org.postgresql.copy

Class PGCopyOutputStream

java.lang.Object

java.io.OutputStream

org.postgresql.copy.PGCopyOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable, CopyIn, CopyOperation

public class PGCopyOutputStream
extends OutputStream
implements CopyIn

OutputStream for buffered input into a PostgreSQL COPY FROM STDIN operation.

Constructor Summary

Constructors

Constructor and Description
PGCopyOutputStream(CopyIn op) Use given CopyIn operation for writing.
PGCopyOutputStream(CopyIn op, int bufferSize) Use given CopyIn operation for writing.
PGCopyOutputStream(PGConnection connection, String sql) Uses given connection for specified COPY FROM STDIN operation.
PGCopyOutputStream(PGConnection connection, String sql, int bufferSize) Uses given connection for specified COPY FROM STDIN operation.

Method Summary

Methods

Modifier and Type	Method and Description
void	cancelCopy() Cancels this copy operation, discarding any exchanged data.
void	close() Closes this output stream and releases any system resources associated with this stream.
long	endCopy() Finishes copy operation successfully.
void	flush() Flushes this output stream and forces any buffered output bytes to be written out.
void	flushCopy() Force any buffered output to be sent over the network to the backend.
int	getFieldCount()
int	getFieldFormat(int field)
int	getFormat()
long	getHandledRowCount() After successful end of copy, returns the number of database records handled in that operation.
boolean	isActive()
void	write(byte[] buf) Writes b.length bytes from the specified byte array to this output stream.
void	write(byte[] buf, int off, int siz) Writes len bytes from the specified byte array starting at offset off to this output stream.
void	write(int b) Writes the specified byte to this output stream.
void	writeToCopy(byte[] buf, int off, int siz) Writes specified part of given byte array to an open and writable copy operation.

Methods inherited from class java.lang.Object

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

Constructor Detail

PGCopyOutputStream

public PGCopyOutputStream(PGConnection connection,
                  String sql)
                   throws SQLException

Uses given connection for specified COPY FROM STDIN operation.

Parameters:

connection - database connection to use for copying (protocol version 3 required)

sql - COPY FROM STDIN statement

Throws:

SQLException - if initializing the operation fails

PGCopyOutputStream

public PGCopyOutputStream(PGConnection connection,
                  String sql,
                  int bufferSize)
                   throws SQLException

Uses given connection for specified COPY FROM STDIN operation.

Parameters:

connection - database connection to use for copying (protocol version 3 required)

sql - COPY FROM STDIN statement

bufferSize - try to send this many bytes at a time

Throws:

SQLException - if initializing the operation fails

PGCopyOutputStream

public PGCopyOutputStream(CopyIn op)

Use given CopyIn operation for writing.

Parameters:

op - COPY FROM STDIN operation

PGCopyOutputStream

public PGCopyOutputStream(CopyIn op,
                  int bufferSize)

Use given CopyIn operation for writing.

Parameters:

op - COPY FROM STDIN operation

bufferSize - try to send this many bytes at a time

Method Detail

write

public void write(int b)
           throws IOException

Description copied from class: java.io.OutputStream

Writes the specified byte to this output stream. The general contract for write is that one byte is written to the output stream. The byte to be written is the eight low-order bits of the argument b. The 24 high-order bits of b are ignored.

Subclasses of OutputStream must provide an implementation for this method.

Specified by:

write in class OutputStream

Parameters:

b - the byte.

Throws:

IOException - if an I/O error occurs. In particular, an IOException may be thrown if the output stream has been closed.

write

public void write(byte[] buf)
           throws IOException

Description copied from class: java.io.OutputStream

Writes b.length bytes from the specified byte array to this output stream. The general contract for write(b) is that it should have exactly the same effect as the call write(b, 0, b.length).

Overrides:

write in class OutputStream

Parameters:

buf - the data.

Throws:

IOException - if an I/O error occurs.

See Also:

OutputStream.write(byte[], int, int)

write

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

Description copied from class: java.io.OutputStream

Writes len bytes from the specified byte array starting at offset off to this output stream. The general contract for write(b, off, len) is that some of the bytes in the array b are written to the output stream in order; element b[off] is the first byte written and b[off+len-1] is the last byte written by this operation.

