从HTTP-RPC 7.4开始，TemplateEncoder类可用于使用类似于Mustache的轻量级语法来转换XML。
尽管XSLT是将XML文档转换为备用表示形式的强大而灵活的方法，但在实践中通常很难且不便使用。XSLT规范又大又复杂，并且平台支持不一致。
从HTTP-RPC 7.4开始，TemplateEncoder该类可用于使用类似于Mustache的轻量级语法来转换XML 。新ElementAdapter类Element通过Map接口提供对XML DOM内容的访问。该地图的内容可以通过模板文档轻松转换为其他表示形式。
例如，来自W3 Schools的本教程使用XML来建模一个简单的早餐菜单：
<breakfast_menu> Belgian Waffles $5.95 Two of our famous Belgian Waffles with plenty of real maple syrup 650
<food>
<name>Strawberry Belgian Waffles</name>
<price>$7.95</price>
<description>Light Belgian waffles covered with strawberries and whipped cream</description>
<calories>900</calories>
</food>
<food>
<name>Berry-Berry Belgian Waffles</name>
<price>$8.95</price>
<description>Light Belgian waffles covered with an assortment of fresh berries and whipped cream</description>
<calories>900</calories>
</food>
<food>
<name>French Toast</name>
<price>$4.50</price>
<description>Thick slices made from our homemade sourdough bread</description>
<calories>600</calories>
</food>
<food>
<name>Homestyle Breakfast</name>
<price>$6.95</price>
<description>Two eggs, bacon or sausage, toast, and our ever-popular hash browns</description>
<calories>950</calories>
</food>
</breakfast_menu>
该示例使用以下XSLT模板将标记转换为HTML。即使在这个相当简单的示例中，XSLT的冗长也是显而易见的，并且对可读性具有负面影响：
<?xml version="1.0" encoding="UTF-8"?>
<html xsl:version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<body style="font-family:Arial;font-size:12pt;background-color:#EEEEEE">
<xsl:for-each select="breakfast_menu/food">
<div style="background-color:teal;color:white;padding:4px">
<span style="font-weight:bold"><xsl:value-of select="name"/> - </span>
<xsl:value-of select="price"/>
</div>
<div style="margin-left:20px;margin-bottom:1em;font-size:10pt">
<p>
<xsl:value-of select="description"/>
<span style="font-style:italic"> (<xsl:value-of select="calories"/> calories per serving)</span>
</p>
</div>
</xsl:for-each>
</body>
</html>
本javax.xml.transform.Transformer类可用于应用的模板XML文档：
Source source = new StreamSource(getClass().getResourceAsStream("breakfast_menu.xslt"));
Transformer transformer = TransformerFactory.newInstance().newTransformer(source);
Source xmlSource = new StreamSource(getClass().getResourceAsStream("breakfast_menu.xml"));
File homeDirectory = new File(System.getProperty("user.home"));
File outputFile = new File(homeDirectory, "breakfast_menu_1.html");
try (FileOutputStream outputStream = new FileOutputStream(outputFile)) {
transformer.transform(xmlSource, new StreamResult(outputStream));
}
转换的结果如下所示：
以下是如何使用Mustache样式语法定义相似模板的示例。它比以前的版本更简单易读，并且可以使用任何支持HTML的文本编辑器进行编辑：
<!-- Breakfast Menu -->
<html>
<body style="font-family:Arial;font-size:12pt;background-color:#EEEEEE">
<!-- {{#food*}} -->
<div style="background-color:teal;color:white;padding:4px">
<span style="font-weight:bold">{{name}} - </span>
{{price}}
</div>
<div style="margin-left:20px;margin-bottom:1em;font-size:10pt">
<p>
{{description}}
<span style="font-style:italic"> ({{calories}} calories per serving)</span>
</p>
</div>
<!-- {{/food*}} -->
</body>
</html>
此代码使用以下命令将模板应用于XML文档TemplateEncoder：
DocumentBuilder documentBuilder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document document;
try (InputStream inputStream = getClass().getResourceAsStream("breakfast_menu.xml")) {
document = documentBuilder.parse(inputStream);
}
TemplateEncoder templateEncoder = new TemplateEncoder(getClass().getResource("breakfast_menu.html"));
File homeDirectory = new File(System.getProperty("user.home"));
File outputFile = new File(homeDirectory, "breakfast_menu_2.html");
try (FileOutputStream outputStream = new FileOutputStream(outputFile)) {
templateEncoder.write(new ElementAdapter(document.getDocumentElement()), outputStream);
}
结果与XSLT版本相同：
简单并不是胡子风格方法的唯一优势。平均而言，XSLTTransformer版本运行大约需要350毫秒，而运行XSLT的版本大约需要30毫秒TemplateEncoder，相差10倍。
有关HTTP-RPCTemplateEncoder和的更多信息ElementAdapter，请参见项目README。
