php&java（三）

做为第二个例子，我们使用了Xalan-java的XSLT引擎，这个引擎来自于APACHE的XML项目，使用这个程序，我们能够使用XSL转换XML源文件。这将极大的方便我们处理文档和进行内容管理。

开始之前，我们需要将xerces.jar 和 xalan.jar文件放入java.class.path目录下（这两个文件包含在Xalan-Java 1.2 中，可以从xml.apache.org处下载）。
PHP程序如下：
函数xslt_transform()以XML和XSL文件为参数，形式可为文件名（如:foo.xml）或URL（如：http://localhost/foo.xml）。

<?php

function xslt_transform($xml,$xsl) {

  // Create a XSLTProcessorFactory object. XSLTProcessorfactory is a Java
  // class which manufactures the processor for performing transformations.
  $XSLTProcessorFactory = new java(“org.apache.xalan.xslt.XSLTProcessorFactory”);

  // Use the XSLTProcessorFactory method getProcessor() to create a
  // new XSLTProcessor object.
  $XSLTProcessor = $XSLTProcessorFactory->getProcessor();

  // Use XSLTInputSource objects to provide input to the XSLTProcessor
  // process() method for transformation. Create objects for both the
  // xml source as well as the XSL input source. Parameter of
  // XSLTInputSource is (in this case) a ‘system identifier’ (URI) which
  // can be an URL or filename. If the system identifier is an URL, it
  // must be fully resolved.
  $xmlID = new java(“org.apache.xalan.xslt.XSLTInputSource”, $xml);
  $stylesheetID = new java(“org.apache.xalan.xslt.XSLTInputSource”, $xsl);

  // Create a stringWriter object for the output.
  $stringWriter = new java(“java.io.StringWriter”);

  // Create a ResultTarget object for the output with the XSLTResultTarget
  // class. Parameter of XSLTResultTarget is (in this case) a ‘character
  // stream’, which is the stringWriter object.  
  $resultTarget = new java(“org.apache.xalan.xslt.XSLTResultTarget”, $stringWriter);

  // Process input with the XSLTProcessors’ method process(). This
  // method uses the XSL stylesheet to transform the XML input, plac来源gaodaimacom搞#代%码网ing
  // the result in the result target.
  $XSLTProcessor->process($xmlID,$stylesheetID,$resultTarget);

  // Use the stringWriters’ method toString() to
  // return the buffer’s current value as a string to get the
  // transformed result.
  $result = $stringWriter->toString();
  $stringWriter->close();
  return($result);
}

?>

函数定义好后，我们就可以调用它了，在下面的例程中，变量$xml指向一个URL字符串，$xsl也是如此。这个例子将显示5个最新的phpbuilder.com文章标题。

<?php

$xml = “http://www.phpbuilder.com/rss_feed.php?type=articles&limit=5&#8221;;
$xsl = “http://www.soeterbroek.com/code/xml/rss_html.xsl&#8221;;
$out = xslt_transform($xml,$xsl);
echo $out;

?>

如果你在本地机上运行程序，必须确保你的函数参数指向正确的文件名。

<?php

$xml  = “/web/htdocs/xml_java/rss_feed.xml”;
$xsl  = “/web/htdocs/xml_java/rss_html.xsl”;
$out = xslt_transform($xml,$xsl);
echo $out;

?>

虽然这种效果我们可以通过其它方法实现，或许那些方法更好，但这个例子能让你对PHP调用JAVA类有一个更好的了解。

教程结束了，希望你能够从这篇教程中学到点东西，以下是一些你用得到的链接：
http://www.php4win.de ~ A great Win32 distribution of PHP
http://www.javasoft.com ~ Sun’s Java release
http://www.jars.com ~ Start searching for handy Java classes
http://www.gamelan.com ~ More Java classes
http://www.technetcast.com/tnc_play_stream.html?stream_id=400 ~ Sam Ruby about PHP and Java integration at Open Source Convention 2000 (audio)
http://xml.apache.org ~ Apache XML Project
http://www.phpbuilder.com/columns/justin20001025.php3 ~ Transforming XML with XSL using Sablotron