在Java中比较2个XML文档的最佳方法

在Java中比较2个XML文档的最佳方法,java,xml,testing,parsing,comparison,Java,Xml,Testing,Parsing,Comparison,我正在尝试编写一个应用程序的自动测试,该应用程序基本上将自定义消息格式转换为XML消息,并将其发送到另一端。我有一组很好的输入/输出消息对,所以我所需要做的就是发送输入消息,并侦听XML消息从另一端出来 当需要比较实际输出和预期输出时,我遇到了一些问题。我的第一个想法就是对预期消息和实际消息进行字符串比较。这样做效果不太好,因为我们的示例数据的格式并不总是一致的,而且XML名称空间经常使用不同的别名(有时根本不使用名称空间) 我知道我可以解析两个字符串,然后自己遍历每个元素并比较它们,这不会太困

我正在尝试编写一个应用程序的自动测试,该应用程序基本上将自定义消息格式转换为XML消息,并将其发送到另一端。我有一组很好的输入/输出消息对,所以我所需要做的就是发送输入消息,并侦听XML消息从另一端出来

当需要比较实际输出和预期输出时,我遇到了一些问题。我的第一个想法就是对预期消息和实际消息进行字符串比较。这样做效果不太好,因为我们的示例数据的格式并不总是一致的,而且XML名称空间经常使用不同的别名(有时根本不使用名称空间)

我知道我可以解析两个字符串,然后自己遍历每个元素并比较它们,这不会太困难,但我觉得有更好的方法或库可以利用

因此,归结起来,问题是:

给定两个都包含有效XML的Java字符串,如何确定它们在语义上是否等价?如果您有办法确定差异是什么,您将获得额外的积分。

有一个规范化工具,可以将DOM转换为常规形式,然后您可以对其进行字符串化和比较。因此,无论空白不规则或属性排序如何,您都可以对文档进行定期、可预测的比较


这在具有专用可视字符串比较器的IDE中尤其有效,如Eclipse。您可以直观地表示文档之间的语义差异。

听起来像是XMLUnit的工作

例如:

public class SomeTest extends XMLTestCase {
  @Test
  public void test() {
    String xml1 = ...
    String xml2 = ...

    XMLUnit.setIgnoreWhitespace(true); // ignore whitespace differences

    // can also compare xml Documents, InputSources, Readers, Diffs
    assertXMLEqual(xml1, xml2);  // assertXMLEquals comes from XMLTestCase
  }
}

斯卡夫曼似乎给出了一个很好的答案

另一种方法可能是使用commmand行实用程序(如xmlstarlet())格式化XML,然后格式化两个字符串,然后使用任何diff实用程序(库)来区分结果输出文件。我不知道当名称空间出现问题时,这是否是一个好的解决方案。

既然您说的是“语义等效”,我想您的意思是,您想做的不仅仅是验证xml输出(字符串)是否相等,以及您想做什么

这里有些东西

这里有些东西

一定要读同等的书。最终,你如何定义“语义等价”对于你从中重构消息的任何对象都很重要。只需从消息中构建该对象,并使用自定义的equals()来定义要查找的内容。

我正在使用的equals具有从结构上比较XML文件的选项(忽略字符串数据)

这意味着(如果选中“忽略文本”选项):

xxx

yyy

在结构平等的意义上是平等的。如果您有数据不同但结构不同的示例文件,这将非常方便

下面将使用标准JDK库检查文档是否相等

DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); dbf.setNamespaceAware(true); dbf.setCoalescing(true); dbf.setIgnoringElementContentWhitespace(true); dbf.setIgnoringComments(true); DocumentBuilder db = dbf.newDocumentBuilder(); Document doc1 = db.parse(new File("file1.xml")); doc1.normalizeDocument(); Document doc2 = db.parse(new File("file2.xml")); doc2.normalizeDocument(); Assert.assertTrue(doc1.isEqualNode(doc2)); DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance(); dbf.setNamespaceAware(true); dbf.setCoalescing(真);
dbf.setIgnoringElementContentWhitespace(true); dbf.setIgnoringComments(true); DocumentBuilder db=dbf.newDocumentBuilder(); documentdoc1=db.parse(新文件(“file1.xml”); doc1.规范化文档(); Document doc2=db.parse(新文件(“file2.xml”); doc2.规范化文档(); Assert.assertTrue(doc1.isEqualNode(doc2)); normalize()用于确保没有循环(技术上不会有循环)


