How to pass a XML document to XSL file using Javax.xml.transformer API?

Question

I am using javax.xml.transform API to do XSL transformation . The API only allows one XML document as an input to apply transformation as below .

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    StringWriter stringWriter = new StringWriter();
    File xml = new File("C:\\abc");
    File xsl = new File("C:\\def.xsl");
    factory.setNamespaceAware(true);
    DocumentBuilder builder = factory.newDocumentBuilder();
    document = builder.parse(xml);
    TransformerFactory transformerFactory = 
    TransformerFactory.newInstance();
    StreamSource style = new StreamSource(xsl);
    Transformer transformer = transformerFactory.newTransformer(style);
    DOMSource source = new DOMSource(document);

Also , can pass simple String params as below , without any issue as below :

transformer.setParameter("mode", "CREATE");

But , i want to pass an XML Document as a parameter to the XSL file . I tried below code as suggested on one of SO pages , as below :

DocumentBuilder builder = factory.newDocumentBuilder();
 final Document documentFile = builder.parse(xml2);
 Map<String, Document> docs = new HashMap<String, Document>();
 docs.put("lookup", documentFile);
 transformer.setURIResolver(new DocumentURIResolver(docs));

And i set , the tag in XML to receive value as below :

<xsl:variable name="lookup" select="('documentFile')/>  . 

But its not working for me . Can anyone help me out with the correct pay to pass multiple XML documents to any XSL file via javax.xml.transform API ?

Update

Still stuck with the issue ,can any one let me how can i pass XML object into a XSLT 2.0 stylesheet as a param . I have tried different approaches but no luck still . I need to know a way out via JAVA xsl transform API .

Answer 1

I think your issue is in the XSLT. Change

<xsl:variable name="lookup" select="('documentFile')/>  . 

to

<xsl:variable name="lookup" select="document('lookup')/>

this will cause the transformer to make the DOM of your document accessible in the variable lookup. The key lookup comes from docs.put("lookup", documentFile);

Dynamically Pass Multiple XML Sources to XSL Transformation via URIResolver.

Full Working Example:

Be there three XML files: repo.xml, books.xml and articles.xml. The repo.xml contains status information about books and articles. The files articles.xml and books.xml contain title information about each item. The goal is to print status information of all books and articles together with the title information. The entries in all files are connected via id keys.

Find complete example at github or copy/paste the listings below.

repo.xml

<repository>
    <book>
        <id>1</id>
        <status>available</status>
    </book>
    <book>
        <id>2</id>
        <status>lost</status>
    </book>
    <article>
        <id>1</id>
        <status>in transit</status>
    </article>
</repository>

books.xml

<books>
    <book id="1">
        <title>Book One</title>
    </book>
    <book id="2">
        <title>Book Two</title>
    </book>
    <book id="3">
        <title>Book Three</title>
    </book>
</books>

articles.xml

<articles>
    <article id="1">
         <title>Article One</title>
    </article>
    <article id="2">
        <title>Article Two</title>
    </article>
    <article id="3">
        <title>Article Three</title>
    </article>
</articles>

join.xsl

<?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" encoding="UTF-8" indent="yes" />

<xsl:template match="/">
    <titleStatusJoin>
        <xsl:for-each select="//book">
            <xsl:variable name="myId" select="id" />
            <book>
                <status>
                    <xsl:value-of select="status" />
                </status>
                <title>
                    <xsl:for-each select="document('bookFile')//book">
                        <xsl:variable name="bookId" select="@id" />
                        <xsl:choose>
                            <xsl:when test="$myId = $bookId">
                                <xsl:value-of select="title" />
                            </xsl:when>
                        </xsl:choose>
                    </xsl:for-each>
                </title>
            </book>
        </xsl:for-each>
        <xsl:for-each select="//article">
            <xsl:variable name="myId" select="id" />
            <article>
                <status>
                    <xsl:value-of select="status" />
                </status>
                <title>
                    <xsl:for-each select="document('articleFile')//article">
                        <xsl:variable name="bookId" select="@id" />
                        <xsl:choose>
                            <xsl:when test="$myId = $bookId">
                                <xsl:value-of select="title" />
                            </xsl:when>
                        </xsl:choose>
                    </xsl:for-each>
                </title>
            </article>
        </xsl:for-each>

    </titleStatusJoin>
</xsl:template>
</xsl:stylesheet>

Use this Java code...

@Test
public void useMultipleXmlSourcesInOneXsl3() {
    InputStream xml = Thread.currentThread().getContextClassLoader().getResourceAsStream("stack54335576/repo.xml");
    InputStream xsl = Thread.currentThread().getContextClassLoader().getResourceAsStream("stack54335576/join3.xsl");
    InputStream booksXml = Thread.currentThread().getContextClassLoader()
                    .getResourceAsStream("stack54335576/books.xml");
    InputStream articlesXml = Thread.currentThread().getContextClassLoader()
                    .getResourceAsStream("stack54335576/articles.xml");
    Document booksDom = readXml(booksXml);
    Document articlesDom = readXml(articlesXml);
    Map<String, Document> parameters = new HashMap<>();
    parameters.put("bookFile", booksDom);
    parameters.put("articleFile", articlesDom);
    xslt(xml, xsl, parameters);
}

public final void xslt(InputStream xml, InputStream xsl, Map<String, Document> parameters) {
    try {
        TransformerFactory factory = TransformerFactory.newInstance();
        Transformer transformer = factory.newTransformer(new StreamSource(xsl));
        transformer.setURIResolver((href, base) -> new DOMSource(parameters.get(href)));
        transformer.transform(new StreamSource(xml), new StreamResult(System.out));
    } catch (Exception e) {
        throw new RuntimeException(e);
    }
}

private Document readXml(InputStream xmlin) {
    try {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        dbf.setNamespaceAware(true);
        DocumentBuilder db = dbf.newDocumentBuilder();
        return db.parse(xmlin);
    } catch (Exception e) {
        throw new RuntimeException(e);
    }
}

...to produce this output

<?xml version="1.0" encoding="UTF-8"?>
<titleStatusJoin>
   <book>
      <status>available</status>
      <title>Book One</title>
   </book>
   <book>
     <status>lost</status>
     <title>Book Two</title>
   </book>
   <article>
     <status>in transit</status>
     <title>Article One</title>
   </article>
</titleStatusJoin>

Answer 2

Did you already try this ?

org.w3c.dom.Document doc = ... // Your xml document
transformer.setParameter("demo", doc.getDocumentElement());