org.xmlunit.diff.DefaultNodeMatcher Maven / Gradle / Ivy
/*
This file is licensed to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
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http://www.apache.org/licenses/LICENSE-2.0
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distributed under the License is distributed on an "AS IS" BASIS,
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See the License for the specific language governing permissions and
limitations under the License.
*/
package org.xmlunit.diff;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.xmlunit.util.Linqy;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
/**
* Default implemetation of {@link NodeMatcher} that matches control
* and tests nodes for comparison with the help of {@link
* NodeTypeMatcher} and {@link ElementSelector}s.
*
* There is an important difference between using {@link
* ElementSelectors#or} to combine multiple {@link ElementSelector}s
* and using {@link DefaultNodeMatcher}'s constructor with multiple
* {@link ElementSelector}s:
*
* Consider {@link ElementSelector}s {@code e1} and {@code e2} and
* two control and test nodes each. Assume {@code e1} would match the
* first control node to the second test node and vice versa if used
* alone, while {@code e2} would match the nodes in order (the first
* control node to the first test and so on).
*
* {@link ElementSelectors#or} creates a combined {@link
* ElementSelector} that is willing to match the first control node to
* both of the test nodes - and the same for the second control node.
* Since nodes are compared in order when possible the result will be
* the same as running {@code e2} alone.
*
* {@link DefaultNodeMatcher} with two {@link ElementSelector}s
* will consult the {@link ElementSelector}s separately and only
* invoke {@code e2} if there are any nodes not matched by {@code e1}
* at all. In this case the result will be the same as running {@code
* e1} alone.
*/
public class DefaultNodeMatcher implements NodeMatcher {
private static final short TEXT = Node.TEXT_NODE;
private static final short CDATA = Node.CDATA_SECTION_NODE;
private final ElementSelector[] elementSelectors;
private final NodeTypeMatcher nodeTypeMatcher;
/**
* Creates a matcher using {@link ElementSelectors#Default} and
* {@link DefaultNodeTypeMatcher}.
*/
public DefaultNodeMatcher() {
this(ElementSelectors.Default);
}
/**
* Creates a matcher using the given {@link ElementSelector}s and
* {@link DefaultNodeTypeMatcher}.
*/
public DefaultNodeMatcher(ElementSelector... es) {
this(new DefaultNodeTypeMatcher(), es);
}
/**
* Creates a matcher using the given {@link ElementSelector}s and
* {@link NodeTypeMatcher}.
*
* The {@link ElementSelector}s are consulted in order so that
* the second {@link ElementSelector} only gets to match the nodes
* that the first one couldn't match to any test nodes ate all and
* so on.
*/
public DefaultNodeMatcher(NodeTypeMatcher ntm, ElementSelector... es) {
nodeTypeMatcher = ntm;
elementSelectors = es;
}
@Override
public Iterable> match(Iterable controlNodes,
Iterable testNodes) {
Map matches = new LinkedHashMap();
List controlList = Linqy.asList(controlNodes);
List testList = Linqy.asList(testNodes);
final int testSize = testList.size();
Set unmatchedTestIndexes = new HashSet();
for (int i = 0; i < testSize; i++) {
unmatchedTestIndexes.add(Integer.valueOf(i));
}
final int controlSize = controlList.size();
Match lastMatch = new Match(null, -1);
for (int i = 0; i < controlSize; i++) {
Node control = controlList.get(i);
Match testMatch = findMatchingNode(control, testList,
lastMatch.index,
unmatchedTestIndexes);
if (testMatch != null) {
unmatchedTestIndexes.remove(testMatch.index);
matches.put(control, testMatch.node);
}
}
return matches.entrySet();
}
private Match findMatchingNode(final Node searchFor,
final List searchIn,
final int indexOfLastMatch,
final Set availableIndexes) {
final int searchSize = searchIn.size();
Match m = searchIn(searchFor, searchIn,
availableIndexes,
indexOfLastMatch + 1, searchSize);
return m != null ? m : searchIn(searchFor, searchIn,
availableIndexes,
0, indexOfLastMatch);
}
private Match searchIn(final Node searchFor,
final List searchIn,
final Set availableIndexes,
final int fromInclusive, final int toExclusive) {
for (ElementSelector e : elementSelectors) {
Match m = searchIn(searchFor, searchIn, availableIndexes, fromInclusive, toExclusive, e);
if (m != null) {
return m;
}
}
return null;
}
private Match searchIn(final Node searchFor,
final List searchIn,
final Set availableIndexes,
final int fromInclusive, final int toExclusive,
final ElementSelector e) {
for (int i = fromInclusive; i < toExclusive; i++) {
if (!availableIndexes.contains(Integer.valueOf(i))) {
continue;
}
if (nodesMatch(searchFor, searchIn.get(i), e)) {
return new Match(searchIn.get(i), i);
}
}
return null;
}
private boolean nodesMatch(final Node n1, final Node n2,
final ElementSelector elementSelector) {
if (n1 instanceof Element && n2 instanceof Element) {
return elementSelector.canBeCompared((Element) n1, (Element) n2);
}
return nodeTypeMatcher.canBeCompared(n1.getNodeType(),
n2.getNodeType());
}
private static class Match {
private final Node node;
private final int index;
private Match(Node match, int index) {
this.node = match;
this.index = index;
}
}
/**
* Determines whether two Nodes are eligible for comparison based
* on their node type.
*/
public interface NodeTypeMatcher {
/**
* Determines whether two Nodes are eligible for comparison
* based on their node type.
*/
boolean canBeCompared(short controlType, short testType);
}
/**
* {@link NodeTypeMatcher} that marks pairs of nodes of the same
* node type as well as pairs of CDATA sections and text nodes as
* eligible.
*/
public static class DefaultNodeTypeMatcher implements NodeTypeMatcher {
@Override
public boolean canBeCompared(short controlType, short testType) {
return controlType == testType
|| (controlType == CDATA && testType == TEXT)
|| (controlType == TEXT && testType == CDATA);
}
}
}