但是,上面的代码要求元素中的空格相同,因为它保留并计算它。Java附带的标准XML解析器不允许您设置功能来提供规范版本或理解
XML:space
如果这是一个问题,那么您可能需要一个替代的XML解析器,如xerces或使用JDOM。

谢谢,我扩展了这个,试试这个

import java.io.ByteArrayInputStream;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;

public class XmlDiff 
{
    private boolean nodeTypeDiff = true;
    private boolean nodeValueDiff = true;

    public boolean diff( String xml1, String xml2, List<String> diffs ) throws Exception
    {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        dbf.setNamespaceAware(true);
        dbf.setCoalescing(true);
        dbf.setIgnoringElementContentWhitespace(true);
        dbf.setIgnoringComments(true);
        DocumentBuilder db = dbf.newDocumentBuilder();


        Document doc1 = db.parse(new ByteArrayInputStream(xml1.getBytes()));
        Document doc2 = db.parse(new ByteArrayInputStream(xml2.getBytes()));

        doc1.normalizeDocument();
        doc2.normalizeDocument();

        return diff( doc1, doc2, diffs );

    }

    /**
     * Diff 2 nodes and put the diffs in the list 
     */
    public boolean diff( Node node1, Node node2, List<String> diffs ) throws Exception
    {
        if( diffNodeExists( node1, node2, diffs ) )
        {
            return true;
        }

        if( nodeTypeDiff )
        {
            diffNodeType(node1, node2, diffs );
        }

        if( nodeValueDiff )
        {
            diffNodeValue(node1, node2, diffs );
        }


        System.out.println(node1.getNodeName() + "/" + node2.getNodeName());

        diffAttributes( node1, node2, diffs );
        diffNodes( node1, node2, diffs );

        return diffs.size() > 0;
    }

    /**
     * Diff the nodes
     */
    public boolean diffNodes( Node node1, Node node2, List<String> diffs ) throws Exception
    {
        //Sort by Name
        Map<String,Node> children1 = new LinkedHashMap<String,Node>();      
        for( Node child1 = node1.getFirstChild(); child1 != null; child1 = child1.getNextSibling() )
        {
            children1.put( child1.getNodeName(), child1 );
        }

        //Sort by Name
        Map<String,Node> children2 = new LinkedHashMap<String,Node>();      
        for( Node child2 = node2.getFirstChild(); child2!= null; child2 = child2.getNextSibling() )
        {
            children2.put( child2.getNodeName(), child2 );
        }

        //Diff all the children1
        for( Node child1 : children1.values() )
        {
            Node child2 = children2.remove( child1.getNodeName() );
            diff( child1, child2, diffs );
        }

        //Diff all the children2 left over
        for( Node child2 : children2.values() )
        {
            Node child1 = children1.get( child2.getNodeName() );
            diff( child1, child2, diffs );
        }

        return diffs.size() > 0;
    }


    /**
     * Diff the nodes
     */
    public boolean diffAttributes( Node node1, Node node2, List<String> diffs ) throws Exception
    {        
        //Sort by Name
        NamedNodeMap nodeMap1 = node1.getAttributes();
        Map<String,Node> attributes1 = new LinkedHashMap<String,Node>();        
        for( int index = 0; nodeMap1 != null && index < nodeMap1.getLength(); index++ )
        {
            attributes1.put( nodeMap1.item(index).getNodeName(), nodeMap1.item(index) );
        }

        //Sort by Name
        NamedNodeMap nodeMap2 = node2.getAttributes();
        Map<String,Node> attributes2 = new LinkedHashMap<String,Node>();        
        for( int index = 0; nodeMap2 != null && index < nodeMap2.getLength(); index++ )
        {
            attributes2.put( nodeMap2.item(index).getNodeName(), nodeMap2.item(index) );

