如何使用Java 1.4和SAX將任意數據編碼爲XML？

Question

我們使用SAX來解析XML，因爲它不需要將整個XML文檔讀入內存以解析單個值。我閱讀了許多文章，強調SAX只能用於解析/解碼XML，而不能創建它。這是真的？

Answer 1

不，這不是真的，你可以使用類似的東西編碼XML在Java中任何作家：

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(); 

Answer 2

的SAX處理程序接口被設計爲容易實現。編寫一個類似的類（可能包裝一個SAX接口）很容易，以便於調用鏈接，記住要關閉哪個元素，更簡單的屬性等。