Lesson 2. Photo bot.
Our today’s mission — create a «photo» bot, that will send user a photo. It is just an example so there there will be no photos from online, no group chat support. Just local pics. But there is a good thing: we will learn how to create custom keyboards, how to send photos and create commands.
Let’s respect Telegram’s servers
Okey, for a start, let’s prepare our pictures. Lets download 5 completely unknown photos. Just look: we will send same files to users many many times, so lets coast our traffic and disk space on Telegram Servers. It is amazing that we can upload our files at their server once and then just send files (photos, audio files, documents, voice messages and etc.) by their unique file_id . Okey then. Now lets know photo’s file_id when we will send it to our bot. As always, create a new project in IntelliJ Idea and create two files within the src directory: Main.java and PhotoBot.java . Open up first file and type next:
import org.telegram.telegrambots.ApiContextInitializer; import org.telegram.telegrambots.TelegramBotsApi; import org.telegram.telegrambots.exceptions.TelegramApiException; public class Main < public static void main(String[] args) < ApiContextInitializer.init(); TelegramBotsApi botsApi = new TelegramBotsApi(); try < botsApi.registerBot(new PhotoBot()); > catch (TelegramApiException e) < e.printStackTrace(); >System.out.println("PhotoBot successfully started!"); > > This code will register our bot print «PhotoBot successfully started!» when it is successfully started. Then, save it and open up PhotoBot.java . Paste the following code from previous lesson:
Dont forget to change bot username and bot token if you created another bot.
import org.telegram.telegrambots.api.methods.send.SendMessage; import org.telegram.telegrambots.api.objects.Update; import org.telegram.telegrambots.bots.TelegramLongPollingBot; import org.telegram.telegrambots.exceptions.TelegramApiException; public class PhotoBot extends TelegramLongPollingBot < @Override public void onUpdateReceived(Update update) < // We check if the update has a message and the message has text if (update.hasMessage() && update.getMessage().hasText()) < // Set variables String message_text = update.getMessage().getText(); long chat_id = update.getMessage().getChatId(); SendMessage message = new SendMessage() // Create a message object object .setChatId(chat_id) .setText(message_text); try < sendMessage(message); // Sending our message object to user > catch (TelegramApiException e) < e.printStackTrace(); >> > @Override public String getBotUsername() < // Return bot username // If bot username is @MyAmazingBot, it must return 'MyAmazingBot' return "PhotoBot"; > @Override public String getBotToken() < // Return bot token from BotFather return "12345:qwertyuiopASDGFHKMK"; > > Now lets update our onUpdateReceived method. We want to send file_id of the picture we send to bot. Lets check if message contains photo object:
@Override public void onUpdateReceived(Update update) < // We check if the update has a message and the message has text if (update.hasMessage() && update.getMessage().hasText()) < // Set variables String message_text = update.getMessage().getText(); long chat_id = update.getMessage().getChatId(); SendMessage message = new SendMessage() // Create a message object object .setChatId(chat_id) .setText(message_text); try < sendMessage(message); // Sending our message object to user > catch (TelegramApiException e) < e.printStackTrace(); >> else if (update.hasMessage() && update.getMessage().hasPhoto()) < // Message contains photo > > We want our bot to send file_id of the photo. Well, lets do this:
else if (update.hasMessage() && update.getMessage().hasPhoto()) < // Message contains photo // Set variables long chat_id = update.getMessage().getChatId(); // Array with photo objects with different sizes // We will get the biggest photo from that array List photos = update.getMessage().getPhoto(); // Know file_id String f_id = photos.stream() .sorted(Comparator.comparing(PhotoSize::getFileSize).reversed()) .findFirst() .orElse(null).getFileId(); // Know photo width int f_width = photos.stream() .sorted(Comparator.comparing(PhotoSize::getFileSize).reversed()) .findFirst() .orElse(null).getWidth(); // Know photo height int f_height = photos.stream() .sorted(Comparator.comparing(PhotoSize::getFileSize).reversed()) .findFirst() .orElse(null).getHeight(); // Set photo caption String caption = "file_id: " + f_id + "\nwidth: " + Integer.toString(f_width) + "\nheight: " + Integer.toString(f_height); SendPhoto msg = new SendPhoto() .setChatId(chat_id) .setPhoto(f_id) .setCaption(caption); try < sendPhoto(msg); // Call method to send the photo with caption > catch (TelegramApiException e) < e.printStackTrace(); >> 
Amazing! Now we know photo’s file_id so we can send them by file_id. Lets make our bot answer with that photo when we send command /pic .
