PostgreSQL JDBC Driver 42.7.2 · org.postgresql.core.PGStream

Modifier and Type	Field and Description
private Socket	connection
private Encoding	encoding
private Writer	encodingWriter
pack-priv boolean	gssEncrypted
private final HostSpec	hostSpec
private final byte[]	int2Buf
private final byte[]	int4Buf
private long	maxResultBuffer
private int	maxRowSizeBytes
private int	minStreamAvailableCheckDelay
private long	nextStreamAvailableCheckTime
private VisibleBufferedInputStream	pgInput
private OutputStream	pgOutput
private long	resultBufferByteCount
private final SocketFactory	socketFactory
private @Nullable byte[]	streamBuffer

Access	Constructor and Description
public	PGStream(SocketFactory socket factory to use when creating sockets socketFactory, HostSpec the host and port to connect to hostSpec, int timeout in milliseconds, or 0 if no timeout set timeout) Constructor: Connect to the PostgreSQL back end and return a stream connection.
public	PGStream(PGStream pgStream, int timeout)
public	PGStream(SocketFactory socket factory socketFactory, HostSpec the host and port to connect to hostSpec) Deprecated use `PGStream(SocketFactory, org.postgresql.util.HostSpec, int)` Constructor: Connect to the PostgreSQL back end and return a stream connection.

Method Summary

Modifier and Type	Method and Description
public void	changeSocket(Socket the new socket to change to socket) Switch this stream to using a new socket.
public void	clearMaxRowSizeBytes() Clear value of max row size noticed so far.
public void	clearResultBufferCount() Clear count of byte buffer.
public void	close() Implements java.io.Closeable.close. Closes the connection.
private Socket	createSocket(int timeout)
public void	flush() Implements java.io.Flushable.flush. Flush any pending output to the backend.
public Encoding	getEncoding()
public Writer	Returns: the shared Writer instance getEncodingWriter() Get a Writer instance that encodes directly onto the underlying stream.
public HostSpec	getHostSpec()
public long	Returns: size of MaxResultBuffer getMaxResultBuffer() Get MaxResultBuffer from PGStream.
public int	Returns: value of max row size getMaxRowSizeBytes() Get actual max row size noticed so far.
public int	getNetworkTimeout()
public Socket	getSocket()
public SocketFactory	getSocketFactory()
public boolean	Returns: true if there is a pending backend message hasMessagePending() Check for pending backend messages without blocking.
private void	increaseByteCounter(long size of bytes to add to byte buffer. value) Increase actual count of buffer.
public boolean	isClosed()
public boolean	isGssEncrypted()
public int	Returns: the character received peekChar() Receives a single character from the backend, without advancing the current protocol stream position.
public byte[]	Returns: array of bytes received receive(int number of bytes to read siz) Reads in a given number of bytes from the backend.
public void	receive(byte[] buffer to store result buf, int offset in buffer off, int number of bytes to read siz) Reads in a given number of bytes from the backend.
public String	Returns: string from back end receiveCanonicalString() Receives a null-terminated string from the backend and attempts to decode to a `canonical` `String`.
public String	Returns: string from back end receiveCanonicalStringIfPresent() Receives a null-terminated string from the backend and attempts to decode to a `canonical` `String`.
public int	Returns: the character received receiveChar() Receives a single character from the backend.
public void	receiveEOF() Consume an expected EOF from the backend.
public EncodingPredictor.DecodeResult	Returns: the decoded string receiveErrorString(int the length of the string to receive, in bytes. len) Receives a fixed-size string from the backend, and tries to avoid "UTF-8 decode failed" errors.
public int	Returns: the integer received from the backend receiveInteger2() Receives a two byte integer from the backend.
public int	Returns: the integer received from the backend receiveInteger4() Receives a four byte integer from the backend.
public String	Returns: the decoded string receiveString(int the length of the string to receive, in bytes. len) Receives a fixed-size string from the backend.
public String	Returns: string from back end receiveString() Receives a null-terminated string from the backend.
public Tuple	Returns: tuple from the back end receiveTupleV3() Read a tuple from the back end.
public void	send(byte[] The array of bytes to be sent buf) Send an array of bytes to the backend.
public void	send(byte[] the array of bytes to be sent buf, int the number of bytes to be sent siz) Send a fixed-size array of bytes to the backend.
public void	send(byte[] the array of bytes to be sent buf, int offset in the array to start sending from off, int the number of bytes to be sent siz) Send a fixed-size array of bytes to the backend.
public void	send(ByteStreamWriter the stream writer to invoke to send the bytes writer) Send a fixed-size array of bytes to the backend.
public void	sendChar(int the character to be sent val) Sends a single character to the back end.
public void	sendInteger2(int the integer to be sent val) Sends a 2-byte integer (short) to the back end.
public void	sendInteger4(int the integer to be sent val) Sends a 4-byte integer to the back end.
public void	sendStream(InputStream the stream to read data from inStream, int the number of bytes to copy remaining) Copy data from an input stream to the connection.
public void	setEncoding(Encoding the new encoding to use encoding) Change the encoding used by this connection.
public void	setMaxResultBuffer(@Nullable String value of new max result buffer as string (cause we can expect % or chars to use multiplier) value) Method to set MaxResultBuffer inside PGStream.
public void	setMaxRowSizeBytes(int new value to be set as maxRowSizeBytes rowSizeBytes) The idea behind this method is to keep in maxRowSize the size of biggest read data row.
public void	setMinStreamAvailableCheckDelay(int delay)
public void	setNetworkTimeout(int milliseconds)
public void	setSecContext(GSSContext secContext)
public void	skip(int size)

