Get data from an internet link in Android
I am making an application which takes a URL with. *.asp extension and we pass it the required parameters and get some string result using POST method.
Any suggestions on how to achie开发者_如何学Pythonve this?
UPDATED:
Actually I have a .net link which takes some POST Parameters and gives me a Result. How can I do that in Android?
HTTPResponse should do the trick:
DefaultHttpClient  httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://www.yoururl.com");
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1); <!-- number should be the amount of parameters
nameValuePairs.add(new BasicNameValuePair("nameOfParameter", "parameter"));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity ht = response.getEntity();
BufferedHttpEntity buf = new BufferedHttpEntity(ht);
InputStream is = buf.getContent();
Now you got a stream to work with, to write the data to a string:
BufferedReader r = new BufferedReader(new InputStreamReader(is));
total = new StringBuilder();
String line;
while ((line = r.readLine()) != null) {
     total.append(line);
}
Good luck!
try using an AsynTask ( http://developer.android.com/reference/android/os/AsyncTask.html ) and never try to make any time consuming tasks in the onCreate call or any other GUI thread method.
Here is the code of an Android activity that does a POST request (including parameters) and displays the received response in an Android notification:
package org.anddev.android.webstuff;
import java.io.ByteArrayInputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.apache.http.util.ByteArrayBuffer;
import android.app.Activity;
import android.app.NotificationManager;
import android.net.http.EventHandler;
import android.net.http.Headers;
import android.net.http.RequestQueue;
import android.net.http.SslCertificate;
import android.os.Bundle;
import android.util.Log;
public class HTTPPostExample extends Activity {
        // ===========================================================
        // Fields
        // ===========================================================
        private final String DEBUG_TAG = "httpPostExample";
        // ===========================================================
        // 'Constructors'
        // ===========================================================
        @Override
        public void onCreate(Bundle icicle) {
                super.onCreate(icicle);
                /* Create a new HTTP-RequestQueue. */
                android.net.http.RequestQueue rQueue = new RequestQueue(this);
                /* Prepare the Post-Text we are going to send. */
                String POSTText = null;
                try {
                        POSTText = "mydata=" + URLEncoder.encode("HELLO, ANDROID HTTPPostExample - by anddev.org", "UTF-8");
                } catch (UnsupportedEncodingException e) {
                        return;
                }
                /* And put the encoded bytes into an BAIS,
                 * where a function later can read bytes from. */
                byte[] POSTbytes = POSTText.getBytes();
                ByteArrayInputStream baos = new ByteArrayInputStream(POSTbytes);
                /* Create a header-hashmap */
                Map<String, String> headers = new HashMap<String, String>();
                /* and put the Default-Encoding for html-forms to it. */
                headers.put("Content-Type", "application/x-www-form-urlencoded");
                /* Create a new EventHandler defined above, to handle what gets returned. */
                MyEventHandler myEvH = new MyEventHandler(this);
                /* Now we call a php-file I prepared. It is exactly this:
                 * <?php
                 *              echo "POSTed data: '".$_POST['data']."'";
                 * ?>*/
                rQueue.queueRequest("http://www.anddev.org/postresponse.php", "POST",
                                headers, myEvH, baos, POSTbytes.length,false);
                /* Wait until the request is complete.*/
                rQueue.waitUntilComplete();
        }
        // ===========================================================
        // Worker Class
        // ===========================================================
        private class MyEventHandler implements EventHandler {
                private static final int RANDOM_ID = 0x1337;
                /** Will hold the data returned by the URLCall. */
                ByteArrayBuffer baf = new ByteArrayBuffer(20);
                /** Needed, as we want to show the results as Notifications. */
                private Activity myActivity;
                MyEventHandler(Activity activity) {
                        this.myActivity = activity;  }
                public void data(byte[] bytes, int len) {
                        baf.append(bytes, 0, len);  }
                public void endData() {
                        String text = new String(baf.toByteArray());
                        myShowNotificationAndLog("Data loaded: n" + text);  }
                public void status(int arg0, int arg1, int arg2, String s) {
                        myShowNotificationAndLog("status [" + s + "]");  }
                public void error(int i, String s) {
                        this.myShowNotificationAndLog("error [" + s + "]");  }
                public void handleSslErrorRequest(int arg0, String arg1, SslCertificate arg2) { }
                public void headers(Iterator arg0) { }
                public void headers(Headers arg0) { }
                private void myShowNotificationAndLog(String msg) {
                        /* Print msg to LogCat and show Notification. */
                        Log.d(DEBUG_TAG, msg);
                        NotificationManager nm = (NotificationManager) this.myActivity
                                        .getSystemService(Activity.NOTIFICATION_SERVICE);
                        nm.notifyWithText(RANDOM_ID, msg, NotificationManager.LENGTH_LONG, null);
                }
        }
}
Code by plusminus
 
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