        }

        //Diff all the attributes1
        for( Node attribute1 : attributes1.values() )
        {
            Node attribute2 = attributes2.remove( attribute1.getNodeName() );
            diff( attribute1, attribute2, diffs );
        }

        //Diff all the attributes2 left over
        for( Node attribute2 : attributes2.values() )
        {
            Node attribute1 = attributes1.get( attribute2.getNodeName() );
            diff( attribute1, attribute2, diffs );
        }

        return diffs.size() > 0;
    }
    /**
     * Check that the nodes exist
     */
    public boolean diffNodeExists( Node node1, Node node2, List<String> diffs ) throws Exception
    {
        if( node1 == null && node2 == null )
        {
            diffs.add( getPath(node2) + ":node " + node1 + "!=" + node2 + "\n" );
            return true;
        }

        if( node1 == null && node2 != null )
        {
            diffs.add( getPath(node2) + ":node " + node1 + "!=" + node2.getNodeName() );
            return true;
        }

        if( node1 != null && node2 == null )
        {
            diffs.add( getPath(node1) + ":node " + node1.getNodeName() + "!=" + node2 );
            return true;
        }

        return false;
    }

    /**
     * Diff the Node Type
     */
    public boolean diffNodeType( Node node1, Node node2, List<String> diffs ) throws Exception
    {       
        if( node1.getNodeType() != node2.getNodeType() ) 
        {
            diffs.add( getPath(node1) + ":type " + node1.getNodeType() + "!=" + node2.getNodeType() );
            return true;
        }

        return false;
    }

    /**
     * Diff the Node Value
     */
    public boolean diffNodeValue( Node node1, Node node2, List<String> diffs ) throws Exception
    {       
        if( node1.getNodeValue() == null && node2.getNodeValue() == null )
        {
            return false;
        }

        if( node1.getNodeValue() == null && node2.getNodeValue() != null )
        {
            diffs.add( getPath(node1) + ":type " + node1 + "!=" + node2.getNodeValue() );
            return true;
        }

        if( node1.getNodeValue() != null && node2.getNodeValue() == null )
        {
            diffs.add( getPath(node1) + ":type " + node1.getNodeValue() + "!=" + node2 );
            return true;
        }

        if( !node1.getNodeValue().equals( node2.getNodeValue() ) )
        {
            diffs.add( getPath(node1) + ":type " + node1.getNodeValue() + "!=" + node2.getNodeValue() );
            return true;
        }

        return false;
    }


    /**
     * Get the node path
     */
    public String getPath( Node node )
    {
        StringBuilder path = new StringBuilder();

        do
        {           
            path.insert(0, node.getNodeName() );
            path.insert( 0, "/" );
        }
        while( ( node = node.getParentNode() ) != null );

        return path.toString();
    }
}
import java.io.ByteArrayInputStream;
导入java.util.LinkedHashMap;
导入java.util.List;
导入java.util.Map;
导入javax.xml.parsers.DocumentBuilder;
导入javax.xml.parsers.DocumentBuilderFactory;
导入org.w3c.dom.Document;
导入org.w3c.dom.NamedNodeMap;
导入org.w3c.dom.Node;
公共类XmlDiff
{
私有布尔nodeTypeDiff=true;
私有布尔nodeValueDiff=true;
公共布尔差异(字符串xml1、字符串xml2、列表差异)引发异常
{
DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
dbf.setNamespaceAware(true);
dbf.setCoalescing(真);

