Android Blog: How to send and receive message using in android

I take a look at how can programmatically send and receive SMS messages in our Android applications. The good news for Android developers is that we don't need a real device to test out SMS messaging - the free Android emulator provides the capability to do so.

In the Main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Enter the phone number of recipient"
        />
    <EditText
        android:id="@+id/txtPhoneNo"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        />
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Message"
        />
    <EditText
        android:id="@+id/txtMessage"
        android:layout_width="fill_parent"
        android:layout_height="150px"
        android:gravity="top"
        />
    <Button
        android:id="@+id/btnSendSMS"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Send SMS"
        />
</LinearLayout>

Next, in the SMS activity, we wire up the Button view so that when the user clicks on it, we will check to see that the phone number of the recipient and the message is entered before we send the message using the sendSMS() function, which we will define shortly:

import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.telephony.gsm.SmsManager;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class SMS extends Activity {
    /** Called when the activity is first created. */
Button btnSendSMS;
     EditText txtPhoneNo;
     EditText txtMessage;
    @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();
            }

});
}
public void sendSMS(String phoneNo, String message) {

  String SENT = "SMS_SENT";
        String DELIVERED = "SMS_DELIVERED";

        PendingIntent sentPI = PendingIntent.getBroadcast(getApplicationContext(), 0,
            new Intent(SENT), 0);

        PendingIntent deliveredPI = PendingIntent.getBroadcast(getApplicationContext(), 0,
            new Intent(DELIVERED), 0);

        //---when the SMS has been sent---
        registerReceiver(new BroadcastReceiver(){
            @Override
            public void onReceive(Context arg0, Intent arg1) {
                switch (getResultCode())
                {
                    case Activity.RESULT_OK:
                        Toast.makeText(getBaseContext(), "SMS sent",
                                Toast.LENGTH_SHORT).show();
                        break;
                    case SmsManager.RESULT_ERROR_GENERIC_FAILURE:
                        Toast.makeText(getBaseContext(), "Generic failure",
                                Toast.LENGTH_SHORT).show();
                        break;
                    case SmsManager.RESULT_ERROR_NO_SERVICE:
                        Toast.makeText(getBaseContext(), "No service",
                                Toast.LENGTH_SHORT).show();
                        break;
                    case SmsManager.RESULT_ERROR_NULL_PDU:
                        Toast.makeText(getBaseContext(), "Null PDU",
                                Toast.LENGTH_SHORT).show();
                        break;
                    case SmsManager.RESULT_ERROR_RADIO_OFF:
                        Toast.makeText(getBaseContext(), "Radio off",
                                Toast.LENGTH_SHORT).show();
                        break;
                }
            }
        }, new IntentFilter(SENT));

        //---when the SMS has been delivered---
        registerReceiver(new BroadcastReceiver(){
            @Override
            public void onReceive(Context arg0, Intent arg1) {
                switch (getResultCode())
                {
                    case Activity.RESULT_OK:
                        Toast.makeText(getBaseContext(), "SMS delivered",
                                Toast.LENGTH_SHORT).show();
                        break;
                    case Activity.RESULT_CANCELED:
                        Toast.makeText(getBaseContext(), "SMS not delivered",
                                Toast.LENGTH_SHORT).show();
                        break;
                }
            }
        }, new IntentFilter(DELIVERED));

        SmsManager sms = SmsManager.getDefault();
        sms.sendTextMessage(phoneNo, null, message, sentPI, deliveredPI);

}
}

SMS messages are received, the onCreate() method will be invoked. The SMS message is contained and attached to the Intent object (intent - the second parameter in the onReceive() method) via a Bundle object. The messages are stored in an Object array in the 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:

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.gsm.SmsMessage;
import android.widget.Toast;

public 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();
         }
     }

}

Android uses a permission-based policy where all the permissions needed by an application need to be specified in the AndroidManifest.xml file. By doing so, when the application is installed it will be clear to the user what specific access permissions are required by the application.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.pack"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="8" />