public class DifferenceEnumeration extends java.lang.Object implements SequenceIterator
|Constructor and Description|
Form an enumeration of the difference of two nodesets, that is, the nodes that are in p1 and that are not in p2.
|Modifier and Type||Method and Description|
Close the iterator.
Calling this method instructs the iterator to release any resources it holds, while still remaining able to deliver the remaining items in the sequence.
Get the next item in the sequence.
public DifferenceEnumeration(SequenceIterator p1, SequenceIterator p2, java.util.Comparator<? super NodeInfo> comparer) throws XPathException
p1- the first operand, with nodes delivered in document order
p2- the second operand, with nodes delivered in document order
comparer- the comparer
XPathException- if a failure occurs reading from either input sequence
public NodeInfo next()
public void close()
For example, the iterator returned by the unparsed-text-lines() function has a close() method that causes the underlying input stream to be closed, whether or not the file has been read to completion.
Closing an iterator is important when the data is being "pushed" in another thread. Closing the iterator terminates that thread and means that it needs to do no additional work. Indeed, failing to close the iterator may cause the push thread to hang waiting for the buffer to be emptied.
Closing an iterator is not necessary if the iterator is read to completion: if a call
SequenceIterator.next() returns null, the iterator will be closed automatically. An explicit
SequenceIterator.close() is needed only when iteration is abandoned prematurely.
public void discharge()
SequenceIterator.close()will be called when no more items are needed.
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