Android开发WeatherForecast程序

原创

Android小子 2012-02-03 12:20:00 ©著作权

文章标签 移动开发 android开发 WeatherForecast 文章分类 Android 移动开发

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1，使用Googel API
http:///ig/api?&weather=beijing

2，使用DOM解析XML

String weather = "";     String url = "[url=http:///ig/api?&weather=beijing]http:///ig/api?&weather=beijing[/url]";     DefaultHttpClient client = new DefaultHttpClient();     HttpUriRequest req = new HttpGet(url);     HttpResponse resp = client.execute(req);     HttpEntity ent = resp.getEntity();     InputStream stream = ent.getContent();     DocumentBuilder b = DocumentBuilderFactory.newInstance().newDocumentBuilder();     Document d = b.parse(new InputSource(stream));     NodeList n = d.getElementsByTagName("forecast_conditions");     for (int i = 0; i < n.getLength(); i++) {     weather += n.item(i).getChildNodes().item(0).getAttributes().item(0).getNodeValue();     weather += ", ";     weather += (Integer.parseInt(n.item(i).getChildNodes().item(1).getAttributes().item(0).getNodeValue()) - 32) * 5 / 9;     weather += " ~ ";     weather += (Integer.parseInt(n.item(i).getChildNodes()             .item(2).getAttributes().item(0).getNodeValue()) - 32) * 5 / 9;     weather += ", ";     weather += n.item(i).getChildNodes().item(4).getAttributes().item(0).getNodeValue();     weather += "\n";     }

3，另起Thread处理Web请求

new Thread() {     public void run() {     try {      // ...     } catch (Exception e) {      e.printStackTrace();     }   }     }.start();

4，使用Handler传递Thread处理结果到UI主Thread

h = new Handler() {     public void handleMessage(Message msg) {       tv.setText((String)msg.obj);  }  };     new Thread() {     // ...  Message msg = h.obtainMessage(1, 1, 1, weather);  h.sendMessage(msg);     }

5，完整代码

package com.hideto.weatherforecast;     import java.io.InputStream;  import javax.xml.parsers.DocumentBuilder;  import javax.xml.parsers.DocumentBuilderFactory;  import org.apache.http.HttpEntity;  import org.apache.http.HttpResponse;  import org.apache.http.client.methods.HttpGet;  import org.apache.http.client.methods.HttpUriRequest;  import org.apache.http.impl.client.DefaultHttpClient;  import org.w3c.dom.Document;  import org.w3c.dom.NodeList;  import org.xml.sax.InputSource;  import .Activity;  import android.os.Bundle;  import android.os.Handler;  import android.os.Message;  import android.widget.TextView;     public class WeatherForecast extends Activity {     public TextView tv;  public Handler h;  @Override     public void onCreate(Bundle savedInstanceState) {       super.onCreate(savedInstanceState);       tv = new TextView(this);    tv.setText("Loading...");    setContentView(tv);    h = new Handler() {     public void handleMessage(Message msg) {      tv.setText((String)msg.obj);        }    };       new Thread() {     public void run() {         try {          String weather = "";       String url = "[url=http:///ig/api?&weather=beijing]http:///ig/api?&weather=beijing[/url]";          DefaultHttpClient client = new DefaultHttpClient();       HttpUriRequest req = new HttpGet(url);       HttpResponse resp = client.execute(req);       HttpEntity ent = resp.getEntity();  
     InputStream stream = ent.getContent();       DocumentBuilder b = DocumentBuilderFactory.newInstance().newDocumentBuilder();       Document d = b.parse(new InputSource(stream));       NodeList n = d.getElementsByTagName("forecast_conditions");          for (int i = 0; i < n.getLength(); i++) {           weather += n.item(i).getChildNodes().item(0).getAttributes().item(0).getNodeValue();           weather += ", ";           weather += (Integer.parseInt(n.item(i).getChildNodes().item(1).getAttributes().item(0).getNodeValue()) - 32) * 5 / 9;           weather += " ~ ";           weather += (Integer.parseInt(n.item(i).getChildNodes().item(2).getAttributes().item(0).getNodeValue()) - 32) * 5 / 9;           weather += ", ";           weather += n.item(i).getChildNodes().item(4).getAttributes().item(0).getNodeValue();        weather += "\n";        }          Message msg = h.obtainMessage(1, 1, 1, weather);       h.sendMessage(msg);         } catch (Exception e) {       e.printStackTrace();         }      }     }.start();   }  }

6，修改AndroidManifest.xml加上INTERNET访问权限

<?xml version="1.0" encoding="utf-8"?>     <manifest xmlns:android="[url=http:///apk/res/android]http:///apk/res/android[/url]"         package="com.hideto.weatherforecast"         android:versionCode="1"         android:versionName="1.0.0">         <uses-permission android:name="android.permission.INTERNET"></uses-permission>       <application android:icon="@drawable/icon" android:label="@string/app_name">         <activity android:name=".WeatherForecast"                     android:label="@string/app_name">               <intent-filter>                  <action android:name="android.intent.action.MAIN" />                   <category android:name="android.intent.category.LAUNCHER" />               </intent-filter>           </activity>       </application>   </manifest>