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(textCreatetime);
          eLastUseTime.appendChild(textLastUseTime);
          //通过Name获取节点    第0个节点
          eModel.appendChild(eInstructions);
          eModel.appendChild(eCreatetime);
          eModel.appendChild(eLastUseTime);
          Node book = doc.getElementsByTagName("instructionsList").item(0);
          book.appendChild(eModel);
          //添加一个属性
          //Attr attr = doc.createAttribute("aaa");
          //创建工厂对象
          TransformerFactory tfs = TransformerFactory.newInstance();
          //创建Transformer对象
          Transformer tf = tfs.newTransformer();
          //将document输出到输出流中。
          tf.transform(new DOMSource(doc),new StreamResult(new FileOutputStream(fu.getSDCardRoot() + File.separator + filePath
                    + File.separator +"bb.xml")));
          Long hastime=System.currentTimeMillis()-st;
          Log.i(TAG, "DOM方式耗时："+hastime);
    }

使用PULL的方式

       网上查了很久，好像大家一致认为PULL只能够解析XML，不能够对XML文件进行修改操作

      所以我想了一种非常麻烦的修改方法

1.解析原XML文件，得到数据集合

2.将新数据插入到集合中去

3.重新生成XML

代码如下

       1.解析XML文件

/**
     * 获取XML中所有的指令信息
     *
     * @param inputStream
     * @return
     * @throws XmlPullParserException
     * @throws IOException
     */
    private List<Instructions> parseDateSource(InputStream inputStream)
            throws XmlPullParserException, IOException {
        Long st=System.currentTimeMillis();
        List<Instructions> instructionsList = null;
        Instructions instructionsModel = null;
        XmlPullParser parse = Xml.newPullParser();
        parse.setInput(inputStream, "utf-8");
        int event = parse.getEventType();
        while (event != XmlPullParser.END_DOCUMENT) {
            switch (event) {
            case XmlPullParser.START_DOCUMENT:
                instructionsList = new ArrayList<Instructions>();// 初始化指令集合
                break;
            case XmlPullParser.START_TAG:
                if (parse.getName().equals("instructionsModel")) {
                    instructionsModel = new Instructions();
                }
                if (instructionsModel != null) {
                    if (parse.getName().equals("instructions")) {
                        instructionsModel.setInstructions(parse.nextText());
                    } else if (parse.getName().equals("createtime")) {
                        instructionsModel.setCreateTime(parse.nextText());
                    } else if (parse.getName().equals("lastusetime")) {
                        instructionsModel.setLastUseTime(parse.nextText());
                    }
                }
                break;
            case XmlPullParser.END_TAG:
                if (parse.getName().equals("instructionsModel")) {
                    instructionsList.add(instructionsModel);
                    instructionsModel = null;
                }
                break;
            default:
                break;
            }
            event = parse.next();// 进入到下一个元素并触发相应事件
        }
         Long hastime=System.currentTimeMillis()-st;
          Log.i(TAG, "PULL方式解析耗时："+hastime);
        return instructionsList;
    }

       2.将数据插入到集合

/**
 * 将新指令添加到XML文件中
 * @param out
 * @param inputStream
 * @param instructions2
 * @throws IllegalStateException
 * @throws IllegalArgumentException
 * @throws XmlPullParserException
 * @throws IOException
 */
private void append2xml(OutputStream out, List<Instructions> instructionsList,
        Instructions instructions2) throws IllegalArgumentException, IllegalStateException, IOException, XmlPullParserException
         {
    //避免重复记录指令的操作
        for(int i=0;i<instructionsList.size();i++){
            Instructions instructions=instructionsList.get(i);
            if(instructions.getInstructions().equals(instructions2.getInstructions())){
                instructionsList.remove(i);
                instructions2.setCreateTime(instructions.getCreateTime());
                break;
            }
        }
        instructionsList.add(0, instructions2);
        createInstructionXml(out, instructionsList);
}

3.生成新的XML文件的方法

/***
     * 根据列表生成XML文件
     * @param out
     * @param instructionsList
     * @throws IllegalArgumentException
     * @throws IllegalStateException
     * @throws IOException
     */
    private void createInstructionXml(OutputStream out,
            List<Instructions> instructionsList)
            throws IllegalArgumentException, IllegalStateException, IOException {
        // TODO Auto-generated method stub
        XmlSerializer serializer = Xml.newSerializer();
        // 设置文件编码
        serializer.setOutput(out, "UTF-8");
        serializer.startDocument("UTF-8", true);
        serializer.startTag(null, "instructionsList");
        for (Instructions instructions : instructionsList) {
            serializer.startTag(null, "instructionsModel");
            serializer.startTag(null, "instructions");
            serializer.text(instructions.getInstructions());
            serializer.endTag(null, "instructions");
            serializer.startTag(null, "createtime");
            serializer.text(instructions.getCreateTime());
            serializer.endTag(null, "createtime");
            serializer.startTag(null, "lastusetime");
            serializer.text(instructions.getLastUseTime());
            serializer.endTag(null, "lastusetime");
            serializer.endTag(null, "instructionsModel");
        }
        serializer.endTag(null, "instructionsList");
        serializer.endDocument();
        out.flush();
        out.close();
    }