Android -- 创建XML文件对象及其序列化， pull解析XML文件
1. 创建XML文件对象及其序列化
示例代码：（模拟以xml格式备份短信到SD卡）
SmsInfo.java， bean对象
/**
* 短信的业务bean
* @author Administrator
*
*/
public class SmsInfo {
private String body;
private String number;
private int type;
private long id;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public SmsInfo() {
}
public SmsInfo(String body, String number, int type,long id) {
this.body = body;
this.number = number;
this.type = type;
this.id = id;
}
public String getBody() {
return body;
}
public void setBody(String body) {
this.body = body;
}
public String getNumber() {
return number;
}
public void setNumber(String number) {
this.number = number;
}
public int getType() {
return type;
}
public void setType(int type) {
this.type = type;
}
}
SmsUtils.java 工具类
public class SmsUtils {
/**
* 短信备份的工具方法
* @param file 短信备份到哪个文件里面
* @param smsInfos 要备份的短信对象的集合.
*/
public static void backUpSms(File file, List<SmsInfo> smsInfos) throws Exception{
//xml文件的序列号器 帮助生成一个xml文件
FileOutputStream fos = new FileOutputStream(file);
//1.获取到xml的序列号器
XmlSerializer serializer = Xml.newSerializer();
//2.序列化器的初始化
serializer.setOutput(fos, "utf-8"); //文件的编码方式 utf-8
//3.创建xml文件,编码和是否独立，如果独立，一个xml文件 就会包含所有信息
serializer.startDocument("utf-8", true);
serializer.startTag(null, "smss");
//循环的把所有的短信数据都写到 xml文件里面
for(SmsInfo info: smsInfos){
serializer.startTag(null, "sms");
serializer.attribute(null, "id", String.valueOf(info.getId()));
serializer.startTag(null, "body");
serializer.text(info.getBody());
serializer.endTag(null, "body");
serializer.startTag(null, "type");
serializer.text(info.getType()+"");
serializer.endTag(null, "type");
serializer.startTag(null, "number");
serializer.text(info.getNumber());
serializer.endTag(null, "number");
serializer.endTag(null, "sms");
}
serializer.endTag(null, "smss");
serializer.endDocument();
fos.flush();
fos.close();
}
}
MainActivity.java
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
List<SmsInfo> smsInfos = new ArrayList<SmsInfo>();
//模拟创建两个短信数据的对象.
SmsInfo sms1 = new SmsInfo("你好啊 短信1", "5556", 1,9999);
SmsInfo sms2 = new SmsInfo("你好啊 短信2", "5558", 1,8888);
smsInfos.add(sms1);
smsInfos.add(sms2);
File file = new File(Environment.getExternalStorageDirectory(),"back.xml");
try {
SmsUtils.backUpSms(file, smsInfos);
Toast.makeText(this, "备份短信成功", 0).show();
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(this, "备份短信失败", 0).show();
}
}
}
2. pull解析XML文件
示例代码：（模拟解析xml格式的天气情况）
weather.xml 需要解析的XML文件
<?xml version='1.0' encoding='utf-8' standalone='yes' ?> <weather> <day id="1"> <wendu>18</wendu> <wind>5</wind> <type>晴</type> </day> <day id="2"> <wendu>16</wendu> <wind>3</wind> <type>雨</type> </day> </weather>
Weather.java， bean
public class Weather {
private int wendu;
private int wind;
private String type;
private int id;
public int getWendu() {
return wendu;
}
public void setWendu(int wendu) {
this.wendu = wendu;
}
public int getWind() {
return wind;
}
public void setWind(int wind) {
this.wind = wind;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
@Override
public String toString() {
return "天气信息 [温度=" + wendu + ", 风力=" + wind + "级 , 天气状况=" + type
+ ", 未来第=" + id + "天]";
}
}
WeatherService.java，业务类
public class WeatherService {
/**
* 解析获取天气信息
*
* @param is
* 天气信息xml文件对应的流
* @return
* @throws Exception
*/
public static List<Weather> getWeather(InputStream is) throws Exception {
// 解析 天气的xml文件.
// 1.获取到一个xml文件的解析器.
XmlPullParser parser = Xml.newPullParser();
// 2.初始化解析器.
parser.setInput(is, "utf-8");
// 3.解析xml文件.
// 得到当前解析条目的节点类型.
int eventType = parser.getEventType(); // 第一次被调用的时候 定位在xml开头
List<Weather> weatherInfos = null;
Weather weatherInfo = null;
while (eventType != XmlPullParser.END_DOCUMENT) {// 需要 不停的让 解析器解析下一个节点
switch (eventType) {
case XmlPullParser.START_TAG:
if ("weather".equals(parser.getName())) {
// 发现开始节点 为weather 创建集合
weatherInfos = new ArrayList<Weather>();
} else if ("day".equals(parser.getName())) {
// 发现一个新的日期 对应的天气
weatherInfo = new Weather();
String id = parser.getAttributeValue(0);
weatherInfo.setId(Integer.parseInt(id));
} else if ("wendu".equals(parser.getName())) {
String wendu = parser.nextText();
weatherInfo.setWendu(Integer.parseInt(wendu));
} else if ("wind".equals(parser.getName())) {
String wind = parser.nextText();
weatherInfo.setWind(Integer.parseInt(wind));
} else if ("type".equals(parser.getName())) {
String type = parser.nextText();
weatherInfo.setType(type);
}
break;
case XmlPullParser.END_TAG:
if ("day".equals(parser.getName())) {
weatherInfos.add(weatherInfo);
}
break;
}
eventType = parser.next();// 控制解析器 解析下一个节点
}
is.close();
return weatherInfos;
}
}
MainActivity.java
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView tv = (TextView) findViewById(R.id.tv_weather);
try {
StringBuilder sb = new StringBuilder();
List<Weather> weatherinfos = WeatherService.getWeather(getClassLoader().getResourceAsStream("weather.xml"));
for(Weather weather : weatherinfos){
sb.append(weather.toString());
sb.append("\n");
}
tv.setText(sb.toString());
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(this, "解析天气信息失败", 0).show();
}
}
}
