浅析XML字符串和XML DOCUMENT的相互转换

　　一、使用最原始的javax.xml.parsers，标准的jdk api

// 字符串转XML
String xmlStr = /"....../";
StringReader sr = new StringReader(xmlStr);
InputSource is = new InputSource(sr);
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder=factory.newDocumentBuilder();
Document doc = builder.parse(is);

//XML转字符串
TransformerFactory tf = TransformerFactory.newInstance();
Transformer t = tf.newTransformer();
t.setOutputProperty(/"encoding/",/"GB23121/");//解决中文问题，试过用GBK不行
ByteArrayOutputStream bos = new ByteArrayOutputStream();
t.transform(new DOMSource(doc), new StreamResult(bos));
String xmlStr = bos.toString();

这里的XML DOCUMENT为org.w3c.dom.Document

　　二、使用dom4j后程序变得更简单

// 字符串转XML
String xmlStr = /"....../";
Document document = DocumentHelper.parseText(xmlStr);

// XML转字符串
Document document = ...;
String text = document.asXML();

这里的XML DOCUMENT为org.dom4j.Document

　　三、使用JDOM

JDOM的处理方式和第一种方法处理非常类似

//字符串转XML
String xmlStr = /"...../";
StringReader sr = new StringReader(xmlStr);
InputSource is = new InputSource(sr);
Document doc = (new SAXBuilder()).build(is);

//XML转字符串
Format format = Format.getPrettyFormat();
format.setEncoding(/"gb2312/");//设置xml文件的字符为gb2312，解决中文问题
XMLOutputter xmlout = new XMLOutputter(format);
ByteArrayOutputStream bo = new ByteArrayOutputStream();
xmlout.output(doc,bo);
String xmlStr = bo.toString();

这里的XML DOCUMENT为org.jdom.Document

　　四、JAVASCRIPT中的处理

//字符串转XML
var xmlStr = /"...../";
var xmlDoc = new ActiveXObject(/"Microsoft.XMLDOM/");
xmlDoc.async=false;
xmlDoc.loadXML(xmlStr);
//可以处理这个xmlDoc了
var name = xmlDoc.selectSingleNode(/"/person/name/");
alert(name.text);

//XML转字符串
var xmlDoc = ......;
var xmlStr = xmlDoc.xml

这里的XML DOCUMENT为javascript版的XMLDOM