Android XML的操作（SAX）
在android平台下操作xml方式有很多种，常见的为SAX(Simple APIfor XML)和DOM(Document Object Model)。
SAX操作xml的特点是当读取xml文件的时候会随时触发事件，通过事件来处理当前读取到的内容。这一点是跟dom有所不同的，dom是全部读取完后在进行操作。
现在这个实例是以SAX进行XML操作的！
这个例子是读取Google的天气预报为例子做成了，使用的XML地址如下：http://www.google.com/ig/api?weather=beijing&hl=zh-cn
通过互联网获取天气的XML代码，然后再通过SAX进行读取：
在例子中只是读取了当前的时时天气，没有对预报的内容进行读取，等以后再完善吧：
首先根据XML文件抽象出一个类来，我获取到的XML代码如下：
<?xml version="1.0" ?>
<xml_api_reply version="1">
<weather module_id="0" tab_id="0" mobile_row="0" mobile_zipped="1"
row="0" section="0">
<forecast_information>
<city data="Beijing, Beijing" />
<postal_code data="beijing" />
<latitude_e6 data="" />
<longitude_e6 data="" />
<forecast_date data="2010-12-27" />
<current_date_time data="2010-12-28 04:00:00 +0000" />
<unit_system data="SI" />
</forecast_information>
<current_conditions>
<condition data="晴" />
<temp_f data="28" />
<temp_c data="-2" />
<humidity data="湿度： 27%" />
<icon data="/ig/images/weather/sunny.gif" />
<wind_condition data="风向： 西北、风速：7 米/秒" />
</current_conditions>
<forecast_conditions>
<day_of_week data="周一" />
<low data="-12" />
<high data="6" />
<icon data="/ig/images/weather/sunny.gif" />
<condition data="晴" />
</forecast_conditions>
<forecast_conditions>
<day_of_week data="周二" />
<low data="-11" />
<high data="1" />
<icon data="/ig/images/weather/sunny.gif" />
<condition data="晴" />
</forecast_conditions>
<forecast_conditions>
<day_of_week data="周三" />
<low data="-11" />
<high data="2" />
<icon data="/ig/images/weather/chance_of_snow.gif" />
<condition data="可能降雪" />
</forecast_conditions>
<forecast_conditions>
<day_of_week data="周四" />
<low data="-13" />
<high data="-2" />
<icon data="/ig/images/weather/sunny.gif" />
<condition data="晴" />
</forecast_conditions>
</weather>
</xml_api_reply>
不同时间可能获取到的不同，但是格式应该是一致的！下面是根据这个抽象出来的类：
package com.SAXXMLReader;
public class NowWeather {
private String condition;
private String temp_f;
private String temp_c;
private String humidity;
private String icon;
private String wind_condition;
public NowWeather() {
}
public void setcondition(String condition) {
this.condition = condition;
}
public void settempf(String temp_f) {
this.temp_f = temp_f;
}
public void settempc(String temp_c) {
this.temp_c = temp_c;
}
public void sethumidity(String humidity) {
this.humidity = humidity;
}
public void seticon(String icon) {
this.icon = icon;
}
public void setwindcondition(String wind_condition) {
this.wind_condition = wind_condition;
}
public String getNowWeather()
{
StringBuilder strBuilder = new StringBuilder();
strBuilder.append(condition+"\n");
strBuilder.append(temp_f+"\n");
strBuilder.append(temp_c+"\n");
strBuilder.append(humidity+"\n");
strBuilder.append(icon+"\n");
strBuilder.append(wind_condition+"\n");
return strBuilder.toString();
}
}
这个类保存的是获取到的数据，形式可能有多种，这个根据个人的习惯进行书写吧。写到这里，因为在SAX中使用的时候需要有一个DefaultHandler类的继承，实现如下：
package com.SAXXMLReader;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import android.util.Log;
public class WeatherHandler extends DefaultHandler {
private final String CURRENT_CONDITIONS = "current_conditions"; // 当前
private final String forecast_conditions = "forecast_conditions"; // 当前
// 实时天气信息
private boolean is_Current_Conditions = false;
// 预报天气信息
private boolean is_Forecast_Conditions = false;
NowWeather nowWeather = new NowWeather();
@Override
public void characters(char[] ch, int start, int length)
throws SAXException {
// TODO Auto-generated method stub
super.characters(ch, start, length);
}
@Override
public void startDocument() throws SAXException {
// TODO Auto-generated method stub
super.startDocument();
}
public WeatherHandler() {
}
@Override
public void startElement(String uri, String localName, String qName,
Attributes attributes) throws SAXException {
// TODO Auto-generated method stub
// super.startElement(uri, localName, qName, attributes);
String dataAttribute = "OK";
// Log.d("WeatherHandler", localName);
if (localName.equals(CURRENT_CONDITIONS)) {
Log.d("WeatherHandler", localName);
is_Current_Conditions = true;
} else if (localName.equals(forecast_conditions)) {
is_Current_Conditions = false;
} else {
dataAttribute = attributes.getValue("data");
if (this.is_Current_Conditions) {
Log.d("WeatherHandler_1", dataAttribute);
// this.nowWeather.setcondition(dataAttribute);
if (localName.equals("condition")) {
this.nowWeather.setcondition(dataAttribute);
} else if (localName.equals("temp_f")) {
this.nowWeather.settempf(dataAttribute);
} else if (localName.equals("temp_c")) {
this.nowWeather.settempc(dataAttribute);
} else if (localName.equals("humidity")) {
this.nowWeather.sethumidity(dataAttribute);
} else if (localName.equals("icon")) {
this.nowWeather.seticon(dataAttribute);
} else if (localName.equals("wind_condition")) {
this.nowWeather.setwindcondition(dataAttribute);
}
} else if (this.is_Forecast_Conditions) {
Log.d("WeatherHandler_1", dataAttribute);
}
}
// Log.d("WeatherHandler_1", dataAttribute);
}
public String getNowWeather() {
return nowWeather.getNowWeather();
}
@Override
public void endDocument() throws SAXException {
// TODO Auto-generated method stub
super.endDocument();
}
@Override
public void endElement(String uri, String localName, String name)
throws SAXException {
}
}
在这里实现了读取XML代码，并且保存到抽象出来的类中，以供调用。下面的方法是对这个类的调用，通过调用，获取内容：
SAXParserFactory faction =SAXParserFactory.newInstance();
SAXParser parser = faction.newSAXParser();
WeatherHandler handler = new WeatherHandler();
XMLReader reader = parser.getXMLReader();
reader.setContentHandler(handler);
URL url = new URL(SRC);
HttpURLConnection httpconn = (HttpURLConnection) url.openConnection();
//httpconn.getInputStream();
InputStream inStream =httpconn.getInputStream();// this.getResources().openRawResource(R.xml.weather);
InputStreamReader isReader = new InputStreamReader(inStream,"GBK");
//BufferedReader buffRreader = new BufferedReader(isReader);
//String line="";
//String data = "";
//
//while((line=buffRreader.readLine())!=null)
// data += line;
//text1.setText(data);
//Toast.makeText(this,data, Toast.LENGTH_LONG).show();
InputSource inputSource = new InputSource(isReader);
reader.parse(inputSource);
text1.setText(handler.getNowWeather());
//Toast.makeText(this, handler.getNowWeather(), Toast.LENGTH_LONG).show();
这里直接通过获取网上的XML进行的解析，当然你也可以读取本地的XML文件进行解析，这个是一样的。因为有事情，这个写的包括一些方法的命名可能不是怎么规则，还请多多谅解。
如果代码中有什么错误，欢迎指正！