dbf.setIgnoringElementContentWhitespace(true); dbf.setIgnoringComments(true); DocumentBuilder db=dbf.newDocumentBuilder(); Document doc1=db.parse(新的ByteArrayInputStream(xml1.getBytes()); Document doc2=db.parse(新的ByteArrayInputStream(xml2.getBytes()); doc1.规范化文档(); doc2.规范化文档(); 返回差异(doc1、doc2、差异); } /** *Diff 2节点并将Diff放入列表中 */ 公共布尔差异(节点node1、节点node2、列表差异)引发异常 { if(diffNodeExists(node1、node2、diffs)) { 返回true; } if(nodeTypeDiff) { diffNodeType(node1、node2、diffs); } if(nodeValueDiff) { diffNodeValue(节点1、节点2、diffs); } System.out.println(node1.getNodeName()+“/”+node2.getNodeName()); diffAttributes(节点1、节点2、diffs); diffNodes(节点1、节点2、diffs); 返回差异大小()>0; } /** *区分节点 */ 公共布尔diffNodes(节点node1、节点node2、列表差异)引发异常 { //按名称排序 Map children1=新建LinkedHashMap(); 对于(Node child1=node1.getFirstChild();child1= DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); dbf.setNamespaceAware(true); dbf.setCoalescing(true); dbf.setIgnoringElementContentWhitespace(true); dbf.setIgnoringComments(true); DocumentBuilder db = dbf.newDocumentBuilder(); Document doc1 = db.parse(new File("file1.xml")); doc1.normalizeDocument(); Document doc2 = db.parse(new File("file2.xml")); doc2.normalizeDocument(); Assert.assertTrue(doc1.isEqualNode(doc2));
import java.io.ByteArrayInputStream;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;

public class XmlDiff 
{
    private boolean nodeTypeDiff = true;
    private boolean nodeValueDiff = true;

    public boolean diff( String xml1, String xml2, List<String> diffs ) throws Exception
    {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        dbf.setNamespaceAware(true);
        dbf.setCoalescing(true);
        dbf.setIgnoringElementContentWhitespace(true);
        dbf.setIgnoringComments(true);
        DocumentBuilder db = dbf.newDocumentBuilder();


        Document doc1 = db.parse(new ByteArrayInputStream(xml1.getBytes()));
        Document doc2 = db.parse(new ByteArrayInputStream(xml2.getBytes()));

        doc1.normalizeDocument();
        doc2.normalizeDocument();

        return diff( doc1, doc2, diffs );

    }

    /**
     * Diff 2 nodes and put the diffs in the list 
     */
    public boolean diff( Node node1, Node node2, List<String> diffs ) throws Exception
    {
        if( diffNodeExists( node1, node2, diffs ) )
        {
            return true;
        }

        if( nodeTypeDiff )
        {
            diffNodeType(node1, node2, diffs );
        }

        if( nodeValueDiff )
        {
            diffNodeValue(node1, node2, diffs );
        }


        System.out.println(node1.getNodeName() + "/" + node2.getNodeName());

        diffAttributes( node1, node2, diffs );
        diffNodes( node1, node2, diffs );

        return diffs.size() > 0;
    }

    /**
     * Diff the nodes
     */
    public boolean diffNodes( Node node1, Node node2, List<String> diffs ) throws Exception
    {
        //Sort by Name
        Map<String,Node> children1 = new LinkedHashMap<String,Node>();      
        for( Node child1 = node1.getFirstChild(); child1 != null; child1 = child1.getNextSibling() )
        {
            children1.put( child1.getNodeName(), child1 );
        }

        //Sort by Name
        Map<String,Node> children2 = new LinkedHashMap<String,Node>();      
        for( Node child2 = node2.getFirstChild(); child2!= null; child2 = child2.getNextSibling() )
        {
            children2.put( child2.getNodeName(), child2 );
        }

        //Diff all the children1
        for( Node child1 : children1.values() )
        {
            Node child2 = children2.remove( child1.getNodeName() );
            diff( child1, child2, diffs );
        }

        //Diff all the children2 left over
        for( Node child2 : children2.values() )
        {
            Node child1 = children1.get( child2.getNodeName() );
            diff( child1, child2, diffs );
        }

        return diffs.size() > 0;
    }


    /**
     * Diff the nodes
     */
    public boolean diffAttributes( Node node1, Node node2, List<String> diffs ) throws Exception
    {        
        //Sort by Name
        NamedNodeMap nodeMap1 = node1.getAttributes();
        Map<String,Node> attributes1 = new LinkedHashMap<String,Node>();        
        for( int index = 0; nodeMap1 != null && index < nodeMap1.getLength(); index++ )
        {
            attributes1.put( nodeMap1.item(index).getNodeName(), nodeMap1.item(index) );
        }

