room as possible in the buffer before trying to do the read. The idea is to try to have space to get as much data as possible if we need to do a read on the socket's stream. Parameters desiredSpace:int - amount of data we need

ensureSpaceInBufferForFill

back to summary

private void ensureSpaceInBufferForFill(int desiredSpace)

This method makes sure there is enough room in the buffer for a certain number of bytes. This method will allocate a new buffer if needed and shift the bytes in the current buffer to make ensure space is available for a fill. Right now this method will shift bytes as needed to make sure there is as much room as possible in the buffer before trying to do the read. The idea is to try to have space to get as much data as possible if we need to do a read on the socket's stream.

Parameters

desiredSpace:int: - amount of data we need

fill	back to summary
private void fill(int minimumBytesNeeded) throws DRDAProtocolException This method will attempt to read a minimum number of bytes from the underlying stream. This method will keep trying to read bytes until it has obtained at least the minimum number. Parameters minimumBytesNeeded:int - minimum required bytes Exceptions DRDAProtocolException: if a protocol error is detected

fill

back to summary

private void fill(int minimumBytesNeeded) throws DRDAProtocolException

This method will attempt to read a minimum number of bytes from the underlying stream. This method will keep trying to read bytes until it has obtained at least the minimum number.

Parameters

minimumBytesNeeded:int: - minimum required bytes

Exceptions

DRDAProtocolException:: if a protocol error is detected

finishLayerBStreaming	back to summary
private void finishLayerBStreaming()

getCodePoint	back to summary
protected int getCodePoint() throws DRDAProtocolException Get the next CodePoint from a collection Returns:int NO_CODEPOINT if collection stack is empty or remaining length is 0; otherwise, read length and code point Exceptions DRDAProtocolException: if a protocol error is detected

getCodePoint

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protected int getCodePoint() throws DRDAProtocolException

Get the next CodePoint from a collection

Returns:int

NO_CODEPOINT if collection stack is empty or remaining length is 0; otherwise, read length and code point

Exceptions

DRDAProtocolException:: if a protocol error is detected

getCodePoint	back to summary
protected int getCodePoint(int codePointCheck) throws DRDAProtocolException Get the next CodePoint from a collection and check that it matches the specified CodePoint Parameters codePointCheck:int - codePoint to check against Returns:int codePoint Exceptions DRDAProtocolException: if a protocol error is detected

getCodePoint

back to summary

protected int getCodePoint(int codePointCheck) throws DRDAProtocolException

Get the next CodePoint from a collection and check that it matches the specified CodePoint

Parameters

codePointCheck:int: - codePoint to check against

Returns:int

codePoint

Exceptions

DRDAProtocolException:: if a protocol error is detected

getCurrChainState	back to summary
protected byte getCurrChainState() Return chaining bit for current DSS.

getDdmLength	back to summary
protected long getDdmLength() Length of current DDM object Returns:long length of DDM object

getDdmLength

back to summary

protected long getDdmLength()

Length of current DDM object

Returns:long: length of DDM object

getExtData	back to summary
pack-priv byte[] getExtData(long desiredLength, boolean checkNullability) throws DRDAProtocolException

getEXTDTAReaderInputStream

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pack-priv EXTDTAReaderInputStream getEXTDTAReaderInputStream(final boolean checkNullability) throws DRDAProtocolException

Creates an InputStream which can stream EXTDTA objects. The InputStream uses this DDMReader to read data from network. The DDMReader should not be used before all data in the stream has been read.

Parameters

checkNullability:boolean: used to check if the stream is null. If it is null, this method returns null

Returns:EXTDTAReaderInputStream

EXTDTAReaderInputStream object which can be passed to prepared statement as a binary stream.

Exceptions

DRDAProtocolException:: standard DRDA protocol exception

initialize	back to summary
protected void initialize(DRDAConnThread agent, DssTrace dssTrace) Initialize values for this session, the reader is reused so we need to set null and 0 values

isChainedWithDiffID

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protected boolean isChainedWithDiffID()

Next DSS has different correlator than current DSS

Returns:boolean: true if next DSS has a different correlator than current DSS

isChainedWithSameID

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protected boolean isChainedWithSameID()

Next DSS has same correlator as current DSS

Returns:boolean: true if next DSS has the same correlator as current DSS

isCmd

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protected boolean isCmd() throws DRDAProtocolException, UnsupportedEncodingException

Check for the command protocol

Returns:boolean

true if this is a command; false otherwise

Exceptions

DRDAProtocolException:: if a protocol error is detected

isEXTDTANull	back to summary
private boolean isEXTDTANull() throws DRDAProtocolException

markCollection	back to summary
protected void markCollection() Push DDM Length on to collection stack

moreData

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protected boolean moreData()

Is there more data in the buffer

Returns:boolean: true if there is more data in the buffer

moreDdmData

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protected boolean moreDdmData()

Is there more in this DDM object

Returns:boolean: true if DDM length is > 0

moreDssData

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protected boolean moreDssData()

Is there more in this DDS object

Returns:boolean: true if DDS length is > 0

packedNybblesToInt

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private int packedNybblesToInt(byte[] buffer, int offset, int startNybble, int numberOfNybbles)

Convert a range of packed nybbles (up to 9 digits without overflow) to an int. Note that for performance purpose, it does not do array-out-of-bound checking.

