Class TextLinesIterator

java.lang.Object
net.sf.saxon.tree.iter.TextLinesIterator
All Implemented Interfaces:
Closeable, AutoCloseable, SequenceIterator
Direct Known Subclasses:
UnparsedTextIterator

public abstract class TextLinesIterator extends Object implements SequenceIterator
An iterator that iterates over a file line by line, returning each line as a StringValue
  • Field Details

  • Constructor Details

    • TextLinesIterator

      protected TextLinesIterator()
    • TextLinesIterator

      public TextLinesIterator(LineNumberReader reader, Location location, URI uri, IntPredicateProxy checker) throws XPathException
      Create a TextLinesIterator over a given reader
      Parameters:
      reader - the reader that reads the file
      location - the location of the instruction being executed, for diagnostics. May be null.
      uri - the URI of the file being read, for diagnostics
      checker - checks that the characters in the file are legal XML characters
      Throws:
      XPathException - if a dynamic error occurs
  • Method Details

    • next

      public StringValue next()
      Description copied from interface: SequenceIterator
      Get the next item in the sequence. This method changes the state of the iterator.
      Specified by:
      next in interface SequenceIterator
      Returns:
      the next item, or null if there are no more items. Once a call on next() has returned null, no further calls should be made. The preferred action for an iterator if subsequent calls on next() are made is to return null again, and all implementations within Saxon follow this rule.
    • handleIOError

      protected XPathException handleIOError(URI uri, IOException err)
    • close

      public void close()
      Description copied from interface: SequenceIterator
      Close the iterator. This indicates to the supplier of the data that the client does not require any more items to be delivered by the iterator. This may enable the supplier to release resources. After calling close(), no further calls on the iterator should be made; if further calls are made, the effect of such calls is undefined.

      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 on SequenceIterator.next() returns null, the iterator will be closed automatically. An explicit call on SequenceIterator.close() is needed only when iteration is abandoned prematurely.

      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in interface SequenceIterator
    • discharge

      public void discharge()
      Description copied from interface: SequenceIterator
      Calling this method instructs the iterator to release any resources it holds, while still remaining able to deliver the remaining items in the sequence. This may require the iterator to calculate the rest of the sequence eagerly. The method is called by a client if it anticipates that it might not read the iterator to completion, but it cannot guarantee that SequenceIterator.close() will be called when no more items are needed.
      Specified by:
      discharge in interface SequenceIterator