        //Sort by Name
        NamedNodeMap nodeMap2 = node2.getAttributes();
        Map<String,Node> attributes2 = new LinkedHashMap<String,Node>();        
        for( int index = 0; nodeMap2 != null && index < nodeMap2.getLength(); index++ )
        {
            attributes2.put( nodeMap2.item(index).getNodeName(), nodeMap2.item(index) );

        }

        //Diff all the attributes1
        for( Node attribute1 : attributes1.values() )
        {
            Node attribute2 = attributes2.remove( attribute1.getNodeName() );
            diff( attribute1, attribute2, diffs );
        }

        //Diff all the attributes2 left over
        for( Node attribute2 : attributes2.values() )
        {
            Node attribute1 = attributes1.get( attribute2.getNodeName() );
            diff( attribute1, attribute2, diffs );
        }

        return diffs.size() > 0;
    }
    /**
     * Check that the nodes exist
     */
    public boolean diffNodeExists( Node node1, Node node2, List<String> diffs ) throws Exception
    {
        if( node1 == null && node2 == null )
        {
            diffs.add( getPath(node2) + ":node " + node1 + "!=" + node2 + "\n" );
            return true;
        }

        if( node1 == null && node2 != null )
        {
            diffs.add( getPath(node2) + ":node " + node1 + "!=" + node2.getNodeName() );
            return true;
        }

        if( node1 != null && node2 == null )
        {
            diffs.add( getPath(node1) + ":node " + node1.getNodeName() + "!=" + node2 );
            return true;
        }

        return false;
    }

    /**
     * Diff the Node Type
     */
    public boolean diffNodeType( Node node1, Node node2, List<String> diffs ) throws Exception
    {       
        if( node1.getNodeType() != node2.getNodeType() ) 
        {
            diffs.add( getPath(node1) + ":type " + node1.getNodeType() + "!=" + node2.getNodeType() );
            return true;
        }

        return false;
    }

    /**
     * Diff the Node Value
     */
    public boolean diffNodeValue( Node node1, Node node2, List<String> diffs ) throws Exception
    {       
        if( node1.getNodeValue() == null && node2.getNodeValue() == null )
        {
            return false;
        }

        if( node1.getNodeValue() == null && node2.getNodeValue() != null )
        {
            diffs.add( getPath(node1) + ":type " + node1 + "!=" + node2.getNodeValue() );
            return true;
        }

        if( node1.getNodeValue() != null && node2.getNodeValue() == null )
        {
            diffs.add( getPath(node1) + ":type " + node1.getNodeValue() + "!=" + node2 );
            return true;
        }

        if( !node1.getNodeValue().equals( node2.getNodeValue() ) )
        {
            diffs.add( getPath(node1) + ":type " + node1.getNodeValue() + "!=" + node2.getNodeValue() );
            return true;
        }

        return false;
    }


    /**
     * Get the node path
     */
    public String getPath( Node node )
    {
        StringBuilder path = new StringBuilder();

        do
        {           
            path.insert(0, node.getNodeName() );
            path.insert( 0, "/" );
        }
        while( ( node = node.getParentNode() ) != null );

        return path.toString();
    }
}
    import com.a7soft.examxml.ExamXML;
    import com.a7soft.examxml.Options;

       .................

