This video demonstrates how to develop an SMS application in Android Studio using Java.

Software Required

Android Studio
Java SDK
Windows / Linux OS
Android Mobile Device

🔹 Theory (Short & Exam Friendly)

SMS stands for Short Message Service.

Android provides the SmsManager class to send SMS programmatically.

To send SMS, the application requires permission:

  <uses-permission android:name="android.permission.SEND_SMS"/>
  <uses-permission android:name="android.permission.READ_PHONE_STATE"/>

From Android 6.0 and above, runtime permission is also required.

🔹 Algorithm

1. Start the application.
2. Create EditText for mobile number and message.
3. Create Send button.
4. Ask for SMS permission.
5. Get mobile number and message text.
6. Use SmsManager to send SMS.
7. Display success or error message.
8. Stop.

💻 PROGRAM CODE

🔹 activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="20dp"

    >

    <EditText
        android:layout_marginTop="100dp"
        android:id="@+id/etPhone"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Enter Phone Number"
        android:inputType="phone" />

    <EditText
        android:id="@+id/etMessage"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:hint="Enter Message"
        android:inputType="textMultiLine"
        android:minLines="4" />

    <Button
        android:id="@+id/btnSend"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:text="Send SMS" />

</LinearLayout>

🔹 MainActivity.java

package com.example.demo;

import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.telephony.SmsManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

public class MainActivity extends AppCompatActivity {

    EditText phonenumber, MessageBox;
    Button btn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        phonenumber = findViewById(R.id.etPhone);
        MessageBox = findViewById(R.id.etMessage);
        btn = findViewById(R.id.btnSend);

        btn.setOnClickListener(v->{

            String phone = phonenumber.getText().toString();
            String Message = MessageBox.getText().toString();

            if (phone.isEmpty()){
                phonenumber.setError("Enter Phone Number");
            }
            if (Message.isEmpty()){
                MessageBox.setError("Enter Message");
            }
            if (ContextCompat.checkSelfPermission(this,Manifest.permission.SEND_SMS)==PackageManager.PERMISSION_GRANTED){
                
               try {
                   SmsManager smsManager = SmsManager.getDefault();
                   smsManager.sendTextMessage(phone,null,Message,null,null);
                   Toast.makeText(this, "message is sent successfully", Toast.LENGTH_SHORT).show();

               } catch (Exception e) {
                   Toast.makeText(this, "Failed to sent", Toast.LENGTH_SHORT).show();
               }
                

            }
            else {

                ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.SEND_SMS},1);

            }

        });

    }
}

🔹 AndroidManifest.xml

<uses-permission android:name="android.permission.SEND_SMS"/>
<uses-permission android:name="android.permission.READ_PHONE_STATE"/>

🔹 Output

• User enters mobile number
• User enters message
• Click on Send SMS button
• SMS is sent successfully
• Confirmation message displayed using Toast

🔹 Conclusion

Thus, an Android application was successfully developed to send SMS using SmsManager class.