org.apache.directory.mavibot.btree

Interface Cursor<K>

Type Parameters:

K - The type for the Key

All Known Subinterfaces:

ValueCursor<V>

All Known Implementing Classes:

EmptyValueCursor, ValueArrayCursor, ValueBTreeCursor

public interface Cursor<K>

A Cursor is used to fetch elements in a BTree and is returned by the

See Also:

method. The cursor must be closed when the user is done with it.

Field Summary

Fields

Modifier and Type	Field and Description
static int	AFTER_LAST
static int	BEFORE_FIRST Static value for the beforeFrst and afterLast positions

Method Summary

Modifier and Type	Method and Description
void	afterLast() Places the cursor at the end of the last position
void	beforeFirst() moves the cursor to the same position that was given at the time of instantiating the cursor.
void	close() Closes the cursor, thus releases the associated transaction
boolean	hasNext() Tells if the cursor can return a next element
boolean	hasPrev() Tells if the cursor can return a previous element

Field Detail

BEFORE_FIRST

static final int BEFORE_FIRST

Static value for the beforeFrst and afterLast positions

See Also:

Constant Field Values

AFTER_LAST

static final int AFTER_LAST

See Also:

Constant Field Values

Method Detail

hasNext

boolean hasNext()
         throws EndOfFileExceededException,
                java.io.IOException

Tells if the cursor can return a next element

Returns:

true if there are some more elements

Throws:

java.io.IOException

EndOfFileExceededException

hasPrev

boolean hasPrev()
         throws EndOfFileExceededException,
                java.io.IOException

Tells if the cursor can return a previous element

Returns:

true if there are some more elements

Throws:

java.io.IOException

EndOfFileExceededException

close

void close()

Closes the cursor, thus releases the associated transaction

beforeFirst

void beforeFirst()
          throws java.io.IOException

moves the cursor to the same position that was given at the time of instantiating the cursor. For example, if the cursor was created using browse() method, then beforeFirst() will place the cursor before the 0th position. If the cursor was created using browseFrom(K), then calling beforeFirst() will reset the position to the just before the position where K is present.

Throws:

java.io.IOException

afterLast

void afterLast()
        throws java.io.IOException

Places the cursor at the end of the last position

Throws:

java.io.IOException