我正在尝试对生成xml的一些方法进行单元测试。我有一个预期的xml字符串和结果字符串，在googling和搜索堆栈溢出后，我找到了XMLUnit。但是，它似乎并不处理一种特殊情况，即不同顺序中的重复元素包含不同顺序的元素。例如：
预期的XML：
<graph>
<parent>
<foo>David</foo>
<bar>Rosalyn</bar>
</parent>
<parent>
<bar>Alexander</bar>
<foo>Linda</foo>
</parent>
</graph>
实际XML：
<graph>
<parent>
<foo>Linda</foo>
<bar>Alexander</bar>
</parent>
<parent>
<bar>Rosalyn</bar>
<foo>David</foo>
</parent>
</graph>
您可以看到父节点重复，其内容可以按任何顺序排列。这两个xml片段应该是等价的，但是我看到的stackoverflow示例中没有任何内容可以解决这个问题。 （Best way to compare 2 XML documents in Java） （How can I compare two similar XML files in XMLUnit）
我已经尝试从xml字符串创建Documents，逐步遍历每个预期的父节点，然后将它与每个实际的父节点进行比较，看看其中一个是否等效。
在我看来，对于一些应该是相对常见的比较的东西来说，重新发明轮子。 XMLUnit似乎做了很多，也许我错过了一些东西，但从我所知道的，它在这个特殊情况下不足。
有更简单/更好的方法吗？
我的解决方案：
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setCoalescing(true);
dbf.setIgnoringElementContentWhitespace(true);
dbf.setIgnoringComments(true);
DocumentBuilder db = dbf.newDocumentBuilder();
// parse and normalize expected xml
Document expectedXMLDoc = db.parse(new ByteArrayInputStream(resultXML.getBytes()));
expectedXMLDoc.normalizeDocument();
// parse and normalize actual xml
Document actualXMLDoc = db.parse(new ByteArrayInputStream(actual.getXml().getBytes()));
actualXMLDoc.normalizeDocument();
// expected and actual parent nodes
NodeList expectedParentNodes = expectedXMLDoc.getLastChild().getChildNodes();
NodeList actualParentNodes = actualXMLDoc.getLastChild().getChildNodes();
// assert same amount of nodes in actual and expected
assertEquals("actual XML does not have expected amount of Parent nodes", expectedParentNodes.getLength(), actualParentNodes.getLength());
// loop through expected parent nodes
for(int i=0; i < expectedParentNodes.getLength(); i++) {
// create doc from node
Node expectedParentNode = expectedParentNodes.item(i);
Document expectedParentDoc = db.newDocument();
Node importedExpectedNode = expectedParentDoc.importNode(expectedParentNode, true);
expectedParentDoc.appendChild(importedExpectedNode);
boolean hasSimilar = false;
StringBuilder messages = new StringBuilder();
// for each expected parent, find a similar parent
for(int j=0; j < actualParentNodes.getLength(); j++) {
// create doc from node
Node actualParentNode = actualParentNodes.item(j);
Document actualParentDoc = db.newDocument();
Node importedActualNode = actualParentDoc.importNode(actualParentNode, true);
actualParentDoc.appendChild(importedActualNode);
// XMLUnit Diff
Diff diff = new Diff(expectedParentDoc, actualParentDoc);
messages.append(diff.toString());
boolean similar = diff.similar();
if(similar) {
hasSimilar = true;
}
}
// assert it found a similar parent node
assertTrue("expected and actual XML nodes are not equivalent " + messages, hasSimilar);
}
答案 0 :(得分：1)
使用带有添加<xsl:sort.../>的XSL身份转换按名称重新排序每个文档中的节点，然后比较排序的输出。对于某些节点（即顶级父节点），您可能需要使用特定的排序键来对内部内容进行排序。
这是一个让你入门的骨架：
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" indent="yes"/>
<!-- Identity Transform -->
<xsl:template match="@*|node()">
<xsl:copy>
<xsl:apply-templates select="@*|node()">
<xsl:sort select="name(.)"/>
</xsl:apply-templates>
</xsl:copy>
</xsl:template>
<!-- Special handling for graph/parent nodes -->
<xsl:template match="graph">
<!-- Sort attributes using default above -->
<xsl:apply-templates select="@*"/>
<!-- Sort parent nodes by text of bar node -->
<xsl:apply-templates select="parent">
<xsl:sort select="bar/text()"/>
</xsl:apply-templates>
</xsl:template>
</xsl:stylesheet>
这适用于您发布的样本。根据实际数据的需要进行调整。
答案 1 :(得分：0)
您可以使用递归函数，因此它可以用于任何元素顺序不重要的xml结构，这里是伪代码：
public boolean isEqual(Node node1, Node node2)
{
if nodes are not from the same type
return false;
if values of them are not the same
return false;
if size of their children are not the same
return false;
if they have no children
return true;
//compares each children of the node1 with the first child of node2
for each child node of node1
if(isEqual(node2.child(0), node)
{
matchFound = true;
break;
}
if(!matchFound)
return false;
remove matched node from children of node1;
remove matched node from children of node2;
return isEqual(node1, node2)
}
答案 2 :(得分：0)
刚才意识到我没有为此选择答案。我最终使用了与我的解决方案非常相似的东西。这是对我有用的最终解决方案。我把它包装在一个类中以与junit一起使用，因此这些方法可以像任何其他junit断言一样使用。
如果所有孩子都需要整理，就像我的情况一样，你可以运行
assertEquivalentXml(expectedXML, testXML, null, null);
如果某些节点需要按随机顺序生成子节点和/或某些属性需要忽略：
assertEquivalentXml(expectedXML, testXML,
new String[]{"dataset", "categories"}, new String[]{"color", "anchorBorderColor", "anchorBgColor"});
这是班级：
/**
* A set of methods that assert XML equivalence specifically for XmlProvider classes. Extends
* <code>junit.framework.Assert</code>, meaning that these methods are recognised as assertions by junit.
