How to schedule an SMS in Java

The most simple way to send SMS from Java is to use the built in HTTP/Rest SMS api of Ozeki SMS Gateway. When you use this API, you will send SMS messages by issuing a HTTP Post request to the SMS gateway. The HTTP Post request will contain a message formatted in json format. The SMS gateway will send this SMS to the recipient phone, and it will return a HTTP 200 OK response to your request.

how to send a scheduled sms from java
Figure 1 - How to send a scheduled SMS from Java

Java code to send sms to mobile

The Java sms code sample below demonstrates how you can send SMS using the http rest sms api of Ozeki SMS Gateawy using the Java Ozeki.Libs.Rest library. This library is provided to you free of charge, and you may use it and modify it in any of your projects.

Main.java 
import Ozeki.Libs.Rest.*;
import java.time.LocalDateTime;

public class Main {

    public static void main(String[] args) {

        var configuration = new Configuration();
        configuration.Username = "http_user";
        configuration.Password = "qwe123";
        configuration.ApiURL = "http://127.0.0.1:9509/api";

        var msg = new Message();
        msg.ToAddress = "+36201111111";
        msg.Text = "Hello world!";
        msg.TimeToSend = LocalDateTime.parse("2021-06-11T13:52:00");

        var api = new MessageApi(configuration);
        
        var result = api.Send(msg);
        
        System.out.println(result);
    }
}

How to use the Java sms example:

You can use the Message class to create the SMS and you can use the MessageApi class to send the SMS to the SMS gateway. The SMS gateway will forward your message to the mobile network either through a wireless connection or through the Internet.

Download SendScheduledSms.java

The source code explained in this article can be downloaded and used and modified free of charge.
Download: SendScheduledSms.java.zip (80.2Kb)

What is in the SendScheduledSms.java.zip file?

The SendScheduledSms.java.zip file contains the Ozeki library, which gives you all the tools neccessary to send and receive SMS messages. You will also find a Main.java file in the project, which contains the example code to show you how to send an SMS. This example code is listed below.

Figure 2 - SendScheduledSms.java directory

How to send scheduled SMS from Java (Quick steps)

To send scheduled sms from Java:

  1. Install Ozeki SMS Gateway
  2. Connect Ozeki SMS Gateway to the mobile network
  3. Send a test sms from Ozeki GUI
  4. Create a HTTP sms api user
  5. Apache NetBeans
  6. Create a project called SendScheduledSms
  7. Put the code into a newly created Main.java file or use the Main.java file in the .zip
  8. Create the SMS by creating a new Message object
  9. Create an api to send your message
  10. Use the Send method to send your message
  11. Specify the TimeToSend attribute of the newly created message
  12. Read the response message on the console
  13. Check the logs in the SMS gateway

Install Ozeki SMS Gateway and create an HTTP API user

To be able to send SMS from Java, first you need to install Ozeki SMS Gateway. The SMS gateway can be installed on the same computer, where you develop your Java code in Apache NetBeans. After installation, the next step is to connect Ozeki SMS Gateway to the mobile network. You can send a test sms from the Ozeki GUI to verify, that your mobile network connection works. The final step to prepare your environment is to create a HTTP sms api user. Create a user with a username of "http_user", and with a password of "qwe123" to make the example work without modification.

After the environment is setup, you can run your Java code.

HTTP API url to use send sms from Java

To send SMS from Java, your Java will will have to issue an HTTP request to the SMS gateway. The API url is shown below. Note that the IP address (127.0.0.1) should be replaced to the IP address of your SMS gateway. If Ozeki SMS Gateway is installed on the same computer where the Java sms application is running, this can be 127.0.0.1. If it is installed on a different computer it should be the IP address of that computer. 

http://127.0.0.1:9509/api?action=rest

HTTP authentication to use send sms from Java

To authenticate the Java sms client, you need to send the username and password in a base64 encoded string to the server in a HTTP request. The format used is: base64(username+":"+password). In Java you can use the following code to do this encoding: 

var usernamePassword = username + ":" + password;
var encodedUsernamePassword = usernamePassword.getBytes();
return "Basic " + Base64.getEncoder().encodeToString(encodedUsernamePassword);

For example if you encode the username 'http_user' and the password 'qwe123', you will get the following base64 encoded string: aHR0cF91c2VyOnF3ZTEyMw==. To send

HTTP request header to send scheduled SMS from Java

To send the scheduled SMS message, you need to include the following lines as headers in the HTTP request. Note that we include a content type and an Authorization header. 

Content-Type: application/json
Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==

HTTP request to send SMS from Java

To submit the SMS, your Java application will send an HTTP request similar to the one below. Note, that this requst contains a HTTP header part and a http body part. The HTTP body is a JSON encoded data string. It contains the recipient number and the messages text. 