if (update.hasMessage() && update.getMessage().hasText()) < // Set variables String message_text = update.getMessage().getText(); long chat_id = update.getMessage().getChatId(); if (message_text.equals("/start")) < // User send /start SendMessage message = new SendMessage() // Create a message object object .setChatId(chat_id) .setText(message_text); try < sendMessage(message); // Sending our message object to user > catch (TelegramApiException e) < e.printStackTrace(); >> else if (message_text.equals("/pic")) < // User sent /pic SendPhoto msg = new SendPhoto() .setChatId(chat_id) .setPhoto("AgADAgAD6qcxGwnPsUgOp7-MvnQ8GecvSw0ABGvTl7ObQNPNX7UEAAEC") .setCaption("Photo"); try < sendPhoto(msg); // Call method to send the photo > catch (TelegramApiException e) < e.printStackTrace(); >> else < // Unknown command SendMessage message = new SendMessage() // Create a message object object .setChatId(chat_id) .setText("Unknown command"); try < sendMessage(message); // Sending our message object to user > catch (TelegramApiException e) < e.printStackTrace(); >> > Now bot sends photo like this:
And he can even reply to unknown command!
Now lets take a look at ReplyKeyboardMarkup. We will now create custom keyboard like this:
Well, you already now how to make our bot recognise command. Lets make another if for command /markup .
Remember! When you press the button, it will send to bot the text on this button. For example, if I put «Hello» text on the button, when I press it, it will send «Hello» text for me
else if (message_text.equals("/markup")) < SendMessage message = new SendMessage() // Create a message object object .setChatId(chat_id) .setText("Here is your keyboard"); // Create ReplyKeyboardMarkup object ReplyKeyboardMarkup keyboardMarkup = new ReplyKeyboardMarkup(); // Create the keyboard (list of keyboard rows) List keyboard = new ArrayList<>(); // Create a keyboard row KeyboardRow row = new KeyboardRow(); // Set each button, you can also use KeyboardButton objects if you need something else than text row.add("Row 1 Button 1"); row.add("Row 1 Button 2"); row.add("Row 1 Button 3"); // Add the first row to the keyboard keyboard.add(row); // Create another keyboard row row = new KeyboardRow(); // Set each button for the second line row.add("Row 2 Button 1"); row.add("Row 2 Button 2"); row.add("Row 2 Button 3"); // Add the second row to the keyboard keyboard.add(row); // Set the keyboard to the markup keyboardMarkup.setKeyboard(keyboard); // Add it to the message message.setReplyMarkup(keyboardMarkup); try < sendMessage(message); // Sending our message object to user > catch (TelegramApiException e) < e.printStackTrace(); >> Amazing! Now lets teach our bot to react on this buttons:
else if (message_text.equals("Row 1 Button 1")) < SendPhoto msg = new SendPhoto() .setChatId(chat_id) .setPhoto("AgADAgAD6qcxGwnPsUgOp7-MvnQ8GecvSw0ABGvTl7ObQNPNX7UEAAEC") .setCaption("Photo"); try < sendPhoto(msg); // Call method to send the photo > catch (TelegramApiException e) < e.printStackTrace(); >> Now, when user press button with «Row 1 Button 1» text on it, bot will send picture by file_id to user:
And lets add «Hide keyboard» function when user send /hide command to bot. This can be done with ReplyMarkupRemove .
else if (message_text.equals("/hide")) < SendMessage msg = new SendMessage() .setChatId(chat_id) .setText("Keyboard hidden"); ReplyKeyboardRemove keyboardMarkup = new ReplyKeyboardRemove(); msg.setReplyMarkup(keyboardMarkup); try < sendMessage(msg); // Call method to send the photo > catch (TelegramApiException e) < e.printStackTrace(); >> Here is code of our files. You can also find all sources at GitHub repository.
