pull解析过程

解析xml文件；
1先写一篇xml文件；

try {
            FileOutputStream fos = new FileOutputStream("/sdcard/a.xml");
            XmlSerializer s = Xml.newSerializer();
            s.setOutput(fos, "utf-8");
            s.startDocument("utf-8", true);
            s.startTag(null, "email").attribute(null, "date", "2016,5,8")
                    .attribute(null, "time", "15:30");
            s.startTag(null, "from").text("張三").endTag(null, "from")
                    .startTag(null, "toemail").text("李四")
                    .endTag(null, "toemail").startTag(null, "toemail")
                    .text("王五").endTag(null, "toemail");
            s.startTag(null, "title").text("xml pull test")
                    .endTag(null, "title");
            s.endTag(null, "email");
            s.flush();
            fos.close();
            Toast.makeText(MainActivity.this, "生成成功", 5000).show();
        } catch (Exception e) {
            Toast.makeText(MainActivity.this, "写入失败", Toast.LENGTH_SHORT)
                    .show();
            e.printStackTrace();
        }

读取这篇xml文件；

try {

            FileInputStream fis = new FileInputStream("/sdcard/a.xml");
            XmlPullParser parser = Xml.newPullParser();
            tv.setText("");
            parser.setInput(fis, "utf-8");
            int type;
            while ((type = parser.next()) != XmlPullParser.END_DOCUMENT) {
                String name = parser.getName();
                if (type == XmlPullParser.START_TAG) {
                    if (name.equals("email")) {
                        String date = parser.getAttributeValue(null, "date");
                        String time = parser.getAttributeValue(null, "time");
                        tv.append("\n日期:" + date);
                        tv.append("\n时间" + time);
                    } else if (name.equals("from")) {
                        tv.append("\n发件人：" + parser.nextText());

                    } else if (name.equals("toemail")) {
                        tv.append("\n收件人" + parser.nextText());
                    } else if (name.equals("title")) {
                        tv.append("\n标题：" + parser.nextText());
                    }

                }

            }

            Toast.makeText(this, "读取成功了", Toast.LENGTH_LONG);

        } catch (Exception e) {
            Toast.makeText(MainActivity.this, "读取失败", Toast.LENGTH_SHORT)
                    .show();
            e.printStackTrace();
        }