The write method of OutputStream calls the write method of one argument on each of the bytes to be written out. Subclasses are encouraged to override this method and provide a more efficient implementation.

If b is null, a NullPointerException is thrown.

If off is negative, or len is negative, or off+len is greater than the length of the array b, then an IndexOutOfBoundsException is thrown.

Overrides:

write in class OutputStream

Parameters:

buf - the data.

off - the start offset in the data.

siz - the number of bytes to write.

Throws:

IOException - if an I/O error occurs. In particular, an IOException is thrown if the output stream is closed.

close

public void close()
           throws IOException

Description copied from class: java.io.OutputStream

Closes this output stream and releases any system resources associated with this stream. The general contract of close is that it closes the output stream. A closed stream cannot perform output operations and cannot be reopened.

The close method of OutputStream does nothing.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class OutputStream

Throws:

IOException - if an I/O error occurs.

flush

public void flush()
           throws IOException

Description copied from class: java.io.OutputStream

Flushes this output stream and forces any buffered output bytes to be written out. The general contract of flush is that calling it is an indication that, if any bytes previously written have been buffered by the implementation of the output stream, such bytes should immediately be written to their intended destination.

If the intended destination of this stream is an abstraction provided by the underlying operating system, for example a file, then flushing the stream guarantees only that bytes previously written to the stream are passed to the operating system for writing; it does not guarantee that they are actually written to a physical device such as a disk drive.

The flush method of OutputStream does nothing.

Specified by:

flush in interface Flushable

Overrides:

flush in class OutputStream

Throws:

IOException - if an I/O error occurs.

writeToCopy

public void writeToCopy(byte[] buf,
               int off,
               int siz)
                 throws SQLException

Description copied from interface: CopyIn

Writes specified part of given byte array to an open and writable copy operation.

Specified by:

writeToCopy in interface CopyIn

Parameters:

buf - array of bytes to write

off - offset of first byte to write (normally zero)

siz - number of bytes to write (normally buf.length)

Throws:

SQLException - if the operation fails

getFormat

public int getFormat()

Specified by:

getFormat in interface CopyOperation

Returns:

overall format of each row: 0 = textual, 1 = binary

getFieldFormat

public int getFieldFormat(int field)

Specified by:

getFieldFormat in interface CopyOperation

Parameters:

field - number of field (0..fieldCount()-1)

Returns:

format of requested field: 0 = textual, 1 = binary

cancelCopy

public void cancelCopy()
                throws SQLException

Description copied from interface: CopyOperation

Cancels this copy operation, discarding any exchanged data.

Specified by:

cancelCopy in interface CopyOperation

Throws:

SQLException - if cancelling fails

getFieldCount

public int getFieldCount()

Specified by:

getFieldCount in interface CopyOperation

Returns:

number of fields in each row for this operation

isActive

public boolean isActive()

Specified by:

isActive in interface CopyOperation

Returns:

is connection reserved for this Copy operation?

flushCopy

public void flushCopy()
               throws SQLException

Description copied from interface: CopyIn

Force any buffered output to be sent over the network to the backend. In general this is a useless operation as it will get pushed over in due time or when endCopy is called. Some specific modified server versions (Truviso) want this data sooner. If you are unsure if you need to use this method, don't.

Specified by:

flushCopy in interface CopyIn

Throws:

SQLException - if the operation fails.

endCopy

public long endCopy()
             throws SQLException

Description copied from interface: CopyIn

Finishes copy operation successfully.

Specified by:

endCopy in interface CopyIn

Returns:

number of updated rows for server 8.2 or newer (see getHandledRowCount())

Throws:

SQLException - if the operation fails.

getHandledRowCount

public long getHandledRowCount()

Description copied from interface: CopyOperation

After successful end of copy, returns the number of database records handled in that operation. Only implemented in PostgreSQL server version 8.2 and up. Otherwise, returns -1.

Specified by:

getHandledRowCount in interface CopyOperation

Returns:

number of handled rows or -1