org.exist.storage.dom
Class NodeIterator

java.lang.Object
  org.exist.storage.dom.NodeIterator

All Implemented Interfaces:

java.util.Iterator

public final class NodeIterator

extends java.lang.Object

implements java.util.Iterator

Class NodeIterator is used to iterate over nodes in the DOM storage. This implementation locks the DOM file to read the node and unlocks it afterwards. It is thus safer than DOMFileIterator, since the node's value will not change.

Author:

wolf

Constructor Summary

NodeIterator(java.lang.Object lock, DOMFile db, DocumentImpl doc, long address)

NodeIterator(java.lang.Object lock, DOMFile db, NodeProxy node, boolean poolable)

Method Summary

long	currentAddress() Returns the internal virtual address of the node at the iterator's current position.
boolean	hasNext() Are there more nodes to be read?
java.lang.Object	next() Returns the next node in document order.
void	remove() Remove the current node.
void	setTo(long address) Reposition the iterate at a given address.
void	setTo(NodeProxy node) Reposition the iterator at the address of the proxy node.

Methods inherited from class java.lang.Object

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

Constructor Detail

NodeIterator

public NodeIterator(java.lang.Object lock,
                    DOMFile db,
                    NodeProxy node,
                    boolean poolable)
             throws BTreeException,
                    java.io.IOException

NodeIterator

public NodeIterator(java.lang.Object lock,
                    DOMFile db,
                    DocumentImpl doc,
                    long address)

Method Detail

currentAddress

public long currentAddress()

Returns the internal virtual address of the node at the iterator's current position.

Returns:

The currentAddress value

hasNext

public boolean hasNext()

Are there more nodes to be read?

Specified by:

hasNext in interface java.util.Iterator

Returns:

Description of the Return Value

next

public java.lang.Object next()

Returns the next node in document order.

Specified by:

next in interface java.util.Iterator

remove

public void remove()

Remove the current node. This implementation just decrements the node count. It does not actually remove the node's value, but removes a page if node count == 0. Use this method only if you want to delete an entire document, not to remove a single node.

Specified by:

remove in interface java.util.Iterator

setTo

public void setTo(NodeProxy node)

Reposition the iterator at the address of the proxy node.

Parameters:

node - The new to value

setTo

public void setTo(long address)

Reposition the iterate at a given address.

Parameters:

address - The new to value