/**
* The contents of this file are subject to the Mozilla Public License Version 1.1
* (the "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at http://www.mozilla.org/MPL/
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the
* specific language governing rights and limitations under the License.
*
* The Original Code is "ReadOnlyMessageIterator.java". Description:
* "Iterator though existing Stuctures in a message. "
*
* The Initial Developer of the Original Code is University Health Network. Copyright (C)
* 2005. All Rights Reserved.
*
* Contributor(s): ______________________________________.
*
* Alternatively, the contents of this file may be used under the terms of the
* GNU General Public License (the �GPL�), in which case the provisions of the GPL are
* applicable instead of those above. If you wish to allow use of your version of this
* file only under the terms of the GPL and not to allow others to use your version
* of this file under the MPL, indicate your decision by deleting the provisions above
* and replace them with the notice and other provisions required by the GPL License.
* If you do not delete the provisions above, a recipient may use your version of
* this file under either the MPL or the GPL.
*
*/
package ca.uhn.hl7v2.util;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import ca.uhn.hl7v2.HL7Exception;
import ca.uhn.hl7v2.model.Group;
import ca.uhn.hl7v2.model.Segment;
import ca.uhn.hl7v2.model.Structure;
import ca.uhn.hl7v2.parser.EncodingCharacters;
import ca.uhn.hl7v2.parser.PipeParser;
/**
* Iterator though existing Stuctures in a message. No new repetitions or optional
* structures are created during iteration (in contrast to MessageIterator).
*
* Note that some structures are created during parsing, so the iteration may include
* structures which were not present in the original encoded message. If these are
* not desired they can be skipped using a FilterIterator. In fact to obtain an
* iterator only over populated segments (not groups or empty segments) use the factory
* method in this class.
*
* @author <a href="mailto:bryan.tripp@uhn.on.ca">Bryan Tripp</a>
* @version $Revision: 1.1 $ updated on $Date: 2007/02/19 02:24:27 $ by $Author: jamesagnew $
*/
public class ReadOnlyMessageIterator implements Iterator {
private List myRemaining; //remaining nodes in reverse order (i.e. last is next)
/**
* @param theRoot root of depth first iteration, which starts with the first child
*/
public ReadOnlyMessageIterator(Group theRoot) {
myRemaining = new ArrayList(40);
addChildren(theRoot);
}
/**
* @param theRoot root of depth first iteration, which starts with the first child
* @return an iterator that skips groups and empty segments, returning only populated
* segments
*/
public static Iterator createPopulatedSegmentIterator(Group theRoot) {
Iterator allIterator = new ReadOnlyMessageIterator(theRoot);
FilterIterator.Predicate segmentsOnly = new FilterIterator.Predicate() {
public boolean evaluate(Object obj) {
if (Segment.class.isAssignableFrom(obj.getClass())) {
return true;
} else {
return false;
}
}
};
FilterIterator segmentIterator = new FilterIterator(allIterator, segmentsOnly);
final EncodingCharacters ec = new EncodingCharacters('|', "^~\\&");
FilterIterator.Predicate populatedOnly = new FilterIterator.Predicate() {
public boolean evaluate(Object obj) {
String encoded = PipeParser.encode((Segment) obj, ec);
if (encoded.length() > 3) {
return true;
} else {
return false;
}
}
};
return new FilterIterator(segmentIterator, populatedOnly);
}
private void addChildren(Group theParent) {
String[] names = theParent.getNames();
for (int i = names.length - 1; i >= 0; i--) {
try {
Structure[] reps = theParent.getAll(names[i]);
for (int j = reps.length - 1; j >= 0; j--) {
myRemaining.add(reps[j]);
}
} catch (HL7Exception e) {
throw new Error("Internal error: an invalid child name was obtained from its parent.");
}
}
}
/**
* @see java.util.Iterator#hasNext()
*/
public boolean hasNext() {
return !myRemaining.isEmpty();
}
/**
* @see java.util.Iterator#next()
*/
public Object next() {
if (!hasNext()) {
throw new NoSuchElementException("No more nodes in message");
}
Structure next = (Structure) myRemaining.remove(myRemaining.size() - 1);
if (next instanceof Group) {
addChildren((Group) next);
}
return next;
}
/**
* Not supported.
*/
public void remove() {
throw new UnsupportedOperationException("Can't remove a node from a message");
}
}