Android修改XML文件

最近在项目中需要使用XML记录数据，网上这方面的文章较少，记录一下

使用DOM方式

/**
	 * 追加内容到XML文档
	 * @param instructions
	 * @throws ParserConfigurationException
	 * @throws SAXException
	 * @throws IOException
	 * @throws TransformerException
	 */
	public void append2XML(String instructions) throws ParserConfigurationException, SAXException, IOException, TransformerException{
		Long st=System.currentTimeMillis();
		String time=DateUtils.getCurrLongTime(); 
		DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
		  //通过实例构建DocumentBuilder
		  DocumentBuilder db = dbf.newDocumentBuilder();
		  //创建Document    解析给定的文件
		  Document doc = db.parse(getInputStream());
		  //doc = db.newDocument();
		  //添加一个元素
		  Element eModel = doc.createElement("instructionsModel");
		  Element eInstructions = doc.createElement("instructions");
		  Element eCreatetime = doc.createElement("createtime");
		  Element eLastUseTime = doc.createElement("lastusetime");
		  //在元素中添加文本
		  Text textInstructions = doc.createTextNode(instructions);
		  Text textCreatetime = doc.createTextNode(time);
		  Text textLastUseTime = doc.createTextNode(time);
		  eInstructions.appendChild(textInstructions);
		  eCreatetime.appendChild(textCreatetim