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

connection	back to summary
private Socket connection

encoding	back to summary
private Encoding encoding

encodingWriter	back to summary
private Writer encodingWriter

gssEncrypted	back to summary
pack-priv boolean gssEncrypted

hostSpec	back to summary
private final HostSpec hostSpec

int2Buf	back to summary
private final byte[] int2Buf

int4Buf	back to summary
private final byte[] int4Buf

maxResultBuffer	back to summary
private long maxResultBuffer

maxRowSizeBytes	back to summary
private int maxRowSizeBytes

minStreamAvailableCheckDelay	back to summary
private int minStreamAvailableCheckDelay

nextStreamAvailableCheckTime	back to summary
private long nextStreamAvailableCheckTime

pgInput	back to summary
private VisibleBufferedInputStream pgInput

pgOutput	back to summary
private OutputStream pgOutput

resultBufferByteCount	back to summary
private long resultBufferByteCount

socketFactory	back to summary
private final SocketFactory socketFactory

streamBuffer	back to summary
private @Nullable byte[] streamBuffer

PGStream	back to summary
public PGStream(SocketFactory socketFactory, HostSpec hostSpec, int timeout) throws IOException Constructor: Connect to the PostgreSQL back end and return a stream connection. Parameters socketFactory:SocketFactory socket factory to use when creating sockets hostSpec:HostSpec the host and port to connect to timeout:int timeout in milliseconds, or 0 if no timeout set Annotations @SuppressWarnings:method.invocation, initialization.fields.uninitialized Exceptions IOException: if an IOException occurs below it.

PGStream	back to summary
public PGStream(PGStream pgStream, int timeout) throws IOException Annotations @SuppressWarnings:method.invocation, initialization.fields.uninitialized

PGStream	back to summary
public PGStream(SocketFactory socketFactory, HostSpec hostSpec) throws IOException Deprecated use `PGStream(SocketFactory, org.postgresql.util.HostSpec, int)` Constructor: Connect to the PostgreSQL back end and return a stream connection. Parameters socketFactory:SocketFactory socket factory hostSpec:HostSpec the host and port to connect to Annotations @Deprecated Exceptions IOException: if an IOException occurs below it.

Method Detail

changeSocket	back to summary
public void changeSocket(Socket socket) throws IOException Switch this stream to using a new socket. Any existing socket is not closed; it's assumed that we are changing to a new socket that delegates to the original socket (e.g. SSL). Parameters socket:Socket the new socket to change to Exceptions IOException: if something goes wrong

changeSocket

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public void changeSocket(Socket socket) throws IOException

Switch this stream to using a new socket. Any existing socket is not closed; it's assumed that we are changing to a new socket that delegates to the original socket (e.g. SSL).

Parameters

socket:Socket: the new socket to change to

Exceptions

IOException:: if something goes wrong

clearMaxRowSizeBytes	back to summary
public void clearMaxRowSizeBytes() Clear value of max row size noticed so far.

clearResultBufferCount	back to summary
public void clearResultBufferCount() Clear count of byte buffer.

close	back to summary
public void close() throws IOException Implements java.io.Closeable.close. Closes the connection. Annotations @Override Exceptions IOException: if an I/O Error occurs

back to summary

public void close() throws IOException

Implements java.io.Closeable.close.

