java - 如何使用 Javax.xml.transformer API 将 XML 文档传递给 XSL 文件？

Question

我正在使用 javax.xml.transform API 进行 XSL 转换。 API 仅允许一个 XML 文档作为输入来应用如下转换。

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);

此外，可以像下面这样传递简单的字符串参数，没有任何问题，如下所示:

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

但是，我想将 XML 文档作为参数传递给 XSL 文件。我按照其中一个 SO 页面上的建议尝试了以下代码，如下所示:

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));

我设置了 XML 中的标签以接收如下值:

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

但它对我不起作用。任何人都可以通过 javax.xml.transform API 以正确的方式帮助我将多个 XML 文档传递到任何 XSL 文件吗？

更新

问题仍然存在，谁能告诉我如何将 XML 对象作为参数传递到 XSLT 2.0 样式表中。我尝试了不同的方法，但仍然没有运气。我需要知道通过 JAVA xsl 转换 API 的出路。

Answer 1

我认为您的问题出在 XSLT 中。改变

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

到

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

这将导致转换器使您的文档的 DOM 可在变量 lookup 中访问。关键 lookup 来自 docs.put("lookup", documentFile);

通过 URIResolver 将多个 XML 源动态传递到 XSL 转换。

完整工作示例:

存在三个XML文件:repo.xml、books.xml和articles.xml。 repo.xml 包含有关书籍和文章的状态信息。 articles.xml 和 books.xml 文件包含有关每个项目的标题信息。目标是打印所有书籍和文章的状态信息以及标题信息。所有文件中的条目都通过 id 键连接。

在 github 找到完整的例子或复制/粘贴下面的列表。

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>

书籍.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>

文章.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>

加入.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>

使用此 Java 代码...

@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);
    }
}

...产生这个输出

<?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>