Sunday, March 25, 2012

Get description from Yahoo! Weather RSS feed, and display in WebView.

Last exercise "Get weather info from Yahoo! Weather RSS Feed" get information from Yahoo! Weather RSS feed, and display in simple text form. Inside the returned feed, there are elements with Tag Name of "description". The second one is in html coded form.

example:
<description>
<![CDATA[
<img src="http://l.yimg.com/a/i/us/we/52/26.gif"/><br /> <b>Current Conditions:</b><br /> Cloudy, 47 F<BR /> <BR /><b>Forecast:</b><BR /> Sun - Few Showers. High: 57 Low: 47<br /> Mon - Sunny/Wind. High: 53 Low: 30<br /> <br /> <a href="http://us.rd.yahoo.com/dailynews/rss/weather/New_York__NY/*http://weather.yahoo.com/forecast/USNY0996_f.html">Full Forecast at Yahoo! Weather</a><BR/><BR/> (provided by <a href="http://www.weather.com" >The Weather Channel</a>)<br/>
]]>
</description>


This example demonstrate how to retrieve description elements from Yahoo! Weather RSS feed, and display on a WebView.

Get description from Yahoo! Weather RSS feed, and display in WebView.

package com.exercise.AndroidYahooWeatherDOM;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.apache.http.HttpEntity;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebView;
import android.widget.Toast;

public class AndroidYahooWeatherDOMActivity extends Activity {

WebView webView;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//weather = (TextView)findViewById(R.id.weather);
webView = (WebView)findViewById(R.id.webview);

String weatherString = QueryYahooWeather();
Document weatherDoc = convertStringToDocument(weatherString);

String weatherResult = parseWeatherDescription(weatherDoc);
webView.loadData(weatherResult, "text/html", "UTF-8");

}
private String parseWeatherDescription(Document srcDoc){
String weatherDescription="";

NodeList nodeListDescription = srcDoc.getElementsByTagName("description");
if(nodeListDescription.getLength()>=0){
for(int i=0; i<nodeListDescription.getLength(); i++){
weatherDescription += nodeListDescription.item(i).getTextContent()+"<br/>";
}
}else{
weatherDescription = ("No Description!");
}

return weatherDescription;
}

private Document convertStringToDocument(String src){
Document dest = null;

DocumentBuilderFactory dbFactory =
DocumentBuilderFactory.newInstance();
DocumentBuilder parser;

try {
parser = dbFactory.newDocumentBuilder();
dest = parser.parse(new ByteArrayInputStream(src.getBytes()));
} catch (ParserConfigurationException e1) {
e1.printStackTrace();
Toast.makeText(AndroidYahooWeatherDOMActivity.this,
e1.toString(), Toast.LENGTH_LONG).show();
} catch (SAXException e) {
e.printStackTrace();
Toast.makeText(AndroidYahooWeatherDOMActivity.this,
e.toString(), Toast.LENGTH_LONG).show();
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(AndroidYahooWeatherDOMActivity.this,
e.toString(), Toast.LENGTH_LONG).show();
}

return dest;
}

private String QueryYahooWeather(){

String qResult = "";
String queryString = "http://weather.yahooapis.com/forecastrss?w=2459115";

HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(queryString);

try {
HttpEntity httpEntity = httpClient.execute(httpGet).getEntity();

if (httpEntity != null){
InputStream inputStream = httpEntity.getContent();
Reader in = new InputStreamReader(inputStream);
BufferedReader bufferedreader = new BufferedReader(in);
StringBuilder stringBuilder = new StringBuilder();

String stringReadLine = null;

while ((stringReadLine = bufferedreader.readLine()) != null) {
stringBuilder.append(stringReadLine + "\n");
}

qResult = stringBuilder.toString();
}

} catch (ClientProtocolException e) {
e.printStackTrace();
Toast.makeText(AndroidYahooWeatherDOMActivity.this,
e.toString(), Toast.LENGTH_LONG).show();
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(AndroidYahooWeatherDOMActivity.this,
e.toString(), Toast.LENGTH_LONG).show();
}

return qResult;
}
}


Modify main.xml to add a WebView.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello" />

<WebView
android:id="@+id/webview"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />

</LinearLayout>



You have to modify AndroidManifest.xml to grand permission of "android.permission.INTERNET"

Download the files.


Related:
- Search WOEID from http://query.yahooapis.com/.
- Get Google Weather

3 comments:

siri said...

Ites works fine for me...

if internet is not avilable i want

show the toast messge

if(nodeListDescription.getLength()>=0){
for(int i=0; i";
}
}else{
weatherDescription = ("No Description!");
}
in this statement else condtioin

is not working how to show the

toast message without internet

Drilon Zenku said...

nice work eric although i seem to get an error, i sent you the log file from the log cat, since i couldnt seem to find the error

contact me on my email if the logfile didnt arrive

loni_989@hotmail.com

abumazen said...

it doesnt work