net.rim.device.api.database
Class BufferedCursor
java.lang.Object
net.rim.device.api.database.BufferedCursor
- All Implemented Interfaces:
- Cursor
public class BufferedCursor
- extends Object
- implements Cursor
Caches all rows in memory for bidirectional or random access. Suitable for
small cursors that provide forward-only data access.
Note that using the buffered cursor may throw an OutOfMemoryError if
it is used with huge data queries.
- Category:
- Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
- Since:
- BlackBerry API 5.0.0
|
Method Summary |
|
void |
close()
Closes cursor object, releasing all of its resources and making it
completely invalid. |
|
boolean |
first()
Navigates to the first row |
|
int |
getColumnIndex(String columnName)
Returns the zero-based index for a given column name. |
|
String |
getColumnName(int columnIndex)
Returns the column name at a given zero-based column index. |
|
int |
getPosition()
Returns the current Cursor position. |
|
Row |
getRow()
Retrieves current row with values. |
|
boolean |
isEmpty()
Determines if the cursor contains rows. |
|
boolean |
last()
Move the cursor to the last row. |
|
boolean |
next()
Moves the cursor to the next row. |
|
boolean |
position(int row)
Positiones cursor on the specified position |
|
boolean |
prev()
Navigates to the previous row if it exists |
BufferedCursor
public BufferedCursor(Cursor cursor)
throws NullPointerException
- Creates buffered cursor based on given delegate
- Throws:
NullPointerException - if the cursor parameter is NULL- Category:
- Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
- Since:
- BlackBerry API 5.0.0
first
public boolean first()
throws DatabaseException
- Navigates to the first row
- Specified by:
first in interface Cursor
- Returns:
- true if there is at least one row in the cursor, false if the
cursor is empty
- Throws:
DatabaseException - if the first row can not be retrieved from database or if
current position is after the first row in the forward
only type cursor.- Category:
- Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
- Since:
- BlackBerry API 5.0.0
getPosition
public int getPosition()
throws DatabaseException
- Description copied from interface:
Cursor
- Returns the current Cursor position.
If cursor was not navigated through Cursor.next(), Cursor.last() and
similar methods then its current position is before the first row and
marked as -1.
- Specified by:
getPosition in interface Cursor
- Returns:
- current Cursor position or -1 when cursor contains no rows or was
never navigated.
- Throws:
DatabaseException- See Also:
Cursor.getPosition()- Category:
- Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
- Since:
- BlackBerry API 5.0.0
getRow
public Row getRow()
throws DatabaseException
- Description copied from interface:
Cursor
- Retrieves current row with values.
Cursor must be positioned on a row for this method to return non-null
value. When the cursor is opened it is positioned before the first row
and this method will return NULL. Call Cursor.first() or
Cursor.next() to navigate to the first row and then call getRow() to
get the data.
- Specified by:
getRow in interface Cursor
- Returns:
- Row Current row or NULL if cursor contains no rows or is not
positioned on a row.
- Throws:
DatabaseException- See Also:
Cursor.getRow()- Category:
- Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
- Since:
- BlackBerry API 5.0.0
last
public boolean last()
throws DatabaseException
- Description copied from interface:
Cursor
- Move the cursor to the last row.
The method would return false if the cursor is empty.
- Specified by:
last in interface Cursor
- Returns:
- whether the move succeeded.
- Throws:
DatabaseException - if the last row can not be retrieved from the database.- See Also:
Cursor.last()- Category:
- Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
- Since:
- BlackBerry API 5.0.0
next
public boolean next()
throws DatabaseException
- Description copied from interface:
Cursor
- Moves the cursor to the next row.
Calling next() method the first time will position cursor on the first
row if it is available. Similarly, if cursor is positioned on the last
row then calling next() will move the pointer after the last row and row
data access methods would return invalid data.
- Specified by:
next in interface Cursor
- Returns:
- whether the move succeeded.
- Throws:
DatabaseException- See Also:
Cursor.next()- Category:
- Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
- Since:
- BlackBerry API 5.0.0
position
public boolean position(int row)
throws DatabaseException
- Positiones cursor on the specified position
- Specified by:
position in interface Cursor
- Parameters:
row - zero-based position to move to.
- Returns:
- whether the requested move fully succeeded.
- Throws:
DatabaseException- Category:
- Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
- Since:
- BlackBerry API 5.0.0
prev
public boolean prev()
throws DatabaseException
- Navigates to the previous row if it exists
- Specified by:
prev in interface Cursor
- Returns:
- true if there is a previous row, false otherwise
- Throws:
DatabaseException- Category:
- Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
- Since:
- BlackBerry API 5.0.0
close
public void close()
throws DatabaseException
- Description copied from interface:
Cursor
- Closes cursor object, releasing all of its resources and making it
completely invalid.
- Specified by:
close in interface Cursor
- Throws:
DatabaseException- See Also:
Cursor.close()- Category:
- Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
- Since:
- BlackBerry API 5.0.0
isEmpty
public boolean isEmpty()
throws DatabaseException
- Description copied from interface:
Cursor
- Determines if the cursor contains rows.
Note that information whether the cursor is empty or not is available
only after navigating to a row through any of the following methods
Cursor.first(), Cursor.next(), Cursor.last(). If the cursor was
never navigated then this method returns true meaning that
no rows were fetched.
- Specified by:
isEmpty in interface Cursor
- Returns:
- true if cursor contains at least one row, false otherwise.
- Throws:
DatabaseException - if database communication is broken.- See Also:
Cursor.isEmpty()- Category:
- Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
- Since:
- BlackBerry API 5.0.0
getColumnIndex
public int getColumnIndex(String columnName)
throws DatabaseException
- Description copied from interface:
Cursor
- Returns the zero-based index for a given column name.
Note that columns meta information is available only after navigation to
the first row. Call Cursor.next() or Cursor.first() before calling
this method.
- Specified by:
getColumnIndex in interface Cursor
- Parameters:
columnName - the name of the target column.
- Returns:
- Returns the zero-based column index for the given column name;
or -1 if the column name does not exist.
- Throws:
DatabaseException - if cursor is closed- See Also:
Cursor.getColumnIndex(String)- Category:
- Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
- Since:
- BlackBerry API 5.0.0
getColumnName
public String getColumnName(int columnIndex)
throws DatabaseException
- Description copied from interface:
Cursor
- Returns the column name at a given zero-based column index.
Note that columns meta information is available only after navigation to
the first row. Call Cursor.next() or Cursor.first() before calling
this method.
- Specified by:
getColumnName in interface Cursor
- Parameters:
columnIndex - the zero-based index of the target column.
- Returns:
- the column name for the given column index; or
null if the given column index is larger than the number of columns.
- Throws:
DatabaseException - if cursor is closed- See Also:
Cursor.getColumnName(int)- Category:
- Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
- Since:
- BlackBerry API 5.0.0
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