com.mysql.cj.protocol.a.result

Class ResultsetRowsCursor

java.lang.Object

com.mysql.cj.protocol.a.result.AbstractResultsetRows

com.mysql.cj.protocol.a.result.ResultsetRowsCursor

All Implemented Interfaces:

ProtocolEntity, ResultsetRows, RowList, java.util.Iterator<Row>

public class ResultsetRowsCursor
extends AbstractResultsetRows
implements ResultsetRows

Model for result set data backed by a cursor (see http://dev.mysql.com/doc/refman/5.7/en/cursors.html and SERVER_STATUS_CURSOR_EXISTS flag description on http://dev.mysql.com/doc/internals/en/status-flags.html). Only works for forward-only result sets (but still works with updatable concurrency).

Field Summary

Fields

Modifier and Type	Field and Description
protected NativeMessageBuilder	commandBuilder
private int	currentPositionInEntireResult Where we are positionaly in the entire result set, used mostly to facilitate easy 'isBeforeFirst()' and 'isFirst()' methods.
private java.util.List<Row>	fetchedRows The cache of rows we have retrieved from the server.
private boolean	firstFetchCompleted Have we attempted to fetch any rows yet?
private boolean	lastRowFetched Have we been told from the server that we have seen the last row?
private NativeProtocol	protocol Communications channel to the server

Fields inherited from class com.mysql.cj.protocol.a.result.AbstractResultsetRows

BEFORE_START_OF_ROWS, currentPositionInFetchedRows, metadata, owner, rowFactory, wasEmpty

Fields inherited from interface com.mysql.cj.result.RowList

RESULT_SET_SIZE_UNKNOWN

Constructor Summary

Constructors

Constructor and Description
ResultsetRowsCursor(NativeProtocol ioChannel, ColumnDefinition columnDefinition) Creates a new cursor-backed row provider.

Method Summary

Modifier and Type	Method and Description
void	addRow(Row row) Adds a row.
void	afterLast() Moves to after last.
void	beforeFirst() Moves to before first.
void	beforeLast() Moves to before last.
void	close() We're done.
private void	fetchMoreRows()
int	getPosition() Returns the current position.
boolean	hasNext()
boolean	isAfterLast() Returns true if we got the last element.
boolean	isBeforeFirst() Returns if iteration has not occured yet.
boolean	isEmpty() Has no records.
boolean	isFirst() Are we on the first row of the result set?
boolean	isLast() Are we on the last row of the result set?
void	moveRowRelative(int rows) Moves the current position relative 'rows' from the current position.
Row	next()
void	setCurrentRow(int rowNumber) Moves the current position in the result set to the given row number.

Methods inherited from class com.mysql.cj.protocol.a.result.AbstractResultsetRows

getMetadata, getOwner, setMetadata, setOwner, wasEmpty

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.mysql.cj.protocol.ResultsetRows

getMetadata, getOwner, isDynamic, setMetadata, setOwner, wasEmpty

Methods inherited from interface com.mysql.cj.result.RowList

get, previous, size

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Field Detail

fetchedRows

private java.util.List<Row> fetchedRows

The cache of rows we have retrieved from the server.

currentPositionInEntireResult

private int currentPositionInEntireResult

Where we are positionaly in the entire result set, used mostly to facilitate easy 'isBeforeFirst()' and 'isFirst()' methods.

lastRowFetched

private boolean lastRowFetched

Have we been told from the server that we have seen the last row?

protocol

private NativeProtocol protocol

Communications channel to the server

firstFetchCompleted

private boolean firstFetchCompleted

Have we attempted to fetch any rows yet?

commandBuilder

protected NativeMessageBuilder commandBuilder

Constructor Detail

ResultsetRowsCursor

public ResultsetRowsCursor(NativeProtocol ioChannel,
                           ColumnDefinition columnDefinition)

Creates a new cursor-backed row provider.

Parameters:

ioChannel - connection to the server.

columnDefinition - field-level metadata for the results that this cursor covers.

Method Detail

isAfterLast

public boolean isAfterLast()

Description copied from interface: ResultsetRows

Returns true if we got the last element.

Specified by:

isAfterLast in interface ResultsetRows

Returns:

true if after last row

isBeforeFirst

public boolean isBeforeFirst()

Description copied from interface: ResultsetRows

Returns if iteration has not occured yet.

Specified by:

isBeforeFirst in interface ResultsetRows

Returns:

true if before first row

getPosition

public int getPosition()

Description copied from interface: RowList

Returns the current position.

Specified by:

getPosition in interface RowList

Returns:

the current row number

isEmpty

public boolean isEmpty()

Description copied from interface: ResultsetRows

Has no records.

Specified by:

isEmpty in interface ResultsetRows

Returns:

true if no records

isFirst

public boolean isFirst()

Description copied from interface: ResultsetRows

Are we on the first row of the result set?

Specified by:

isFirst in interface ResultsetRows

Returns:

true if on first row

isLast

public boolean isLast()

Description copied from interface: ResultsetRows

Are we on the last row of the result set?

Specified by:

isLast in interface ResultsetRows

Returns:

true if on last row

close

public void close()

Description copied from interface: ResultsetRows

We're done.

Specified by:

close in interface ResultsetRows

hasNext

public boolean hasNext()

Specified by:

hasNext in interface java.util.Iterator<Row>

next

public Row next()

Specified by:

next in interface java.util.Iterator<Row>

fetchMoreRows

private void fetchMoreRows()

addRow

public void addRow(Row row)

Description copied from interface: ResultsetRows

Adds a row.

Specified by:

addRow in interface ResultsetRows

Parameters:

row - the row to add

afterLast

public void afterLast()

Description copied from interface: ResultsetRows

Moves to after last.

Specified by:

afterLast in interface ResultsetRows

beforeFirst

public void beforeFirst()

Description copied from interface: ResultsetRows

Moves to before first.

Specified by:

beforeFirst in interface ResultsetRows

beforeLast

public void beforeLast()

Description copied from interface: ResultsetRows

Moves to before last.

Specified by:

beforeLast in interface ResultsetRows

moveRowRelative

public void moveRowRelative(int rows)

Description copied from interface: ResultsetRows

Moves the current position relative 'rows' from the current position.

Specified by:

moveRowRelative in interface ResultsetRows

Parameters:

rows - the relative number of rows to move

setCurrentRow

public void setCurrentRow(int rowNumber)

Description copied from interface: ResultsetRows

Moves the current position in the result set to the given row number.

Specified by:

setCurrentRow in interface ResultsetRows

Parameters:

rowNumber - row to move to