Parameters

buffer:byte[]: buffer to read from
offset:int: offset in the buffer
startNybble:int: start nybble
numberOfNybbles:int: number of nybbles

Returns:int

an int value

packedNybblesToLong

back to summary

private long packedNybblesToLong(byte[] buffer, int offset, int startNybble, int numberOfNybbles)

Convert a range of packed nybbles (up to 18 digits without overflow) to a long. Note that for performance purpose, it does not do array-out-of-bound checking.

Parameters

buffer:byte[]: buffer to read from
offset:int: offset in the buffer
startNybble:int: start nybble
numberOfNybbles:int: number of nybbles

Returns:long

an long value

readBigDecimal

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protected BigDecimal readBigDecimal(int precision, int scale) throws DRDAProtocolException

Read a BigDecimal value

Parameters

precision:int: of the BigDecimal
scale:int: of the BigDecimal

Returns:BigDecimal

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readByte

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protected byte readByte() throws DRDAProtocolException

Read byte value

Returns:byte

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readBytes

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protected byte[] readBytes(int length) throws DRDAProtocolException

Read byte string value

Parameters

length:int: - length of string to read

Returns:byte[]

byte array

Exceptions

DRDAProtocolException:: if a protocol error is detected

readBytes

back to summary

protected byte[] readBytes() throws DRDAProtocolException

Read byte string value

Returns:byte[]

byte array

Exceptions

DRDAProtocolException:: if a protocol error is detected

readCmdString

back to summary

protected String readCmdString(int length) throws DRDAProtocolException, UnsupportedEncodingException

Read string value

Parameters

length:int: - length of string to read

Returns:String

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readCmdString

back to summary

protected String readCmdString() throws DRDAProtocolException, UnsupportedEncodingException

Read string value

Returns:String

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readCodePoint

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protected int readCodePoint()

Read the CodePoint

Returns:int: - returns codepoint

readDouble

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protected double readDouble(int byteOrder) throws DRDAProtocolException

Read platform double value

Returns:double

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readDSSContinuationHeader	back to summary
private void readDSSContinuationHeader() throws DRDAProtocolException

readDssHeader

back to summary

protected int readDssHeader() throws DRDAProtocolException

Read DSS header DSS Header format is 2 bytes - length 1 byte - 'D0' - indicates DDM data 1 byte - DSS format |---|---------|----------| | 0 | flags | type | |---|---------|----------| | 0 | 1 2 3 | 4 5 6 7 | |---|---------|----------| bit 0 - '0' bit 1 - '0' - unchained, '1' - chained bit 2 - '0' - do not continue on error, '1' - continue on error bit 3 - '0' - next DSS has different correlator, '1' - next DSS has same correlator type - 1 - Request DSS - 2 - Reply DSS - 3 - Object DSS - 4 - Communications DSS - 5 - Request DSS where no reply is expected 2 bytes - request correlation id

Exceptions

DRDAProtocolException:: if a protocol error is detected

readEncryptedString

back to summary

protected String readEncryptedString(DecryptionManager decryptM, int securityMechanism, byte[] initVector, byte[] sourcePublicKey) throws DRDAProtocolException, SQLException

Read encrypted string

Parameters

decryptM:DecryptionManager: decryption manager
securityMechanism:int: security mechanism
initVector:byte[]: initialization vector for cipher
sourcePublicKey:byte[]: public key (as in Deffie-Hellman algorithm) from source (encryptor)

Returns:String

decrypted string

Exceptions

DRDAProtocolException:: if a protocol error is detected
SQLException:: wrapping any exception in decryption

readFloat

back to summary

protected float readFloat(int byteOrder) throws DRDAProtocolException

Read platform float value

Returns:float

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readInt

back to summary

protected int readInt(int byteOrder) throws DRDAProtocolException

Read platform int value

Returns:int

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readLDStringData

back to summary

protected String readLDStringData(String encoding) throws DRDAProtocolException

Read length delimited string value in DDM data with default encoding

Returns:String

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readLengthAndCodePoint

back to summary

protected int readLengthAndCodePoint(boolean isLayerBStreamingPossible) throws DRDAProtocolException

Read the DDM Length and CodePoint

Parameters

isLayerBStreamingPossible:boolean: true only when layer B streaming is possible

Returns:int

- returns codepoint

Exceptions

DRDAProtocolException:: if a protocol error is detected

readLOBChunk

back to summary

private ByteArrayInputStream readLOBChunk(final boolean readHeader, final long desiredLength) throws DRDAProtocolException

This method is used by EXTDTAReaderInputStream to read the next chunk of data. Furthermore, when Layer B streaming is carried out, calling this method may finish layer B streaming.

Parameters

readHeader:boolean: set to true if the dss continuation should be read
desiredLength:long: the desired length of chunk. This parameter is ignored when layerB Streaming is doing.