import org.telegram.telegrambots.ApiContextInitializer; import org.telegram.telegrambots.TelegramBotsApi; import org.telegram.telegrambots.exceptions.TelegramApiException; public class Main < public static void main(String[] args) < ApiContextInitializer.init(); TelegramBotsApi botsApi = new TelegramBotsApi(); try < botsApi.registerBot(new PhotoBot()); > catch (TelegramApiException e) < e.printStackTrace(); >System.out.println("PhotoBot successfully started!"); > > import org.telegram.telegrambots.api.methods.send.SendMessage; import org.telegram.telegrambots.api.methods.send.SendPhoto; import org.telegram.telegrambots.api.objects.PhotoSize; import org.telegram.telegrambots.api.objects.Update; import org.telegram.telegrambots.api.objects.replykeyboard.ReplyKeyboardMarkup; import org.telegram.telegrambots.api.objects.replykeyboard.ReplyKeyboardRemove; import org.telegram.telegrambots.api.objects.replykeyboard.buttons.KeyboardRow; import org.telegram.telegrambots.bots.TelegramLongPollingBot; import org.telegram.telegrambots.exceptions.TelegramApiException; import java.util.ArrayList; import java.util.Comparator; import java.util.List; public class PhotoBot extends TelegramLongPollingBot < @Override public void onUpdateReceived(Update update) < // We check if the update has a message and the message has text if (update.hasMessage() && update.getMessage().hasText()) < // Set variables String message_text = update.getMessage().getText(); long chat_id = update.getMessage().getChatId(); if (message_text.equals("/start")) < SendMessage message = new SendMessage() // Create a message object object .setChatId(chat_id) .setText(message_text); try < sendMessage(message); // Sending our message object to user > catch (TelegramApiException e) < e.printStackTrace(); >> else if (message_text.equals("/pic")) < SendPhoto msg = new SendPhoto() .setChatId(chat_id) .setPhoto("AgADAgAD6qcxGwnPsUgOp7-MvnQ8GecvSw0ABGvTl7ObQNPNX7UEAAEC") .setCaption("Photo"); try < sendPhoto(msg); // Call method to send the photo > catch (TelegramApiException e) < e.printStackTrace(); >> else if (message_text.equals("/markup")) < SendMessage message = new SendMessage() // Create a message object object .setChatId(chat_id) .setText("Here is your keyboard"); // Create ReplyKeyboardMarkup object ReplyKeyboardMarkup keyboardMarkup = new ReplyKeyboardMarkup(); // Create the keyboard (list of keyboard rows) List keyboard = new ArrayList<>(); // Create a keyboard row KeyboardRow row = new KeyboardRow(); // Set each button, you can also use KeyboardButton objects if you need something else than text row.add("Row 1 Button 1"); row.add("Row 1 Button 2"); row.add("Row 1 Button 3"); // Add the first row to the keyboard keyboard.add(row); // Create another keyboard row row = new KeyboardRow(); // Set each button for the second line row.add("Row 2 Button 1"); row.add("Row 2 Button 2"); row.add("Row 2 Button 3"); // Add the second row to the keyboard keyboard.add(row); // Set the keyboard to the markup keyboardMarkup.setKeyboard(keyboard); // Add it to the message message.setReplyMarkup(keyboardMarkup); try < sendMessage(message); // Sending our message object to user > catch (TelegramApiException e) < e.printStackTrace(); >> else if (message_text.equals("Row 1 Button 1")) < SendPhoto msg = new SendPhoto() .setChatId(chat_id) .setPhoto("AgADAgAD6qcxGwnPsUgOp7-MvnQ8GecvSw0ABGvTl7ObQNPNX7UEAAEC") .setCaption("Photo"); try < sendPhoto(msg); // Call method to send the photo > catch (TelegramApiException e) < e.printStackTrace(); >> else if (message_text.equals("/hide")) < SendMessage msg = new SendMessage() .setChatId(chat_id) .setText("Keyboard hidden"); ReplyKeyboardRemove keyboardMarkup = new ReplyKeyboardRemove(); msg.setReplyMarkup(keyboardMarkup); try < sendMessage(msg); // Call method to send the photo > catch (TelegramApiException e) < e.printStackTrace(); >> else < SendMessage message = new SendMessage() // Create a message object object .setChatId(chat_id) .setText("Unknown command"); try < sendMessage(message); // Sending our message object to user > catch (TelegramApiException e) < e.printStackTrace(); >> > else if (update.hasMessage() && update.getMessage().hasPhoto()) < // Message contains photo // Set variables long chat_id = update.getMessage().getChatId(); List photos = update.getMessage().getPhoto(); String f_id = photos.stream() .sorted(Comparator.comparing(PhotoSize::getFileSize).reversed()) .findFirst() .orElse(null).getFileId(); int f_width = photos.stream() .sorted(Comparator.comparing(PhotoSize::getFileSize).reversed()) .findFirst() .orElse(null).getWidth(); int f_height = photos.stream() .sorted(Comparator.comparing(PhotoSize::getFileSize).reversed()) .findFirst() .orElse(null).getHeight(); String caption = "file_id: " + f_id + "\nwidth: " + Integer.toString(f_width) + "\nheight: " + Integer.toString(f_height); SendPhoto msg = new SendPhoto() .setChatId(chat_id) .setPhoto(f_id) .setCaption(caption); try < sendPhoto(msg); // Call method to send the message > catch (TelegramApiException e) < e.printStackTrace(); >> > @Override public String getBotUsername() < // Return bot username // If bot username is @MyAmazingBot, it must return 'MyAmazingBot' return "PhotoBot"; > @Override public String getBotToken() < // Return bot token from BotFather return "12345:qwertyuiopASDGFHKMK"; > > Now you can create and remove custom ReplyMarkup keyboards, create custom commands and send photos by file_id ! You are doing very well! Hope to see you soon:)