Closes the connection.

Annotations

@Override

Exceptions

IOException:: if an I/O Error occurs

createSocket	back to summary
private Socket createSocket(int timeout) throws IOException

flush	back to summary
public void flush() throws IOException Implements java.io.Flushable.flush. Flush any pending output to the backend. Annotations @Override Exceptions IOException: if an I/O error occurs

flush

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public void flush() throws IOException

Implements java.io.Flushable.flush.

Flush any pending output to the backend.

Annotations

@Override

Exceptions

IOException:: if an I/O error occurs

getEncoding	back to summary
public Encoding getEncoding()

getEncodingWriter back to summary

getEncodingWriter	back to summary
public Writer getEncodingWriter() throws IOException Get a Writer instance that encodes directly onto the underlying stream. The returned Writer should not be closed, as it's a shared object. Writer.flush needs to be called when switching between use of the Writer and use of the PGStream write methods, but it won't actually flush output all the way out -- call `flush` to actually ensure all output has been pushed to the server. Returns:Writer the shared Writer instance Exceptions IOException: if something goes wrong.

public Writer getEncodingWriter() throws IOException

Get a Writer instance that encodes directly onto the underlying stream.

The returned Writer should not be closed, as it's a shared object. Writer.flush needs to be called when switching between use of the Writer and use of the PGStream write methods, but it won't actually flush output all the way out -- call flush to actually ensure all output has been pushed to the server.

Returns:Writer

the shared Writer instance

Exceptions

IOException:: if something goes wrong.

getHostSpec	back to summary
public HostSpec getHostSpec()

getMaxResultBuffer	back to summary
public long getMaxResultBuffer() Get MaxResultBuffer from PGStream. Returns:long size of MaxResultBuffer

getMaxResultBuffer

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public long getMaxResultBuffer()

Get MaxResultBuffer from PGStream.

Returns:long: size of MaxResultBuffer

getMaxRowSizeBytes	back to summary
public int getMaxRowSizeBytes() Get actual max row size noticed so far. Returns:int value of max row size

getMaxRowSizeBytes

back to summary

public int getMaxRowSizeBytes()

Get actual max row size noticed so far.

Returns:int: value of max row size

getNetworkTimeout	back to summary
public int getNetworkTimeout() throws IOException

getSocket	back to summary
public Socket getSocket()

getSocketFactory	back to summary
public SocketFactory getSocketFactory()

hasMessagePending	back to summary
public boolean hasMessagePending() throws IOException Check for pending backend messages without blocking. Might return false when there actually are messages waiting, depending on the characteristics of the underlying socket. This is used to detect asynchronous notifies from the backend, when available. Returns:boolean true if there is a pending backend message Exceptions IOException: if something wrong happens

hasMessagePending

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public boolean hasMessagePending() throws IOException

Check for pending backend messages without blocking. Might return false when there actually are messages waiting, depending on the characteristics of the underlying socket. This is used to detect asynchronous notifies from the backend, when available.

Returns:boolean

true if there is a pending backend message

Exceptions

IOException:: if something wrong happens

increaseByteCounter	back to summary
private void increaseByteCounter(long value) throws SQLException Increase actual count of buffer. If buffer count is bigger than max result buffer limit, then gonna return an exception. Parameters value:long size of bytes to add to byte buffer. Exceptions SQLException: exception returned when result buffer count is bigger than max result buffer.

increaseByteCounter

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private void increaseByteCounter(long value) throws SQLException

Increase actual count of buffer. If buffer count is bigger than max result buffer limit, then gonna return an exception.

Parameters

value:long: size of bytes to add to byte buffer.

Exceptions

SQLException:: exception returned when result buffer count is bigger than max result buffer.

isClosed	back to summary
public boolean isClosed()

isGssEncrypted	back to summary
public boolean isGssEncrypted()

peekChar	back to summary
public int peekChar() throws IOException Receives a single character from the backend, without advancing the current protocol stream position. Returns:int the character received Exceptions IOException: if an I/O Error occurs

peekChar

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public int peekChar() throws IOException

Receives a single character from the backend, without advancing the current protocol stream position.

Returns:int

the character received

Exceptions

IOException:: if an I/O Error occurs

receive	back to summary
public byte[] receive(int siz) throws IOException Reads in a given number of bytes from the backend. Parameters siz:int number of bytes to read Returns:byte[] array of bytes received Exceptions IOException: if a data I/O error occurs

receive

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public byte[] receive(int siz) throws IOException

Reads in a given number of bytes from the backend.

