You may try any one of them:

Solution 1:

Step 1: Connect the Phone/Dongle to the COM Port via USB.

Step 2: Call the code for fetching sms via smslib.jar

Sample Code to fetch sms:

public void sendSMS() throws Exception{
    OutboundNotification outboundNotification = new OutboundNotification();
    SerialModemGateway gateway = new SerialModemGateway("modem.com5", "COM5", 9600, "ZTE", "COM5");
    gateway.setInbound(true);
    gateway.setOutbound(true);
    gateway.setSmscNumber("+91XXXXXXXXXX"); // 10-digit Mobile Number
    Service.getInstance().setOutboundMessageNotification(outboundNotification);
    Service.getInstance().addGateway(gateway);
    Service.getInstance().startService();
    OutboundMessage msg = new OutboundMessage(ExcelConnect.strSMSTo, ExcelConnect.strSMSText);
    Service.getInstance().sendMessage(msg);
    System.out.println(msg);
    System.out.println(ExcelConnect.strSMSTo + "-" + ExcelConnect.strSMSText);
    Service.getInstance().stopService();
    Service.getInstance().removeGateway(gateway);
}

Step 3: Parse sms to get the OTP from the fetched list by latest received sms

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Solution 2:

Step 1: Connect the android phone / iphone.

Step 2: Automate the SMS App in either of the phone, if its android - automate SMS app via appium(or any other automating app) or if its iphone - automate its SMS app feature.

to get the SMS and parse it to get the OTP

.

Solution 3:

Step 1: Register for the HTTP SMS Gateway(Most of them provide paid API Call with very few free API Calls for testing).

Step 2: Call the method to fetch SMS.

Step 3: Parse the message(after sorting it by latest received sms) to get the OTP

.

These three ways you can get the OTP and then you can send it to you Web Application.

.

Solution 4:

Get the OTP from DB, if its in-house application or if it can be accessed.

.

'Solution 3 and Solution 4' being most efficient and it doesn't have any dependency on sms receiving platforms.

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Solutions consolidated below: