Package com.coyotegulch.jisp

Interface IndexIterator

All Known Implementing Classes:

BTreeIterator

public interface IndexIterator

IndexIterator defines an object that references a specific object relative to other objects in an ObjectIndex.

See Also:

ObjectIndex, BTreeIndex, BTreeIterator, IndexedObjectDatabase

Method Summary

Modifier and Type	Method	Description
java.lang.Object	getKey()	Returns the key Object currently referenced by this iterator.
long	getRecPtr()	Returns the record Object currently referenced by this iterator.
boolean	isValid()	Checks to see if this iterator is valid.
boolean	moveFirst()	Moves this iterator to the first record in sequence.
boolean	moveLast()	Moves this iterator to the last record in sequence.
boolean	moveNext()	Moves this iterator to the next record in sequence.
boolean	movePrevious()	Moves this iterator to the previous record in sequence.
boolean	moveTo(KeyObject key)	Moves this iterator to the record associated with the given key.
boolean	moveTo(KeyObject key, boolean acceptNext)	Moves this iterator to the record associated with the given key.

Method Detail

getRecPtr

long getRecPtr()
        throws java.io.IOException

Returns the record Object currently referenced by this iterator.

Returns:

a long pointer (usually a file position) associated with this index entry; returns -1 if the iterator is invalid or the record was not found

Throws:

java.io.IOException

getKey

java.lang.Object getKey()
                 throws java.io.IOException

Returns the key Object currently referenced by this iterator.

Returns:

the key Object currently referenced by this iterator; returns null if the iterator is invalid or the record was not found

Throws:

java.io.IOException

moveNext

boolean moveNext()
          throws java.io.IOException,
                 java.lang.ClassNotFoundException

Moves this iterator to the next record in sequence.

Returns:

true if the operation was successful; false otherwise

Throws:

java.io.IOException

java.lang.ClassNotFoundException

movePrevious

boolean movePrevious()
              throws java.io.IOException,
                     java.lang.ClassNotFoundException

Moves this iterator to the previous record in sequence.

Returns:

true if the operation was successful; false otherwise.

Throws:

java.io.IOException

java.lang.ClassNotFoundException

moveFirst

boolean moveFirst()
           throws java.io.IOException,
                  java.lang.ClassNotFoundException

Moves this iterator to the first record in sequence.

Returns:

true if the operation was successful; false otherwise.

Throws:

java.io.IOException

java.lang.ClassNotFoundException

moveLast

boolean moveLast()
          throws java.io.IOException,
                 java.lang.ClassNotFoundException

Moves this iterator to the last record in sequence.

Returns:

true if the operation was successful; false otherwise.

Throws:

java.io.IOException

java.lang.ClassNotFoundException

moveTo

boolean moveTo(KeyObject key)
        throws java.io.IOException,
               java.lang.ClassNotFoundException

Moves this iterator to the record associated with the given key.

Parameters:

key - key identifier to find

Returns:

true if the operation was successful; false otherwise.

Throws:

java.io.IOException

java.lang.ClassNotFoundException

moveTo

boolean moveTo(KeyObject key,
               boolean acceptNext)
        throws java.io.IOException,
               java.lang.ClassNotFoundException

Moves this iterator to the record associated with the given key.

Parameters:

key - key identifier to find

Returns:

true if the operation was successful; false otherwise.

Throws:

java.io.IOException

java.lang.ClassNotFoundException

isValid

boolean isValid()

Checks to see if this iterator is valid.

Returns:

true if the iterator is valid; false if it is invalid.