使用dom4j操作xml文件可以参考dom4j的api文档。
1、parsing XML 解析xml文件
SAXReader reader = new SAXReader(); File file =new File("xx.xml"); Document document = reader.read(file);
2、获取根元素
Element root = document.getRootElement();
3、获取所有的元素、获取某个特定的元素、获取根元素的属性
// iterate through child elements of root for ( Iterator i = root.elementIterator(); i.hasNext(); ) { Element element = (Element) i.next(); // do something } // iterate through child elements of root with element name "foo" for ( Iterator i = root.elementIterator( "foo" ); i.hasNext(); ) { Element foo = (Element) i.next(); // do something } // iterate through attributes of root for ( Iterator i = root.attributeIterator(); i.hasNext(); ) { Attribute attribute = (Attribute) i.next(); // do something }
4、将document写入文件
//prepare an output format,which has new line .打印(显示)出来有格式 OutputFormat format = OutputFormat.createPrettyPrint(); format.setIndentSize(4); // OutputStream os = new FileOutputStream(fileName); //output stream ( where to output )and format (how to output) XMLWriter writer = new XMLWriter(os,format); //output content( what to be output)---document writer.write(document); writer.close();
使用例子
1、在xml文件中增加element
步骤:1、open the document and get the rootDocument;
2、construct an element ;
3、append the newly element to the root element;
4、update the count of the root element;此处是更新根元素的count属性,如果没有这个属性则不需要更新,count属性存储element 的个数。
5、save the document into the file.