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Working with Webservices
Nilanjan Banerjee
Mobile Systems Programming
University of ArkansasFayetteville, AR
nilanjan.banerjee@gmail.com
Some of the simple web based services you would use!
Writing data to a database
Querying data from a database
Map queries (extracting maps, geocoding, reverse geocoding)
Other advanced webservices?
Optical Character Recognition System (OCR)
Relay services and Rendezvous Services
Speech to Text Service
General architecture for accessing databases
Mobile Phone
Intermediary Script (php, perl etc)
Backend database
Sending simple text data from a Mobile phone (Server side)– Adding userinfo --- username and password
$firstname = $_REQUEST["firstname"];$lastname = $_REQUEST["lastname"];$username = $_REQUEST["username"];$fpassword = $_REQUEST["fpassword"];
require_once('db.inc.php');
$insertquery="INSERT INTO table_name (first_name, last_name, user_name, fpassword) VALUES ('$firstname', '$lastname', '$username', '$fpassword’)";
$result = mysql_query($insertquery);mysql_close();
<?$user=”XXX";$password=”YYY";$database="weedidapp";$host="mpss.csce.uark.edu";mysql_connect($host,$user,$password);@mysql_select_db($database) or die( "Unable to select database");?>
- db.inc.php
Authenticating userinfo (server side)
<?php
foreach ($_GET as $key => $value) { eval("\$" . $key . " = \"" . $value . "\";");}
$username = $_REQUEST["username"];$fpassword = $_REQUEST["fpassword"];require_once('db.inc.php');$query="SELECT * from table where user_name='$username' AND fpassword='$fpassword'";$result = mysql_query($query);if($result && mysql_numrows($result)>0) echo "y”;else echo "n”;mysql_close();?>
– Check that the username password is present in the database– Note that this is all in plaintext. Ideally you would create a MD5
hash of the password and store the hash
Adding text to a mysql database
$latitude = $_REQUEST[”latitude"];$longitude = $_REQUEST[”longitude"];
require_once('db.inc.php');
$insertquery="INSERT INTO table_name (latitude, longitude) VALUES (’$latitude', '$longitude’)";
$result = mysql_query($insertquery);mysql_close();
– Send the data encoded in the url• For e.g., http://www.csce.uark.edu/~nilanb/insertdb.php?latitude=“-
31.5”;longitude=“-94.6”
– The url is parsed by the php script and a hashtable with <key, value> pairs are extraced
• _REQUEST[“latitude”] = -31.5• _REQUEST[“longitude”] = -94.6
Retrieving text from a mysql server and sending it backmysql_select_db("locationgame",$con);$list = mysql_list_tables("locationgame");$i = 0;$idarray = array();$latarray = array();$longarray = array();$count = 0;while($i < mysql_num_rows($list)){ $tb_names[$i] = mysql_tablename($list,$i); $sql = "SELECT * FROM $tb_names[$i] order by Date desc limit 1"; $result = mysql_query($sql, $con); $num = mysql_numrows($result); $j = 0; while($j < $num) { $fielddate=mysql_result($result,$j,"Date"); $fieldlatitude = mysql_result($result, $j, "Latitude"); $fieldlongitude = mysql_result($result, $j, "Longitude"); $phpdate = strtotime($fielddate); $dist = distance($fieldlatitude, $fieldlongitude, $latitude, $longitude); $idarray[] = $tb_names[$i]; $latarray[] = $fieldlatitude; $longarray[] = $fieldlongitude; $count ++; $j++; } $i++;}for ($i = 0; $i < $count; $i++){print "$idarray[$i] ”; print "$latarray[$i] ”; print "$longarray[$i] ”; print "\n”;}mysql_close($con);
Code on the phone
httpclient = new DefaultHttpClient();91 httppost = new HttpPost(php_script);92 // Add your data93 nameValuePairs = new ArrayList<NameValuePair>(2);94 nameValuePairs.add(new BasicNameValuePair("UserEmail", name.trim()));95 nameValuePairs.add(new BasicNameValuePair("Password", pass.trim()));96 httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));97 98 // Execute HTTP Post Request99 response = httpclient.execute(httppost);100 inputStream = response.getEntity().getContent();101 102 data = new byte[256];103 104 buffer = new StringBuffer();105 int len = 0;106 while (-1 != (len = inputStream.read(data)) )107 {108 buffer.append(new String(data, 0, len));109 }110 111 inputStream.close();
Uploading images to a mysql server
php script
Phone
database
folderName of image and attributes
enter where image is stored and itsCharacteristics (size etc)
Send actual images
storeImage in a folder
Schematic for upload of images
Image
Bitmap
ByteArrayOutputStream
byte
String (Base64 encoded) String
binary (Base64 decoded)
image
AndroidServer
Uploading images to the server
<?php$base=$_REQUEST['image'];echo $base;// base64 encoded utf-8 string$binary=base64_decode($base);// binary, utf-8 bytesheader('Content-Type: bitmap; charset=utf-8’);$file = fopen('test.jpg', 'wb');fwrite($file, $binary);fclose($file);echo '<img src=test.jpg>';?>