       // Reads two XML files into two strings
       String s1 = readFile("orders1.xml");
       String s2 = readFile("orders.xml");

       // Loads options saved in a property file
       Options.loadOptions("options");

       // Compares two Strings representing XML entities
       System.out.println( ExamXML.compareXMLString( s1, s2 ) );
import org.custommonkey.xmlunit.DetailedDiff;
import org.custommonkey.xmlunit.XMLUnit;
import org.junit.Assert;

public class TestXml {

    public static void main(String[] args) throws Exception {
        String result = "<abc             attr=\"value1\"                title=\"something\">            </abc>";
        // will be ok
        assertXMLEquals("<abc attr=\"value1\" title=\"something\"></abc>", result);
    }

    public static void assertXMLEquals(String expectedXML, String actualXML) throws Exception {
        XMLUnit.setIgnoreWhitespace(true);
        XMLUnit.setIgnoreAttributeOrder(true);

        DetailedDiff diff = new DetailedDiff(XMLUnit.compareXML(expectedXML, actualXML));

        List<?> allDifferences = diff.getAllDifferences();
        Assert.assertEquals("Differences found: "+ diff.toString(), 0, allDifferences.size());
    }

}
<dependency>
    <groupId>xmlunit</groupId>
    <artifactId>xmlunit</artifactId>
    <version>1.4</version>
</dependency>
import org.apache.xml.security.c14n.CanonicalizationException;
import org.apache.xml.security.c14n.Canonicalizer;
import org.apache.xml.security.c14n.InvalidCanonicalizerException;
import org.w3c.dom.Element;
import org.w3c.dom.bootstrap.DOMImplementationRegistry;
import org.w3c.dom.ls.DOMImplementationLS;
import org.w3c.dom.ls.LSSerializer;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.TransformerException;
import java.io.IOException;
import java.io.StringReader;

import static org.apache.xml.security.Init.init;
import static org.junit.Assert.assertEquals;

public class XmlUtils {
    static {
        init();
    }

    public static String toCanonicalXml(String xml) throws InvalidCanonicalizerException, ParserConfigurationException, SAXException, CanonicalizationException, IOException {
        Canonicalizer canon = Canonicalizer.getInstance(Canonicalizer.ALGO_ID_C14N_OMIT_COMMENTS);
        byte canonXmlBytes[] = canon.canonicalize(xml.getBytes());
        return new String(canonXmlBytes);
    }

    public static String prettyFormat(String input) throws TransformerException, ParserConfigurationException, IOException, SAXException, InstantiationException, IllegalAccessException, ClassNotFoundException {
        InputSource src = new InputSource(new StringReader(input));
        Element document = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(src).getDocumentElement();
        Boolean keepDeclaration = input.startsWith("<?xml");
        DOMImplementationRegistry registry = DOMImplementationRegistry.newInstance();
        DOMImplementationLS impl = (DOMImplementationLS) registry.getDOMImplementation("LS");
        LSSerializer writer = impl.createLSSerializer();
        writer.getDomConfig().setParameter("format-pretty-print", Boolean.TRUE);
        writer.getDomConfig().setParameter("xml-declaration", keepDeclaration);
        return writer.writeToString(document);
    }

    public static void assertXMLEqual(String expected, String actual) throws ParserConfigurationException, IOException, SAXException, CanonicalizationException, InvalidCanonicalizerException, TransformerException, IllegalAccessException, ClassNotFoundException, InstantiationException {
        String canonicalExpected = prettyFormat(toCanonicalXml(expected));
        String canonicalActual = prettyFormat(toCanonicalXml(actual));
        assertEquals(canonicalExpected, canonicalActual);
    }
}
    <dependency>
        <groupId>org.xmlunit</groupId>
        <artifactId>xmlunit-core</artifactId>
        <version>2.0.0</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.xmlunit</groupId>
        <artifactId>xmlunit-matchers</artifactId>
        <version>2.0.0</version>
        <scope>test</scope>
    </dependency>
import static org.junit.Assert.assertThat;
import static org.xmlunit.matchers.CompareMatcher.isIdenticalTo;
import org.xmlunit.builder.Input;
import org.xmlunit.input.WhitespaceStrippedSource;

public class SomeTest extends XMLTestCase {
    @Test
    public void test() {
        String result = "<root></root>";
        String expected = "<root>  </root>";