POST /api?action=sendmsg HTTP/1.1
HTTP2-Settings: AAEAAEAAAAIAAAABAAMAAABkAAQBAAAAAAUAAEAA
Connection: Upgrade, HTTP2-Settings
Upgrade: h2c
Content-Length: 320
Content-Type: application/json
Accept: application/json
Authorization: Basic aHR0cF91c2VyOnF3ZTEyMw==
Host: 127.0.0.1:9509
User-Agent: Java-http-client/16.0.1

{
"messages":	[
	{
		"message_id": "5b9cea01-6bc0-42a7-9409-7b86eedf851b",
		"submit_report_requested": true,
		"view_report_requested": true,
		"valid_until": "2021-06-18 13:49:36",
		"time_to_send": "2021-06-11 13:52:00",
		"to_address": "+36201111111",
		"text": "Hello world!",
		"create_date": "2021-06-11 13:49:36",
		"delivery_report_requested": true
	}
]
}

HTTP response received by the Java sms example

Once the SMS gateway receives this request, it will generate a HTTP response. The HTTP response will contain a status code, to indicate whether the SMS submit request was successful or not. It will also return a JSON encoded structure to provide you useful details about the messages submission. 

HTTP/1.1 200 OK
User-Agent: OZEKI 10.3.120 (www.myozeki.com)
Content-Type: application/json; charset=utf8
Last-Modified: Fri, 11 Jun 2021 13:37:11 GMT
Server: 10/10.3.120
Transfer-Encoding: chunked

{
"http_code": 200,
"response_code": "SUCCESS",
"response_msg": "Messages queued for delivery.",
"data": {
  "total_count": 1,
  "success_count": 1,
  "failed_count": 0,
  "messages": [
    {
      "message_id": "5b9cea01-6bc0-42a7-9409-7b86eedf851b",
      "from_station": "%",
      "to_address": "+36201111111",
      "to_station": "%",
      "text": "Hello world!",
      "create_date": "2021-06-11 13:49:36",
      "valid_until": "2021-06-18 13:49:36",
      "time_to_send": "2021-06-11 13:52:00",
      "submit_report_requested": true,
      "delivery_report_requested": true,
      "view_report_requested": false,
      "tags": [
        {
          "name": "Type",
          "value": "SMS:TEXT"
        }
      ],
      "status": "SUCCESS"
    }
  ]
}
}

How to send SMS from Java using the Java sms api (Video tutorial)

This video shows you how to create a new project in Apache NetBeans, how to name it to SendScheduledSms. Once the solution is created, you might notice that a there is a folder called <default package> in your project inside the Source Packages folder. This is where you will create or paste the Main.java file. Then you have to paste the Ozeki folder into the Source packages folder and this is all the preparations you need to send an SMS using Java.

Video 1 - How to download Ozeki.Libs.Rest and set up your project

Java code to send sms to mobile

The Java sms code sample below demonstrates how you can send SMS using the http rest sms api of Ozeki SMS Gateawy using the Java Ozeki.Libs.Rest library. This library is provided to you free of charge, and you may use it and modify it in any of your projects.

Main.java 
import Ozeki.Libs.Rest.*;
import java.time.LocalDateTime;

public class Main {

    public static void main(String[] args) {

        var configuration = new Configuration();
        configuration.Username = "http_user";
        configuration.Password = "qwe123";
        configuration.ApiURL = "http://127.0.0.1:9509/api";

        var msg = new Message();
        msg.ToAddress = "+36201111111";
        msg.Text = "Hello world!";
        msg.TimeToSend = LocalDateTime.parse("2021-06-11T13:52:00");

        var api = new MessageApi(configuration);
        
        var result = api.Send(msg);
        
        System.out.println(result);
    }
}

How to use the Java sms example:

You can use the Message class to create the SMS and you can use the MessageApi class to send the SMS to the SMS gateway. The SMS gateway will forward your message to the mobile network either through a wireless connection or through the Internet.

Java sms example: Main.java

Figure 3 - SendScheduledSms project

How to check that the SMS has been accepted by the HTTP user

After the SMS has been submitted, it is a good idea to check your SMS gateway, to see what it has received. You can check the log by opening the HTTP user's details from the Ozeki SMS Gateway managment console. The following video shows you what to look for.

Video 2 - Sending a scheduled SMS with the Java code above

Conclusion

This article gave an insight into SMS scheduling in Java with Ozeki SMS Gateway. If you want to send out text messages in a specific time, SMS scheduling can be really helpful. Using this guide and the code above gives you all the knowledge and tools to make SMS scheduling possible. Ozeki SMS Gateway allows you to log messages into a database and offers numerous reporting capabilities in order to give you as much information as you need about the SMS communication.

Continue the reading on Ozeki's tutorial page, where more information can be found about topics like SMS deleting and receiving in Java.

The only thing to do now is to download Ozeki SMS Gateway and start working!

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