Sending images from the phone
29 byte [] byte_arr = stream.toByteArray();30 String image_str = Base64.encodeBytes(byte_arr);31 ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();32 33 nameValuePairs.add(new BasicNameValuePair("image",image_str));34 35 try{36 HttpClient httpclient = new DefaultHttpClient();37 HttpPost httppost = new HttpPost(php_script);38 httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));39 HttpResponse response = httpclient.execute(httppost);40 String the_string_response = convertResponseToString(response);42 }catch(Exception e){ }
Sending images from the phone (Response)
String res = ""; StringBuffer buffer = new StringBuffer(); inputStream = response.getEntity().getContent();
53 int contentLength = (int) response.getEntity().getContentLength(); 55 if (contentLength < 0){56 }57 else{58 byte[] data = new byte[512];59 int len = 0;60 try61 {62 while (-1 != (len = inputStream.read(data)) )63 {64 buffer.append(new String(data, 0, len)); 65 }66 }67 catch (IOException e)68 {}71 try72 {73 inputStream.close(); 74 }75 catch (IOException e)76 {}79 res = buffer.toString(); .83 }84 return res;85 }
SMS Sending• STEP 1
– In the AndroidManifest.xml file, add the two permissions - SEND_SMS and RECEIVE_SMS.
• STEP 2– In the main.xml, add Text
view to display "Enter the phone number of recipient“ and "Message"
– EditText with id txtPhoneNo and txtMessage
– Add the button ID "Send SMS“
SMS Sending
• Step 3 Import Classes and Interfacesimport android.app.Activity;import android.app.PendingIntent;import android.content.Intent;import android.os.Bundle;import android.telephony.SmsManager;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;
SMS Sending
Step 4 Write the SMS class public class SMS extends Activity { Button btnSendSMS; EditText txtPhoneNo; EditText txtMessage; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); btnSendSMS = (Button) findViewById(R.id.btnSendSMS); txtPhoneNo = (EditText) findViewById(R.id.txtPhoneNo); txtMessage = (EditText) findViewById(R.id.txtMessage); btnSendSMS.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { String phoneNo = txtPhoneNo.getText().toString(); String message = txtMessage.getText().toString();
if (phoneNo.length()>0 && message.length()>0) sendSMS(phoneNo, message); else Toast.makeText(getBaseContext(), "Please enter both phone number and message.", Toast.LENGTH_SHORT).show(); } }); } }
Input from the user (i.e., the phone no, text message and
sendSMS is implemented).
SMS Sending
Step 5◦ To send an SMS message, you use the SmsManager class.
And to instantiate this class call getDefault() static method.
◦ The sendTextMessage() method sends the SMS message with a PendingIntent.
◦ The PendingIntent object is used to identify a target to invoke at a later time.
private void sendSMS(String phoneNumber, String message) { PendingIntent pi = PendingIntent.getActivity(this, 0, new Intent(this, SMS.class), 0); SmsManager sms = SmsManager.getDefault(); sms.sendTextMessage(phoneNumber, null, message, pi, null);}
SMS Sending
Receiving SMS
• Step 1
Receiving SMS
• Step 2– In the AndroidManifest.xml file add the <receiver> element so
that incoming SMS messages can be intercepted by the SmsReceiver class.
<receiver android:name=".SmsReceiver"> <intent-filter> <action android:name= "android.provider.Telephony.SMS_RECEIVED" /> </intent-filter> </receiver>
Receiving SMS
• Step 3import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.telephony.SmsMessage;import android.widget.Toast;
Receiving SMS
Step 4public class SmsReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { //---get the SMS message passed in--- Bundle bundle = intent.getExtras(); SmsMessage[] msgs = null; String str = ""; if (bundle != null){ //---retrieve the SMS message received--- Object[] pdus = (Object[]) bundle.get("pdus"); msgs = new SmsMessage[pdus.length]; for (int i=0; i<msgs.length; i++) { msgs[i] = SmsMessage.createFromPdu((byte[])pdus[i]); str += "SMS from " + msgs[i].getOriginatingAddress(); str += " :"; str += msgs[i].getMessageBody().toString(); str += "\n"; } //---display the new SMS message--- Toast.makeText(context, str, Toast.LENGTH_SHORT).show(); } }}
In the SmsReceiver class, extend the
BroadcastReceiver class and override the
onReceive() method. The message is attached to
the Intent
The messages are stored in a object array PDU format. To extract each message, you use the static createFromPdu() method from the SmsMessage class. The SMS message is then displayed using the Toast class
Receiving SMS
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