        // ignore whitespace differences
        // https://github.com/xmlunit/user-guide/wiki/Providing-Input-to-XMLUnit#whitespacestrippedsource
        assertThat(result, isIdenticalTo(new WhitespaceStrippedSource(Input.from(expected).build())));

        assertThat(result, isIdenticalTo(Input.from(expected).build())); // will fail due to whitespace differences
    }
}
String expectedXml = "<foo />";
String actualXml = "<bar />";
assertThat(actualXml).isXmlEqualTo(expectedXml);
import java.io.ByteArrayInputStream;
import java.nio.charset.Charset;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.junit.Assert;
import org.w3c.dom.Document;

/**
 * Asserts for asserting XML strings.
 */
public final class AssertXml {

    private AssertXml() {
    }

    private static Pattern NAMESPACE_PATTERN = Pattern.compile("xmlns:(ns\\d+)=\"(.*?)\"");

    /**
     * Asserts that two XML are of identical content (namespace aliases are ignored).
     * 
     * @param expectedXml expected XML
     * @param actualXml actual XML
     * @throws Exception thrown if XML parsing fails
     */
    public static void assertEqualXmls(String expectedXml, String actualXml) throws Exception {
        // Find all namespace mappings
        Map<String, String> fullnamespace2newAlias = new HashMap<String, String>();
        generateNewAliasesForNamespacesFromXml(expectedXml, fullnamespace2newAlias);
        generateNewAliasesForNamespacesFromXml(actualXml, fullnamespace2newAlias);

        for (Entry<String, String> entry : fullnamespace2newAlias.entrySet()) {
            String newAlias = entry.getValue();
            String namespace = entry.getKey();
            Pattern nsReplacePattern = Pattern.compile("xmlns:(ns\\d+)=\"" + namespace + "\"");
            expectedXml = transletaNamespaceAliasesToNewAlias(expectedXml, newAlias, nsReplacePattern);
            actualXml = transletaNamespaceAliasesToNewAlias(actualXml, newAlias, nsReplacePattern);
        }

        // nomralize namespaces accoring to given mapping

        DocumentBuilder db = initDocumentParserFactory();

        Document expectedDocuemnt = db.parse(new ByteArrayInputStream(expectedXml.getBytes(Charset.forName("UTF-8"))));
        expectedDocuemnt.normalizeDocument();

        Document actualDocument = db.parse(new ByteArrayInputStream(actualXml.getBytes(Charset.forName("UTF-8"))));
        actualDocument.normalizeDocument();

        if (!expectedDocuemnt.isEqualNode(actualDocument)) {
            Assert.assertEquals(expectedXml, actualXml); //just to better visualize the diffeences i.e. in eclipse
        }
    }


    private static DocumentBuilder initDocumentParserFactory() throws ParserConfigurationException {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        dbf.setNamespaceAware(false);
        dbf.setCoalescing(true);
        dbf.setIgnoringElementContentWhitespace(true);
        dbf.setIgnoringComments(true);
        DocumentBuilder db = dbf.newDocumentBuilder();
        return db;
    }

    private static String transletaNamespaceAliasesToNewAlias(String xml, String newAlias, Pattern namespacePattern) {
        Matcher nsMatcherExp = namespacePattern.matcher(xml);
        if (nsMatcherExp.find()) {
            xml = xml.replaceAll(nsMatcherExp.group(1) + "[:]", newAlias + ":");
            xml = xml.replaceAll(nsMatcherExp.group(1) + "=", newAlias + "=");
        }
        return xml;
    }

    private static void generateNewAliasesForNamespacesFromXml(String xml, Map<String, String> fullnamespace2newAlias) {
        Matcher nsMatcher = NAMESPACE_PATTERN.matcher(xml);
        while (nsMatcher.find()) {
            if (!fullnamespace2newAlias.containsKey(nsMatcher.group(2))) {
                fullnamespace2newAlias.put(nsMatcher.group(2), "nsTr" + (fullnamespace2newAlias.size() + 1));
            }
        }
    }

}
String xml1 = ...
String xml2 = ...
XMLUnit.setIgnoreWhitespace(true);
XMLUnit.setIgnoreAttributeOrder(true);
XMLAssert.assertXMLEqual(actualxml, xmlInDb);