Exceptions

DRDAProtocolException:: standard DRDA protocol exception

readLOBContinuationStream

back to summary

pack-priv ByteArrayInputStream readLOBContinuationStream() throws IOException

This method is used by EXTDTAReaderInputStream to read the next chunk of data. Calling this method finishes layer B streaming if continuation of DSS segment was finished. This lengthless method must be called only when layer B streaming.

Exceptions

IOException:: IOException

readLOBContinuationStream

back to summary

pack-priv ByteArrayInputStream readLOBContinuationStream(final long desiredLength) throws IOException

This method is used by EXTDTAReaderInputStream to read the next chunk of data. Furthermore, when Layer B streaming is carried out, calling this method finishes layer B streaming if continuation of DSS segment was finished.

Parameters

desiredLength:long: the desired length of chunk. This parameter is ignored when layerB Streaming is doing.

Exceptions

IOException:: IOException

readLOBInitStream

back to summary

pack-priv ByteArrayInputStream readLOBInitStream() throws DRDAProtocolException

This method is used by EXTDTAReaderInputStream to read the first chunk of data. This lengthless method must be called only when layer B streaming.

Exceptions

DRDAProtocolException:: standard DRDA protocol exception

readLOBInitStream

back to summary

pack-priv ByteArrayInputStream readLOBInitStream(final long desiredLength) throws DRDAProtocolException

This method is used by EXTDTAReaderInputStream to read the first chunk of data.

Parameters

desiredLength:long: the desired length of chunk. This parameter is ignored when layerB Streaming is doing.

Exceptions

DRDAProtocolException:: standard DRDA protocol exception

readLong

back to summary

protected long readLong(int byteOrder) throws DRDAProtocolException

Read platform long value

Returns:long

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readNetworkInt

back to summary

protected int readNetworkInt() throws DRDAProtocolException

Read network int value

Returns:int

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readNetworkLong

back to summary

protected long readNetworkLong() throws DRDAProtocolException

Read network long value

Returns:long

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readNetworkShort

back to summary

protected int readNetworkShort() throws DRDAProtocolException

Read network short value

Returns:int

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readNetworkSixByteLong

back to summary

protected long readNetworkSixByteLong() throws DRDAProtocolException

Read network six byte value and put it in a long v

Returns:long

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readReplyDss

back to summary

protected void readReplyDss() throws DRDAProtocolException

Read Reply DSS This is used in testing the protocol. We shouldn't see a reply DSS when we are servicing DRDA commands

Exceptions

DRDAProtocolException:: if a protocol error is detected

readShort

back to summary

protected short readShort(int byteOrder) throws DRDAProtocolException

Read platform short value

Returns:short

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readSignedNetworkShort

back to summary

protected int readSignedNetworkShort() throws DRDAProtocolException

Read signed network short value

Returns:int

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readString

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protected String readString(int length) throws DRDAProtocolException

Read string value Strings in DRDA protocol are encoded in EBCDIC by default so we need to convert to UCS2

Parameters

length:int: - length of string to read

Returns:String

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readString back to summary

protected void readString(DRDAString dst, int size, boolean unpad) throws DRDAProtocolException

Read string value into a DRDAString object.

Parameters

dst:DRDAString: destination for the read string
size:int: size (in bytes) of string to read
unpad:boolean: if true, remove padding (trailing spaces)

readString

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protected String readString(int length, String encoding) throws DRDAProtocolException

Read encoded string value

Parameters

length:int: - length of string to read

Returns:String

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readString

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protected String readString() throws DRDAProtocolException

Read string value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readStringData

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protected String readStringData(int length) throws DRDAProtocolException

Read specified length of string value in DDM data with default encoding

Parameters

length:int: - length of string to read

Returns:String

value

Exceptions

DRDAProtocolException:: if a protocol error is detected

readUnsignedByte

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protected int readUnsignedByte() throws DRDAProtocolException

Read byte value and mask out high order bytes before returning

Returns:int: value

setEbcdicCcsid	back to summary
protected void setEbcdicCcsid()

setUtf8Ccsid	back to summary
protected void setUtf8Ccsid()

shiftBuffer

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private void shiftBuffer(byte[] destinationBuffer)

This is a helper method which shifts the buffered bytes from wherever they are in the current buffer to the beginning of different buffer (note these buffers could be the same). State information is updated as needed after the shift.

Parameters

destinationBuffer:byte[]: - buffer to shift data to

skipBytes

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protected void skipBytes(int length) throws DRDAProtocolException

Skip byte string value

Parameters

length:int: - length of string to skip

Exceptions

DRDAProtocolException:: if a protocol error is detected

skipBytes	back to summary
protected void skipBytes() throws DRDAProtocolException Skip byte string value

skipDss	back to summary
protected void skipDss() throws DRDAProtocolException Skip remaining DSS

startLayerBStreaming	back to summary
private void startLayerBStreaming()

terminateChainOnErr	back to summary
protected boolean terminateChainOnErr()

trace	back to summary
private void trace(String msg) Print a internal trace message

pack-priv Class DDMReader

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