Parameters

siz:int: number of bytes to read

Returns:byte[]

array of bytes received

Exceptions

IOException:: if a data I/O error occurs

receive	back to summary
public void receive(byte[] buf, int off, int siz) throws IOException Reads in a given number of bytes from the backend. Parameters buf:byte[] buffer to store result off:int offset in buffer siz:int number of bytes to read Exceptions IOException: if a data I/O error occurs

receive

back to summary

public void receive(byte[] buf, int off, int siz) throws IOException

Reads in a given number of bytes from the backend.

Parameters

buf:byte[]: buffer to store result
off:int: offset in buffer
siz:int: number of bytes to read

Exceptions

IOException:: if a data I/O error occurs

receiveCanonicalString back to summary

receiveCanonicalString	back to summary
public String receiveCanonicalString() throws IOException Receives a null-terminated string from the backend and attempts to decode to a `canonical` `String`. If we don't see a null, then we assume something has gone wrong. Returns:String string from back end Exceptions IOException: if an I/O error occurs, or end of file See Also `Encoding#decodeCanonicalized(byte[], int, int)`

public String receiveCanonicalString() throws IOException

Receives a null-terminated string from the backend and attempts to decode to a canonical String. If we don't see a null, then we assume something has gone wrong.

Returns:String

string from back end

Exceptions

IOException:: if an I/O error occurs, or end of file

receiveCanonicalStringIfPresent back to summary

receiveCanonicalStringIfPresent	back to summary
public String receiveCanonicalStringIfPresent() throws IOException Receives a null-terminated string from the backend and attempts to decode to a `canonical` `String`. If we don't see a null, then we assume something has gone wrong. Returns:String string from back end Exceptions IOException: if an I/O error occurs, or end of file See Also `Encoding#decodeCanonicalizedIfPresent(byte[], int, int)`

public String receiveCanonicalStringIfPresent() throws IOException

Receives a null-terminated string from the backend and attempts to decode to a canonical String. If we don't see a null, then we assume something has gone wrong.

Returns:String

string from back end

Exceptions

IOException:: if an I/O error occurs, or end of file

receiveChar	back to summary
public int receiveChar() throws IOException Receives a single character from the backend. Returns:int the character received Exceptions IOException: if an I/O Error occurs

receiveChar

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public int receiveChar() throws IOException

Receives a single character from the backend.

Returns:int

the character received

Exceptions

IOException:: if an I/O Error occurs

receiveEOF	back to summary
public void receiveEOF() throws SQLException, IOException Consume an expected EOF from the backend. Exceptions SQLException: if we get something other than an EOF IOException: if an I/O error occurs

receiveEOF

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public void receiveEOF() throws SQLException, IOException

Consume an expected EOF from the backend.

Exceptions

SQLException:: if we get something other than an EOF
IOException:: if an I/O error occurs

receiveErrorString	back to summary
public EncodingPredictor.DecodeResult receiveErrorString(int len) throws IOException Receives a fixed-size string from the backend, and tries to avoid "UTF-8 decode failed" errors. Parameters len:int the length of the string to receive, in bytes. Returns:EncodingPredictor.DecodeResult the decoded string Exceptions IOException: if something wrong happens

receiveErrorString

back to summary

public EncodingPredictor.DecodeResult receiveErrorString(int len) throws IOException

Receives a fixed-size string from the backend, and tries to avoid "UTF-8 decode failed" errors.

Parameters

len:int: the length of the string to receive, in bytes.

Returns:EncodingPredictor.DecodeResult

the decoded string

Exceptions

IOException:: if something wrong happens

receiveInteger2	back to summary
public int receiveInteger2() throws IOException Receives a two byte integer from the backend. Returns:int the integer received from the backend Exceptions IOException: if an I/O error occurs

receiveInteger2

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public int receiveInteger2() throws IOException

Receives a two byte integer from the backend.

Returns:int

the integer received from the backend

Exceptions

IOException:: if an I/O error occurs

receiveInteger4	back to summary
public int receiveInteger4() throws IOException Receives a four byte integer from the backend. Returns:int the integer received from the backend Exceptions IOException: if an I/O error occurs

receiveInteger4

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public int receiveInteger4() throws IOException

Receives a four byte integer from the backend.

