2

我们使用 SAX 来解析 XML，因为它不需要将整个 XML 文档读入内存来解析单个值。我阅读了许多坚持 SAX 只能用于解析/解码 XML 而不能创建它的文章。这是真的？

4

2 回答 2

4

不，这不是真的，您可以使用类似于以下内容的方式将 XML 编码为 Java 中的任何 Writer：

char[] ch;
AttributesImpl atts = new AttributesImpl();
Writer writer = new StringWriter();
StreamResult streamResult = new StreamResult(writer);
SAXTransformerFactory tf = (SAXTransformerFactory) TransformerFactory.newInstance();

// SAX2.0 ContentHandler
TransformerHandler transformerHandler = tf.newTransformerHandler();

Transformer serializer = transformerHandler.getTransformer();

serializer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
// serializer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, "nodes.dtd");
serializer.setOutputProperty(OutputKeys.INDENT, "yes");

transformerHandler.setResult(streamResult);

transformerHandler.startDocument();

atts.clear();
// atts.addAttribute("", "", "xmlns", "CDATA", "http://www.example.com/nodes");
// atts.addAttribute("", "", "xmlns:xsi", "CDATA", "http://www.w3.org/2001/XMLSchema-instance");
// atts.addAttribute("", "", "xsi:schemaLocation", "CDATA", "/nodes.xsd");
transformerHandler.startElement("", "", "node_list", atts);

// displayName element
if (displayName != null) {
    transformerHandler.startElement("", "", "display_name", null);
    ch = displayName.toCharArray();
    transformerHandler.characters(ch, 0, ch.length);
    transformerHandler.endElement("", "", "display_name");
}

// nodes element
transformerHandler.startElement("", "", "nodes", null);

atts.clear();
atts.addAttribute("", "", "node_type", "CDATA", "sometype");
transformerHandler.startElement("", "", "node", atts);

ch = node.getValue().toCharArray();
transformerHandler.startElement("", "", "value", null);
transformerHandler.characters(ch, 0, ch.length);
transformerHandler.endElement("", "", "value");

transformerHandler.endElement("", "", "node");

transformerHandler.endElement("", "", "nodes");

transformerHandler.endElement("", "", "node_list");

transformerHandler.endDocument();

String xml = writer.toString();
于 2008-09-16T15:20:20.370 回答
0

SAX 处理程序接口被设计为易于实现。很容易编写一个类似的类（可能包装一个 SAX 接口）以使其易于调用 - 链接、记住要关闭的元素、更简单的属性等。

于 2008-09-16T16:00:39.993 回答