Attribute定义了XML的属性
|
|
Branch为能够包含子节点的节点如XML元素(Element)和文档(Docuemnts)定义了一个公共的行为,
|
|
CDATA 定义了XML CDATA 区域
|
|
CharacterData是一个标识借口,标识基于字符的节点。如CDATA,Comment, Text.
|
|
Comment 定义了XML注释的行为
|
|
定义了XML文档
|
|
DocumentType 定义XML DOCTYPE声明
|
|
Element定义XML 元素
|
|
ElementHandler定义了 Element 对象的处理器
|
|
被
ElementHandler 使用,用于取得当前正在处理的路径层次信息
|
|
Entity定义 XML entity
|
|
Node为所有的dom4j中XML节点定义了多态行为
|
|
NodeFilter 定义了在dom4j节点中产生的一个滤镜或谓词的行为(predicate)
|
|
ProcessingInstruction 定义 XML 处理指令.
|
|
Text 定义XML 文本节点.
|
|
Visitor 用于实现Visitor模式.
|
|
XPath 在分析一个字符串后会提供一个XPath 表达式
|
// 从文件读取XML,输入文件名,返回XML文档
public Document read(String fileName)
throws MalformedURLException, DocumentException {
SAXReader reader =
new SAXReader();
Document document = reader.read(
new File(fileName));
return document;
}
|
public Element getRootElement(Document doc){
return doc.getRootElement();
}
|
// 枚举所有子节点
for ( Iterator i = root.elementIterator(); i.hasNext(); ) {
Element element = (Element) i.next();
// do something
}
// 枚举名称为foo的节点
for ( Iterator i = root.elementIterator(foo); i.hasNext();) {
Element foo = (Element) i.next();
// do something
}
// 枚举属性
for ( Iterator i = root.attributeIterator(); i.hasNext(); ) {
Attribute attribute = (Attribute) i.next();
// do something
}
|
public
void treeWalk() {
treeWalk(getRootElement());
}
public
void treeWalk(Element element) {
for (
int i = 0, size = element.nodeCount(); i < size; i++) {
Node node = element.node(i);
if (node
instanceof Element) {
treeWalk((Element) node);
}
else { // do something....
}
}
}
|
public
class MyVisitor
extends VisitorSupport {
public
void visit(Element element){
System.out.println(element.getName());
}
public
void visit(Attribute attr){
System.out.println(attr.getName());
}
}
调用: root.accept(new MyVisitor())
|
public
void bar(Document document) {
List list = document.selectNodes( //foo/bar );
Node node = document.selectSingleNode(//foo/bar/author);
String name = node.valueOf( @name );
}
|
public
void findLinks(Document document)
throws DocumentException {
List list = document.selectNodes( //a/@href );
for (Iterator iter = list.iterator(); iter.hasNext(); ) {
Attribute attribute = (Attribute) iter.next();
String url = attribute.getValue();
}
}
|
// XML转字符串
Document document = ...;
String text = document.asXML();
// 字符串转XML
String text = <person> <name>James</name> </person>;
Document document = DocumentHelper.parseText(text);
|
public Document styleDocument(
Document document,
String stylesheet
)
throws Exception {
// load the transformer using JAXP
TransformerFactory factory = TransformerFactory.newInstance();
Transformer transformer = factory.newTransformer(
new StreamSource( stylesheet )
);
// now lets style the given document
DocumentSource source =
new DocumentSource( document );
DocumentResult result =
new DocumentResult();
transformer.transform( source, result );
// return the transformed document
Document transformedDoc = result.getDocument();
return transformedDoc;
}
|
public Document createDocument() {
Document document = DocumentHelper.createDocument();
Element root = document.addElement(root);
Element author1 =
root
.addElement(author)
.addAttribute(name, James)
.addAttribute(location, UK)
.addText(James Strachan);
Element author2 =
root
.addElement(author)
.addAttribute(name, Bob)
.addAttribute(location, US)
.addText(Bob McWhirter);
return document;
}
|
FileWriter out =
new FileWriter( foo.xml );
document.write(out);
|
public
void write(Document document)
throws IOException {
// 指定文件
XMLWriter writer =
new XMLWriter(
new FileWriter( output.xml )
);
writer.write( document );
writer.close();
// 美化格式
OutputFormat format = OutputFormat.createPrettyPrint();
writer =
new XMLWriter( System.out, format );
writer.write( document );
// 缩减格式
format = OutputFormat.createCompactFormat();
writer =
new XMLWriter( System.out, format );
writer.write( document );
}
|