Returns:int

the integer received from the backend

Exceptions

IOException:: if an I/O error occurs

receiveString

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public String receiveString(int len) throws IOException

Receives a fixed-size string from the backend.

Parameters

len:int: the length of the string to receive, in bytes.

Returns:String

the decoded string

Exceptions

IOException:: if something wrong happens

receiveString

back to summary

public String receiveString() throws IOException

Receives a null-terminated string from the backend. If we don't see a null, then we assume something has gone wrong.

Returns:String

string from back end

Exceptions

IOException:: if an I/O error occurs, or end of file

receiveTupleV3

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public Tuple receiveTupleV3() throws IOException, OutOfMemoryError, SQLException

Read a tuple from the back end. A tuple is a two dimensional array of bytes. This variant reads the V3 protocol's tuple representation.

Returns:Tuple

tuple from the back end

Exceptions

IOException:: if a data I/O error occurs
SQLException:: if read more bytes than set maxResultBuffer

send

back to summary

public void send(byte[] buf) throws IOException

Send an array of bytes to the backend.

Parameters

buf:byte[]: The array of bytes to be sent

Exceptions

IOException:: if an I/O error occurs

send back to summary

public void send(byte[] buf, int siz) throws IOException

Send a fixed-size array of bytes to the backend. If buf.length < siz, pad with zeros. If buf.length > siz, truncate the array.

Parameters

buf:byte[]: the array of bytes to be sent
siz:int: the number of bytes to be sent

Exceptions

IOException:: if an I/O error occurs

send back to summary

public void send(byte[] buf, int off, int siz) throws IOException

Send a fixed-size array of bytes to the backend. If length < siz, pad with zeros. If length > siz, truncate the array.

Parameters

buf:byte[]: the array of bytes to be sent
off:int: offset in the array to start sending from
siz:int: the number of bytes to be sent

Exceptions

IOException:: if an I/O error occurs

send back to summary

public void send(ByteStreamWriter writer) throws IOException

Send a fixed-size array of bytes to the backend. If length < siz, pad with zeros. If length > siz, truncate the array.

Parameters

writer:ByteStreamWriter: the stream writer to invoke to send the bytes

Exceptions

IOException:: if an I/O error occurs

sendChar

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public void sendChar(int val) throws IOException

Sends a single character to the back end.

Parameters

val:int: the character to be sent

Exceptions

IOException:: if an I/O error occurs

sendInteger2 back to summary

public void sendInteger2(int val) throws IOException

Sends a 2-byte integer (short) to the back end.

Parameters

val:int: the integer to be sent

Exceptions

IOException:: if an I/O error occurs or val cannot be encoded in 2 bytes

sendInteger4

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public void sendInteger4(int val) throws IOException

Sends a 4-byte integer to the back end.

Parameters

val:int: the integer to be sent

Exceptions

IOException:: if an I/O error occurs

sendStream

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public void sendStream(InputStream inStream, int remaining) throws IOException

Copy data from an input stream to the connection.

Parameters

inStream:InputStream: the stream to read data from
remaining:int: the number of bytes to copy

Exceptions

IOException:: if a data I/O error occurs

setEncoding

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public void setEncoding(Encoding encoding) throws IOException

Change the encoding used by this connection.

Parameters

encoding:Encoding: the new encoding to use

Exceptions

IOException:: if something goes wrong

setMaxResultBuffer

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public void setMaxResultBuffer(@Nullable String value) throws PSQLException

Method to set MaxResultBuffer inside PGStream.

Parameters

value:@Nullable String: value of new max result buffer as string (cause we can expect % or chars to use multiplier)

Exceptions

PSQLException:: exception returned when occurred parsing problem.

setMaxRowSizeBytes

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public void setMaxRowSizeBytes(int rowSizeBytes)

The idea behind this method is to keep in maxRowSize the size of biggest read data row. As there may be many data rows send after each other for a query, then value in maxRowSize would contain value noticed so far, because next data rows and their sizes are not read for that moment. We want it increasing, because the size of the biggest among data rows will be used during computing new adaptive fetch size for the query.

Parameters

rowSizeBytes:int: new value to be set as maxRowSizeBytes

setMinStreamAvailableCheckDelay	back to summary
public void setMinStreamAvailableCheckDelay(int delay)

setNetworkTimeout	back to summary
public void setNetworkTimeout(int milliseconds) throws IOException

setSecContext	back to summary
public void setSecContext(GSSContext secContext)

skip	back to summary
public void skip(int size) throws IOException

public Class PGStream

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail