com.healthmarketscience.jackcess.impl

Class CursorImpl

java.lang.Object

com.healthmarketscience.jackcess.impl.CursorImpl

All Implemented Interfaces:

Cursor, Iterable<Row>

Direct Known Subclasses:

IndexCursorImpl, TableScanCursor

public abstract class CursorImpl
extends Object
implements Cursor

Manages iteration for a Table. Different cursors provide different methods of traversing a table. Cursors should be fairly robust in the face of table modification during traversal (although depending on how the table is traversed, row updates may or may not be seen). Multiple cursors may traverse the same table simultaneously.

The Cursor provides a variety of static utility methods to construct cursors with given characteristics or easily search for specific values. For even friendlier and more flexible construction, see CursorBuilder.

Is not thread-safe.

Author:

James Ahlborn

Nested Class Summary

Nested classes/interfaces inherited from interface com.healthmarketscience.jackcess.Cursor

Cursor.Id, Cursor.Position, Cursor.Savepoint

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	MOVE_FORWARD boolean value indicating forward movement
static boolean	MOVE_REVERSE boolean value indicating reverse movement

Method Summary

Modifier and Type	Method and Description
void	afterLast() Resets this cursor for reverse traversal (sets cursor to after the last row).
void	beforeFirst() Resets this cursor for forward traversal (sets cursor to before the first row).
static CursorImpl	createCursor(TableImpl table) Creates a normal, un-indexed cursor for the given table.
boolean	currentRowMatches(ColumnImpl columnPattern, Object valuePattern)
boolean	currentRowMatches(Column columnPattern, Object valuePattern) Returns true if the current row matches the given pattern.
boolean	currentRowMatches(Map<String,?> rowPattern) Returns true if the current row matches the given pattern.
void	deleteCurrentRow() Delete the current row.
boolean	findFirstRow(ColumnImpl columnPattern, Object valuePattern)
boolean	findFirstRow(Column columnPattern, Object valuePattern) Moves to the first row (as defined by the cursor) where the given column has the given value.
boolean	findFirstRow(Map<String,?> rowPattern) Moves to the first row (as defined by the cursor) where the given columns have the given values.
boolean	findNextRow(ColumnImpl columnPattern, Object valuePattern)
boolean	findNextRow(Column columnPattern, Object valuePattern) Moves to the next row (as defined by the cursor) where the given column has the given value.
boolean	findNextRow(Map<String,?> rowPattern) Moves to the next row (as defined by the cursor) where the given columns have the given values.
boolean	findRow(RowId rowId) Moves to the row with the given rowId.
ColumnMatcher	getColumnMatcher() Returns the currently configured ColumnMatcher, always non-null.
Row	getCurrentRow() Returns the current row in this cursor (Column name -> Column value).
Row	getCurrentRow(Collection<String> columnNames) Returns the current row in this cursor (Column name -> Column value).
Object	getCurrentRowValue(Column column) Returns the given column from the current row.
Object	getCurrentRowValue(ColumnImpl column)
ErrorHandler	getErrorHandler() Gets the currently configured ErrorHandler (always non-null).
JetFormat	getFormat()
com.healthmarketscience.jackcess.impl.CursorImpl.IdImpl	getId()
Row	getNextRow() Moves to the next row in the table and returns it.
Row	getNextRow(Collection<String> columnNames) Moves to the next row in the table and returns it.
PageChannel	getPageChannel()
Row	getPreviousRow() Moves to the previous row in the table and returns it.
Row	getPreviousRow(Collection<String> columnNames) Moves to the previous row in the table and returns it.
TableImpl.RowState	getRowState()
com.healthmarketscience.jackcess.impl.CursorImpl.SavepointImpl	getSavepoint() Returns the current state of the cursor which can be restored at a future point in time by a call to Cursor.restoreSavepoint(com.healthmarketscience.jackcess.Cursor.Savepoint).
TableImpl	getTable()
boolean	isAfterLast() Returns true if the cursor is currently positioned after the last row, false otherwise.
boolean	isBeforeFirst() Returns true if the cursor is currently positioned before the first row, false otherwise.
boolean	isCurrentRowDeleted() Returns true if the row at which the cursor is currently positioned is deleted, false otherwise (including invalid rows).
Iterator<Row>	iterator() Calls Cursor.beforeFirst() on this cursor and returns a modifiable Iterator which will iterate through all the rows of this table.
Iterator<Row>	iterator(IterableBuilder iterBuilder)
int	moveNextRows(int numRows) Moves forward as many rows as possible up to the given number of rows.
int	movePreviousRows(int numRows) Moves backward as many rows as possible up to the given number of rows.
boolean	moveToNextRow() Moves to the next row as defined by this cursor.
boolean	moveToPreviousRow() Moves to the previous row as defined by this cursor.
IterableBuilder	newIterable() Convenience method for constructing a new IterableBuilder for this cursor.
void	reset() Resets this cursor for forward traversal.
void	restoreSavepoint(Cursor.Savepoint savepoint) Moves the cursor to a savepoint previously returned from Cursor.getSavepoint().
void	restoreSavepoint(com.healthmarketscience.jackcess.impl.CursorImpl.SavepointImpl savepoint)
void	setColumnMatcher(ColumnMatcher columnMatcher) Sets a new ColumnMatcher.
void	setCurrentRowValue(ColumnImpl column, Object value)
void	setCurrentRowValue(Column column, Object value) Updates a single value in the current row.
void	setErrorHandler(ErrorHandler newErrorHandler) Sets a new ErrorHandler.
String	toString()
Object[]	updateCurrentRow(Object... row) Update the current row.
<M extends Map<String,Object>> M	updateCurrentRowFromMap(M row) Update the current row.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.healthmarketscience.jackcess.Cursor

stream

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

MOVE_FORWARD

public static final boolean MOVE_FORWARD

boolean value indicating forward movement

See Also:

Constant Field Values

MOVE_REVERSE

public static final boolean MOVE_REVERSE

boolean value indicating reverse movement

See Also:

Constant Field Values

Method Detail

createCursor

public static CursorImpl createCursor(TableImpl table)

Creates a normal, un-indexed cursor for the given table.

Parameters:

table - the table over which this cursor will traverse

getRowState

public TableImpl.RowState getRowState()

getId

public com.healthmarketscience.jackcess.impl.CursorImpl.IdImpl getId()

Specified by:

getId in interface Cursor

getTable

public TableImpl getTable()

Specified by:

getTable in interface Cursor

getFormat

public JetFormat getFormat()

getPageChannel

public PageChannel getPageChannel()

getErrorHandler

public ErrorHandler getErrorHandler()

Description copied from interface: Cursor

Gets the currently configured ErrorHandler (always non-null). This will be used to handle all errors.

Specified by:

getErrorHandler in interface Cursor

setErrorHandler

public void setErrorHandler(ErrorHandler newErrorHandler)

Description copied from interface: Cursor

Sets a new ErrorHandler. If null, resets to using the ErrorHandler configured at the Table level.

Specified by:

setErrorHandler in interface Cursor

getColumnMatcher

public ColumnMatcher getColumnMatcher()

Description copied from interface: Cursor

Returns the currently configured ColumnMatcher, always non-null.

Specified by:

getColumnMatcher in interface Cursor

setColumnMatcher

public void setColumnMatcher(ColumnMatcher columnMatcher)

Description copied from interface: Cursor

Sets a new ColumnMatcher. If null, resets to using the default matcher (default depends on Cursor type).

Specified by:

setColumnMatcher in interface Cursor

getSavepoint

public com.healthmarketscience.jackcess.impl.CursorImpl.SavepointImpl getSavepoint()

Description copied from interface: Cursor

Returns the current state of the cursor which can be restored at a future point in time by a call to Cursor.restoreSavepoint(com.healthmarketscience.jackcess.Cursor.Savepoint).

Savepoints may be used across different cursor instances for the same table, but they must have the same Cursor.Id.

Specified by:

getSavepoint in interface Cursor

restoreSavepoint

public void restoreSavepoint(Cursor.Savepoint savepoint)
                      throws IOException

Description copied from interface: Cursor

Moves the cursor to a savepoint previously returned from Cursor.getSavepoint().

Specified by:

restoreSavepoint in interface Cursor

Throws:

IOException

restoreSavepoint

public void restoreSavepoint(com.healthmarketscience.jackcess.impl.CursorImpl.SavepointImpl savepoint)
                      throws IOException

Throws:

IOException

reset

public void reset()

Description copied from interface: Cursor

Resets this cursor for forward traversal. Calls Cursor.beforeFirst().

Specified by:

reset in interface Cursor

beforeFirst

public void beforeFirst()

Description copied from interface: Cursor

Resets this cursor for forward traversal (sets cursor to before the first row).

Specified by:

beforeFirst in interface Cursor

afterLast

public void afterLast()

Description copied from interface: Cursor

Resets this cursor for reverse traversal (sets cursor to after the last row).

Specified by:

afterLast in interface Cursor

isBeforeFirst

public boolean isBeforeFirst()
                      throws IOException

Description copied from interface: Cursor

Returns true if the cursor is currently positioned before the first row, false otherwise.

Specified by:

isBeforeFirst in interface Cursor

Throws:

IOException

isAfterLast

public boolean isAfterLast()
                    throws IOException

Description copied from interface: Cursor

Returns true if the cursor is currently positioned after the last row, false otherwise.

Specified by:

isAfterLast in interface Cursor

Throws:

IOException

isCurrentRowDeleted

public boolean isCurrentRowDeleted()
                            throws IOException

Description copied from interface: Cursor

Returns true if the row at which the cursor is currently positioned is deleted, false otherwise (including invalid rows).

Specified by:

isCurrentRowDeleted in interface Cursor

Throws:

IOException

iterator

public Iterator<Row> iterator()

Description copied from interface: Cursor

Calls Cursor.beforeFirst() on this cursor and returns a modifiable Iterator which will iterate through all the rows of this table. Use of the Iterator follows the same restrictions as a call to Cursor.getNextRow().

For more flexible iteration see Cursor.newIterable().

Specified by:

iterator in interface Cursor

Specified by:

iterator in interface Iterable<Row>

newIterable

public IterableBuilder newIterable()

Description copied from interface: Cursor

Convenience method for constructing a new IterableBuilder for this cursor. An IterableBuilder provides a variety of options for more flexible iteration.

Specified by:

newIterable in interface Cursor

iterator

public Iterator<Row> iterator(IterableBuilder iterBuilder)

deleteCurrentRow

public void deleteCurrentRow()
                      throws IOException

Description copied from interface: Cursor

Delete the current row.

Note, re-deleting an already deleted row is allowed (it does nothing).

Specified by:

deleteCurrentRow in interface Cursor

Throws:

IOException

updateCurrentRow

public Object[] updateCurrentRow(Object... row)
                          throws IOException

Description copied from interface: Cursor

Update the current row.

Specified by:

updateCurrentRow in interface Cursor

Returns:

the given row values if long enough, otherwise a new array, updated with the current row values

Throws:

IOException

updateCurrentRowFromMap

public <M extends Map<String,Object>> M updateCurrentRowFromMap(M row)
                                                         throws IOException

Description copied from interface: Cursor

Update the current row.

Specified by:

updateCurrentRowFromMap in interface Cursor

Returns:

the given row, updated with the current row values

Throws:

IOException

getNextRow

public Row getNextRow()
               throws IOException

Description copied from interface: Cursor

Moves to the next row in the table and returns it.

Specified by:

getNextRow in interface Cursor

Returns:

The next row in this table (Column name -> Column value), or null if no next row is found

Throws:

IOException

getNextRow

public Row getNextRow(Collection<String> columnNames)
               throws IOException

Description copied from interface: Cursor

Moves to the next row in the table and returns it.

Specified by:

getNextRow in interface Cursor

Parameters:

columnNames - Only column names in this collection will be returned

Returns:

The next row in this table (Column name -> Column value), or null if no next row is found

Throws:

IOException

getPreviousRow

public Row getPreviousRow()
                   throws IOException

Description copied from interface: Cursor

Moves to the previous row in the table and returns it.

Specified by:

getPreviousRow in interface Cursor

Returns:

The previous row in this table (Column name -> Column value), or null if no previous row is found

Throws:

IOException

getPreviousRow

public Row getPreviousRow(Collection<String> columnNames)
                   throws IOException

Description copied from interface: Cursor

Moves to the previous row in the table and returns it.

Specified by:

getPreviousRow in interface Cursor

Parameters:

columnNames - Only column names in this collection will be returned

Returns:

The previous row in this table (Column name -> Column value), or null if no previous row is found

Throws:

IOException

moveToNextRow

public boolean moveToNextRow()
                      throws IOException

Description copied from interface: Cursor

Moves to the next row as defined by this cursor.

Specified by:

moveToNextRow in interface Cursor

Returns:

true if a valid next row was found, false otherwise

Throws:

IOException

moveToPreviousRow

public boolean moveToPreviousRow()
                          throws IOException

Description copied from interface: Cursor

Moves to the previous row as defined by this cursor.

Specified by:

moveToPreviousRow in interface Cursor

Returns:

true if a valid previous row was found, false otherwise

Throws:

IOException

findRow

public boolean findRow(RowId rowId)
                throws IOException

Description copied from interface: Cursor

Moves to the row with the given rowId. If the row is not found (or an exception is thrown), the cursor is restored to its previous state.

Specified by:

findRow in interface Cursor

Returns:

true if a valid row was found with the given id, false if no row was found

Throws:

IOException

findFirstRow

public boolean findFirstRow(Column columnPattern,
                            Object valuePattern)
                     throws IOException

Description copied from interface: Cursor

Moves to the first row (as defined by the cursor) where the given column has the given value. This may be more efficient on some cursors than others. If a match is not found (or an exception is thrown), the cursor is restored to its previous state.

Warning, this method always starts searching from the beginning of the Table (you cannot use it to find successive matches).

Specified by:

findFirstRow in interface Cursor

Parameters:

columnPattern - column from the table for this cursor which is being matched by the valuePattern

valuePattern - value which is equal to the corresponding value in the matched row. If this object is an instance of Predicate, it will be applied to the potential row value instead (overriding any configured ColumnMatcher)

Returns:

true if a valid row was found with the given value, false if no row was found

Throws:

IOException

findFirstRow

public boolean findFirstRow(ColumnImpl columnPattern,
                            Object valuePattern)
                     throws IOException

Throws:

IOException

findNextRow

public boolean findNextRow(Column columnPattern,
                           Object valuePattern)
                    throws IOException

Description copied from interface: Cursor

Moves to the next row (as defined by the cursor) where the given column has the given value. This may be more efficient on some cursors than others. If a match is not found (or an exception is thrown), the cursor is restored to its previous state.

Specified by:

findNextRow in interface Cursor

Parameters:

columnPattern - column from the table for this cursor which is being matched by the valuePattern

valuePattern - value which is equal to the corresponding value in the matched row. If this object is an instance of Predicate, it will be applied to the potential row value instead (overriding any configured ColumnMatcher)

Returns:

true if a valid row was found with the given value, false if no row was found

Throws:

IOException

findNextRow

public boolean findNextRow(ColumnImpl columnPattern,
                           Object valuePattern)
                    throws IOException

Throws:

IOException

findFirstRow

public boolean findFirstRow(Map<String,?> rowPattern)
                     throws IOException

Description copied from interface: Cursor

Moves to the first row (as defined by the cursor) where the given columns have the given values. This may be more efficient on some cursors than others. If a match is not found (or an exception is thrown), the cursor is restored to its previous state.

Warning, this method always starts searching from the beginning of the Table (you cannot use it to find successive matches).

