getting data from the web

Lex · by **Lex** » Thu Dec 20, 2007 2:28 pm

Hi, I'm trying to get data from a web page, I tried the following code but its not working (its compiling but I get an empty screen when I launch the activity );

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package com.google.android.Test;
 
import java.io.InputStream;
 
import java.net.HttpURLConnection;
 
import java.net.URL;
 
import android.app.Activity;
 
import android.os.Bundle;
 
import android.widget.TextView;
 
public class webCheck extends Activity 
 
{
 
        private TextView vText;
 
        @Override
 
        public void onCreate(Bundle icicle)
 
        {
 
                super.onCreate(icicle);
 
                setContentView(R.layout.webCheck);
 
                vText = (TextView) findViewById(R.id.text1);
 
                try{
 
            URL url = new URL("http://localhost/lab/get.php");
 
            HttpURLConnection http =(HttpURLConnection)url.openConnection();
 
            http.setRequestMethod("GET");
 
            http.connect();
 
            InputStream in = http.getInputStream();
 
            byte by[] = new byte[1024];
 
            in.read(by);
 
            String myString = new String();
 
            myString = in.toString();
 
            in.close();
 
            http.disconnect();
 
            vText.setText(myString);
 
        }
 
                catch(Exception e)
 
                {
 
        } 
 
        }
 
}
 
Parsed in 0.034 seconds,  using GeSHi 1.0.8.4

Whats wrong with my code ? How would u do that ?
Thanks

plusminus · by **plusminus** » Thu Dec 20, 2007 3:49 pm

Hello Lex,

the toString()-method does not return the data it read :!:

Instead use the following code:

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// Replace:
myString = in.toString();
// With:
myString = new String(by);
Parsed in 0.031 seconds,  using GeSHi 1.0.8.4

Should be working now.

Regards,
plusminus

Lex · by **Lex** » Fri Dec 21, 2007 11:31 am

Thanks but it still doesn't work : it compiles and runs, but nothing shows up.

Danuubz · by **Danuubz** » Fri Dec 21, 2007 1:19 pm

I've just tried to implement a code example from O'Reillys 'Java Network Programming' book, but the URLConnection routine doesn't work. Simply the white screen as you already described and the 'not responding' message few seconds after....

plusminus · by **plusminus** » Fri Dec 21, 2007 5:05 pm

Hey guys,

I used the following Code to load an image from the web, for the :src: Google-Weather-API Tutorial i'll post later this day

And it works ^^:

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URL myURL= new URL("http://www.google.com/images/weather/sunny.gif");
URLConnection conn = myURL.openConnection();
conn.connect();
InputStream is = conn.getInputStream();
Parsed in 0.033 seconds,  using GeSHi 1.0.8.4

Regards,
plusminus

Danuubz · by **Danuubz** » Fri Dec 21, 2007 6:17 pm

Aah yes it works. You sometimes just have to wait about 15-20 seconds ^^

Here's my code which downloads the first 20 tokens of this forum thread :lol:

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package com.google.android.webcheck;
 
import java.net.*;
 
import java.io.*;
 
import android.app.Activity;
 
import android.os.Bundle;
 
import android.widget.TextView;
 
public class WebCheck extends Activity 
 
{
 
        String myString = "Test: ";
 
    @Override
 
    public void onCreate(Bundle icicle) 
 
    {
 
        super.onCreate(icicle);
 
        TextView tv = new TextView(this);
 
        try
 
        {
 
                URL myURL = new URL("http://www.anddev.org/getting_data_from_the_web-t330.html");
 
                URLConnection ucon = myURL.openConnection();
 
                InputStream is = ucon.getInputStream();
 
                InputStream bis = new BufferedInputStream(is);
 
                Reader reader = new InputStreamReader(bis);
 
                int x;
 
                int count = 0;  
 
                byte by[] = new byte[20];
 
                while((x = reader.read()) != -1)
 
                {
 
                        if(count < 20)
 
                        {
 
                                by[count] = (byte) x;
 
                        }
 
                        count++;
 
                }
 
                for(int i=0; i<20; i++)
 
                {
 
                        myString = myString + (char)by[i];
 
                }
 
        }
 
        catch(MalformedURLException ex)
 
        {
 
                myString = "MalformedURLException occured.";
 
        }
 
        catch(IOException ex)
 
        {
 
                myString = "IOException occured.";
 
        }
 
        tv.setText(myString);
 
        setContentView(tv);
 
    }
 
}
 
Parsed in 0.041 seconds,  using GeSHi 1.0.8.4

Greets, Danuubz

plusminus · by **plusminus** » Fri Dec 21, 2007 9:11 pm

=D fine

Note: there are some shorter functions to achieve the same as you are (probably fast-coded

)

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is.read(<byte[] buf>);
String s = new String(<byte[] buf>);
Parsed in 0.035 seconds,  using GeSHi 1.0.8.4

Regards,
plusminus

Lex · by **Lex** » Fri Dec 21, 2007 10:42 pm

Allright thank you, now it works !
( Although the app doesn't work when the data is on http://localhost/ ... is there any way to make it work ? )

venkat · by **venkat** » Sat Dec 22, 2007 8:26 am

Hi Danuubz,
This is what i am looking for, thanks for you tutorial

. when i ran ur code i got IOException.

Actual Exception is "java.net.unknownHostException: Host is unresolved:www.anddev.org:80", i have attached my Screen shot.
i am behind the proxy and my port number is 3128.

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   URL myURL = new URL("http://www.anddev.org/getting_data_from_the_web-t330.html");
                           URLConnection ucon = myURL.openConnection();               
 
Parsed in 0.035 seconds,  using GeSHi 1.0.8.4

In above code i found that , using myURL.openConnection() we can set
proxy.

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myURL.openConnection(proxy)
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. I tried to set proxy settings, but i can't. can u tell me how set proxy from coding?

Thanks and regards

,
venkat.

Danuubz · by **Danuubz** » Sat Dec 22, 2007 12:49 pm

Hello venkat,

You can try to add

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System.setProperty("http.proxyHost"," **IP_OF_YOUR_PROXY** ");
 
System.setProperty("http.proxyPort","3128");
 
Parsed in 0.036 seconds,  using GeSHi 1.0.8.4

to the code (before the try-catch-block).

venkat · by **venkat** » Sat Dec 22, 2007 3:35 pm

Dear Danuubz,:)
Thanks for ur reply, It Works but, now i got new Error, I think i need to set authentication. Can u tell me how to set authentication. i have attached Screen shot of authentication.

Thanks and regards,
venkat.

Danuubz · by **Danuubz** » Sat Dec 22, 2007 3:56 pm

Hmm... maybe it works properly if you choose another URL... Try with http://www.google.de/index.html :wink:

plusminus · by **plusminus** » Sat Dec 22, 2007 4:40 pm

Hey guys,

transformed this issue into its :src: own tutorial (click).

Regards,
plusminus

venkat · by **venkat** » Sat Dec 22, 2007 4:44 pm

Hi Danuubz, i have changed URL but same error is repeating.

.
I have set user name and password also using following lines of code.

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                System.setProperty("http.proxyUser", "venkat"); 
 
                System.setProperty("http.proxyPassword", "password");
Parsed in 0.036 seconds,  using GeSHi 1.0.8.4

Thanks and regards,
Venkat.

pramod_taragi · by **pramod_taragi** » Mon Nov 17, 2008 6:36 am

Hi,
I am facing same problem of :Host is unresolved.
Please help me out.

getting data from the web

getting data from the web

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