*
* @author munick
*/
public class XmlProviderAssertions extends Assert {
/**
* Asserts two xml strings are equivalent. Nodes are not expected to be in order. Order can be compared among the
* children of the top parent node by adding their names to nodesWithOrderedChildren
* (e.g. in <graph><dataset><set value="1"/><set value="2"/></dataset></graph> the top parent node is graph
* and we can expect the children of dataset to be in order by adding "dataset" to nodesWithOrderedChildren).
*
* All attribute names and values are compared unless their name is in attributesToIgnore in which case only the
* name is compared and any difference in value is ignored.
*
* @param expectedXML the expected xml string
* @param testXML the xml string being tested
* @param nodesWithOrderedChildren names of nodes who's children should be in order
* @param attributesToIgnore names of attributes who's values should be ignored
*/
public static void assertEquivalentXml(String expectedXML, String testXML, String[] nodesWithOrderedChildren, String[] attributesToIgnore) {
Set<String> setOfNodesWithOrderedChildren = new HashSet<String>();
if(nodesWithOrderedChildren != null ) {
Collections.addAll(setOfNodesWithOrderedChildren, nodesWithOrderedChildren);
}
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setCoalescing(true);
dbf.setIgnoringElementContentWhitespace(true);
dbf.setIgnoringComments(true);
DocumentBuilder db = null;
try {
db = dbf.newDocumentBuilder();
} catch (ParserConfigurationException e) {
fail("Error testing XML");
}
Document expectedXMLDoc = null;
Document testXMLDoc = null;
try {
expectedXMLDoc = db.parse(new ByteArrayInputStream(expectedXML.getBytes()));
expectedXMLDoc.normalizeDocument();
testXMLDoc = db.parse(new ByteArrayInputStream(testXML.getBytes()));
testXMLDoc.normalizeDocument();
} catch (SAXException e) {
fail("Could not parse testXML");
} catch (IOException e) {
fail("Could not read testXML");
}
NodeList expectedChildNodes = expectedXMLDoc.getLastChild().getChildNodes();
NodeList testChildNodes = testXMLDoc.getLastChild().getChildNodes();
assertEquals("Test XML does not have expected amount of child nodes", expectedChildNodes.getLength(), testChildNodes.getLength());
//compare parent nodes
Document expectedDEDoc = getNodeAsDocument(expectedXMLDoc.getDocumentElement(), db, false);
Document testDEDoc = getNodeAsDocument(testXMLDoc.getDocumentElement(), db, false);
Diff diff = new Diff(expectedDEDoc, testDEDoc);
assertTrue("Test XML parent node doesn't match expected XML parent node. " + diff.toString(), diff.similar());
// compare child nodes
for(int i=0; i < expectedChildNodes.getLength(); i++) {
// expected child node
Node expectedChildNode = expectedChildNodes.item(i);
// skip text nodes
if( expectedChildNode.getNodeType() == Node.TEXT_NODE ) {
continue;
}
// convert to document to use in Diff
Document expectedChildDoc = getNodeAsDocument(expectedChildNode, db, true);
boolean hasSimilar = false;
StringBuilder messages = new StringBuilder();
for(int j=0; j < testChildNodes.getLength(); j++) {
// find child node in test xml
Node testChildNode = testChildNodes.item(j);
// skip text nodes
if( testChildNode.getNodeType() == Node.TEXT_NODE ) {
continue;
}
// create doc from node
Document testChildDoc = getNodeAsDocument(testChildNode, db, true);
diff = new Diff(expectedChildDoc, testChildDoc);
// if it doesn't contain order specific nodes, then use the elem and attribute qualifier, otherwise use the default
if( !setOfNodesWithOrderedChildren.contains( expectedChildDoc.getDocumentElement().getNodeName() ) ) {
diff.overrideElementQualifier(new ElementNameAndAttributeQualifier());
}
if(attributesToIgnore != null) {
diff.overrideDifferenceListener(new IgnoreNamedAttributesDifferenceListener(attributesToIgnore));
}
messages.append(diff.toString());
boolean similar = diff.similar();
if(similar) {
hasSimilar = true;
}
}
assertTrue("Test XML does not match expected XML. " + messages, hasSimilar);
}
}
private static Document getNodeAsDocument(Node node, DocumentBuilder db, boolean deep) {
// create doc from node
Document nodeDoc = db.newDocument();
Node importedNode = nodeDoc.importNode(node, deep);
nodeDoc.appendChild(importedNode);
return nodeDoc;
}
}
/**
* Custom difference listener that ignores differences in attribute values for specified attribute names. Used to
* ignore color attribute differences in FusionChartXml equivalence.
*/
class IgnoreNamedAttributesDifferenceListener implements DifferenceListener {
Set<String> attributeBlackList;
public IgnoreNamedAttributesDifferenceListener(String[] attributeNames) {
attributeBlackList = new HashSet<String>();
Collections.addAll(attributeBlackList, attributeNames);
}
public int differenceFound(Difference difference) {
int differenceId = difference.getId();
if (differenceId == DifferenceConstants.ATTR_VALUE_ID) {
if(attributeBlackList.contains(difference.getControlNodeDetail().getNode().getNodeName())) {
return DifferenceListener.RETURN_IGNORE_DIFFERENCE_NODES_IDENTICAL;
}
}
return DifferenceListener.RETURN_ACCEPT_DIFFERENCE;
}
public void skippedComparison(Node node, Node node1) {
// left empty
}
}