Specified by:

findFirstRow in interface Cursor

Parameters:

rowPattern - column names and values which must be equal to the corresponding values in the matched row. If a value is an instance of Predicate, it will be applied to the potential row value instead (overriding any configured ColumnMatcher)

Returns:

true if a valid row was found with the given values, false if no row was found

Throws:

IOException

findNextRow

public boolean findNextRow(Map<String,?> rowPattern)
                    throws IOException

Description copied from interface: Cursor

Moves to the next row (as defined by the cursor) where the given columns have the given values. This may be more efficient on some cursors than others. If a match is not found (or an exception is thrown), the cursor is restored to its previous state.

Specified by:

findNextRow in interface Cursor

Parameters:

rowPattern - column names and values which must be equal to the corresponding values in the matched row. If a value is an instance of Predicate, it will be applied to the potential row value instead (overriding any configured ColumnMatcher)

Returns:

true if a valid row was found with the given values, false if no row was found

Throws:

IOException

currentRowMatches

public boolean currentRowMatches(Column columnPattern,
                                 Object valuePattern)
                          throws IOException

Description copied from interface: Cursor

Returns true if the current row matches the given pattern.

Specified by:

currentRowMatches in interface Cursor

Parameters:

columnPattern - column from the table for this cursor which is being matched by the valuePattern

valuePattern - value which is equal to the corresponding value in the matched row. If this object is an instance of Predicate, it will be applied to the potential row value instead (overriding any configured ColumnMatcher)

Throws:

IOException

currentRowMatches

public boolean currentRowMatches(ColumnImpl columnPattern,
                                 Object valuePattern)
                          throws IOException

Throws:

IOException

currentRowMatches

public boolean currentRowMatches(Map<String,?> rowPattern)
                          throws IOException

Description copied from interface: Cursor

Returns true if the current row matches the given pattern.

Specified by:

currentRowMatches in interface Cursor

Parameters:

rowPattern - column names and values which must be equal to the corresponding values in the matched row. If a value is an instance of Predicate, it will be applied to the potential row value instead (overriding any configured ColumnMatcher)

Throws:

IOException

moveNextRows

public int moveNextRows(int numRows)
                 throws IOException

Description copied from interface: Cursor

Moves forward as many rows as possible up to the given number of rows.

Specified by:

moveNextRows in interface Cursor

Returns:

the number of rows moved.

Throws:

IOException

movePreviousRows

public int movePreviousRows(int numRows)
                     throws IOException

Description copied from interface: Cursor

Moves backward as many rows as possible up to the given number of rows.

Specified by:

movePreviousRows in interface Cursor

Returns:

the number of rows moved.

Throws:

IOException

getCurrentRow

public Row getCurrentRow()
                  throws IOException

Description copied from interface: Cursor

Returns the current row in this cursor (Column name -> Column value).

Specified by:

getCurrentRow in interface Cursor

Throws:

IOException

getCurrentRow

public Row getCurrentRow(Collection<String> columnNames)
                  throws IOException

Description copied from interface: Cursor

Returns the current row in this cursor (Column name -> Column value).

Specified by:

getCurrentRow in interface Cursor

Parameters:

columnNames - Only column names in this collection will be returned

Throws:

IOException

getCurrentRowValue

public Object getCurrentRowValue(Column column)
                          throws IOException

Description copied from interface: Cursor

Returns the given column from the current row.

Specified by:

getCurrentRowValue in interface Cursor

Throws:

IOException

getCurrentRowValue

public Object getCurrentRowValue(ColumnImpl column)
                          throws IOException

Throws:

IOException

setCurrentRowValue

public void setCurrentRowValue(Column column,
                               Object value)
                        throws IOException

Description copied from interface: Cursor

Updates a single value in the current row.

Specified by:

setCurrentRowValue in interface Cursor

Throws:

IOException

setCurrentRowValue

public void setCurrentRowValue(ColumnImpl column,
                               Object value)
                        throws IOException

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object