android利用SAX解析xml(以解析谷歌天气预报xml预报为例)

package com.mars.android;

import java.io.BufferedInputStream;

import java.io.InputStream;

import java.net.URL;

import java.net.URLConnection;

import javax.xml.parsers.SAXParser;

import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.InputSource;

import org.xml.sax.XMLReader;

import android.app.Activity;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.os.Bundle;

import android.util.Log;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.EditText;

import android.widget.ImageView;

import android.widget.TextView;

public class CurrentWeather extends Activity {

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

Button submit=(Button)findViewById(R.id.submit);

submit.setOnClickListener(new OnClickListener(){

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

/*从google上获得图标*/

try{

String city=((EditText)findViewById(R.id.cityname))

.getText().toString().trim();

String querystr="http://www.google.com/ig/api?weather="+city;

URL aURL=new URL(querystr.replace(" ", "%20"));

/*从SAXParserFactory中获取SAXParser*/

Log.v("querystr",querystr);

Log.v("querystr", querystr.replace(" ", "%20"));

/*创建一个SAXParserFactory对象*/

SAXParserFactory spf=SAXParserFactory.newInstance();

/*利用SAXParserFactory对象spf的newSAXParser()方法生成一个SAXParser对象*/

SAXParser sp=spf.newSAXParser();

XMLReader xr=sp.getXMLReader();//从SAXParser中得到XMLReader

/*创建一个解析xml文件的GoogleWeatherHandler对象gwh*/

GoogleWeatherHandler gwh=new GoogleWeatherHandler();

/*设定XMLReader类的xml处理对象*/

xr.setContentHandler(gwh);

/*解析XML文件内容*/

xr.parse(new InputSource(aURL.openStream()));

/*下面进行图片的请求 并生成一幅bmp图像*/

URL iconurl=new URL("http://www.google.com"+gwh.getIconURL());

URLConnection conn= iconurl.openConnection();

conn.connect();

//获得图像的字符流

InputStream is=conn.getInputStream();

BufferedInputStream bis=new BufferedInputStream(is,8192);

ImageView iv=(ImageView)findViewById(R.id.iconofwheather);

Bitmap bm=null;//生成了一张bmp图像

bm=BitmapFactory.decodeStream(bis);

bis.close();

is.close();//关闭流

System.out.println(bm.getHeight());

iv.setImageBitmap(bm);

TextView tv1=(TextView)findViewById(R.id.condition);

tv1.append(gwh.getCurrent_condition());

TextView tv2=(TextView)findViewById(R.id.temperature);

tv2.append(gwh.getCurrent_temp().toString()+"摄氏度");

TextView tv3=(TextView)findViewById(R.id.humidity);

tv3.append(gwh.getCurrent_hum().replace("Humidity", ""));

System.out.println(tv1.getText().toString());

System.out.println(tv2.getText().toString());

System.out.println(tv3.getText().toString());

}

catch(Exception e){

Log.e("error", e.toString());

}

}

});

}

}

上面是一个activity用于显示解析xml得出的内容。下面是一个继承自DefaultHandler的类 专门用于处理XML

package com.mars.android;

import org.xml.sax.Attributes;

import org.xml.sax.SAXException;

import org.xml.sax.helpers.DefaultHandler;

public class GoogleWeatherHandler extends DefaultHandler{

private boolean in_forecast_information = false;

private boolean in_current_conditions = false;

private boolean in_forecast_conditions = false;

private Integer current_temp;

private String current_condition;

private String current_hum;

private String iconURL;

// private String forecast_date;

private boolean usingSITemperature = false; // false为华氏度，true为摄氏度

public Integer getCurrent_temp() {

return current_temp;

}

public void setCurrent_temp(Integer currentTemp) {

current_temp = currentTemp;

}

public String getCurrent_condition() {

return current_condition;

}

public void setCurrent_condition(String currentCondition) {

current_condition = currentCondition;

}

public String getCurrent_hum() {

return current_hum;

}

public void setCurrent_hum(String currentHum) {

current_hum = currentHum;

}

public String getIconURL() {

return iconURL;

}

public void setIconURL(String iconURL) {

this.iconURL = iconURL;

}

@Override

public void characters(char[] ch, int start, int length)

throws SAXException {

}

@Override

public void endDocument() throws SAXException {

}

@Override

public void endElement(String uri, String localName, String qName)

throws SAXException {

// TODO Auto-generated method stub

if (localName.equals("forecast_information")) {

this.in_forecast_information = false;

} else if (localName.equals("current_conditions")) {

this.in_current_conditions = false;

} else if (localName.equals("forecast_conditions")) {

this.in_forecast_conditions = false;

}

}

@Override

public void startDocument() throws SAXException {

// TODO Auto-generated method stub

// super.startDocument();

}

@Override

public void startElement(String uri, String localName, String qName,

Attributes attributes) throws SAXException {

// TODO Auto-generated method stub

if (localName.equals("forecast_information")) {

this.in_forecast_information = true;

} else if (localName.equals("current_conditions")) {

this.in_current_conditions = true;

} else if (localName.equals("forecast_conditions")) {

this.in_forecast_conditions = true;

} else {

String dataAttribute = attributes.getValue("data");

// 'Inner' Tags of "<forecast_information>"

if (localName.equals("city")) {

} else if (localName.equals("postal_code")) {

} else if (localName.equals("latitude_e6")) {

/* One could use this to convert city-name to Lat/Long. */

} else if (localName.equals("longitude_e6")) {

/* One could use this to convert city-name to Lat/Long. */

} else if (localName.equals("forecast_date")) {

} else if (localName.equals("current_date_time")) {

} else if (localName.equals("unit_system")) {

if (dataAttribute.equals("SI"))

this.usingSITemperature = true;

}

// SHARED(!) 'Inner' Tags within "<current_conditions>" AND

// "<forecast_conditions>"

else if (localName.equals("day_of_week")) {

if (this.in_current_conditions) {

//可扩展

} else if (this.in_forecast_conditions) {

//可扩展

}

} else if (localName.equals("icon")) {

if (this.in_current_conditions) {

this.setIconURL(dataAttribute);

} else if (this.in_forecast_conditions) {

//可扩展

}

} else if (localName.equals("condition")) {

if (this.in_current_conditions) {

this.setCurrent_condition(dataAttribute);

} else if (this.in_forecast_conditions) {

//可扩展

}

}

// 'Inner' Tags within "<current_conditions>"

else if (localName.equals("temp_f")) {

//this.setCurrentTemp(Integer.parseInt(dataAttribute));

} else if (localName.equals("temp_c")) {

this.setCurrent_temp(Integer.parseInt(dataAttribute));

} else if (localName.equals("humidity")) {

this.setCurrent_hum(dataAttribute);

} else if (localName.equals("wind_condition")) {

//可扩展

}

// 'Inner' Tags within "<forecast_conditions>"

else if (localName.equals("low")) {

int temp = Integer.parseInt(dataAttribute);

if (this.usingSITemperature) {

//可扩展

} else {

//可扩展

}

} else if (localName.equals("high")) {

//int temp = Integer.parseInt(dataAttribute);

if (this.usingSITemperature) {

//可扩展

} else {

//可扩展

}

}

}

}

}

另外 需要在Manifest.xml中加入INTERNET权限

在application节点后加上<uses-permission android:name="android.permission.INTERNET" />