9.7 KiB
- How to get picture?
- How to send photos?
- How do I send photos by file_id?
- How to use custom keyboards?
- How can I run my bot?
- How can I compile my project?
- Method
sendMessage()(or other) is deprecated, what should I do? - Is there any example for WebHook?
How to download photo?
To download a picture (or any other file), you will need the file_path of the file. Let start by finding the photo we want to download, the following method will extract the PhotoSize from a photo sent to the bot (in our case, we are taken the bigger size of those provided):
public PhotoSize getPhoto(Update update) {
// Check that the update contains a message and the message has a photo
if (update.hasMessage() && update.getMessage().hasPhoto()) {
// When receiving a photo, you usually get different sizes of it
List<PhotoSize> photos = update.getMessage().getPhoto();
// We fetch the bigger photo
return photos.stream()
.sorted(Comparator.comparing(PhotoSize::getFileSize).reversed())
.findFirst()
.orElse(null);
}
// Return null if not found
return null;
}
Once we have the photo we have to options: The file_path is already present or we need to get it, the following method will handle both of them and return the final file_path:
public String getFilePath(PhotoSize photo) {
Objects.requireNonNull(photo);
if (photo.hasFilePath()) { // If the file_path is already present, we are done!
return photo.getFilePath();
} else { // If not, let find it
// We create a GetFile method and set the file_id from the photo
GetFile getFileMethod = new GetFile();
getFileMethod.setFileId(photo.getFileId());
try {
// We execute the method using AbsSender::execute method.
File file = execute(getFileMethod);
// We now have the file_path
return file.getFilePath();
} catch (TelegramApiException e) {
e.printStackTrace();
}
}
return null; // Just in case
}
Now that we have the file_path we can download it:
public java.io.File downloadPhotoByFilePath(String filePath) {
try {
// Download the file calling AbsSender::downloadFile method
return downloadFile(filePath);
} catch (TelegramApiException e) {
e.printStackTrace();
}
return null;
}
The returned java.io.File object will be your photo
How to send photos?
There are several method to send a photo to an user using sendPhoto method: With a file_id, with an url or uploading the file. In this example, we assume that we already have the chat_id where we want to send the photo:
public void sendImageFromUrl(String url, String chatId) {
// Create send method
SendPhoto sendPhotoRequest = new SendPhoto();
// Set destination chat id
sendPhotoRequest.setChatId(chatId);
// Set the photo url as a simple photo
sendPhotoRequest.setPhoto(url);
try {
// Execute the method
sendPhoto(sendPhotoRequest);
} catch (TelegramApiException e) {
e.printStackTrace();
}
}
public void sendImageFromFileId(String fileId, String chatId) {
// Create send method
SendPhoto sendPhotoRequest = new SendPhoto();
// Set destination chat id
sendPhotoRequest.setChatId(chatId);
// Set the photo url as a simple photo
sendPhotoRequest.setPhoto(fileId);
try {
// Execute the method
sendPhoto(sendPhotoRequest);
} catch (TelegramApiException e) {
e.printStackTrace();
}
}
public void sendImageUploadingAFile(String filePath, String chatId) {
// Create send method
SendPhoto sendPhotoRequest = new SendPhoto();
// Set destination chat id
sendPhotoRequest.setChatId(chatId);
// Set the photo file as a new photo (You can also use InputStream with a method overload)
sendPhotoRequest.setNewPhoto(new File(filePath));
try {
// Execute the method
sendPhoto(sendPhotoRequest);
} catch (TelegramApiException e) {
e.printStackTrace();
}
}
How to send photo by its file_id?
In this example we will check if user sends to bot a photo, if it is, get Photo's file_id and send this photo by file_id to user.
// If it is a photo
if (update.hasMessage() && update.getMessage().hasPhoto()) {
// Array with photos
List<PhotoSize> photos = update.getMessage().getPhoto();
// Get largest photo's file_id
String f_id = photos.stream()
.sorted(Comparator.comparing(PhotoSize::getFileSize).reversed())
.findFirst()
.orElse(null).getFileId();
// Send photo by file_id we got before
SendPhoto msg = new SendPhoto()
.setChatId(update.getMessage().getChatId())
.setPhoto(f_id)
.setCaption("Photo");
try {
sendPhoto(msg); // Call method to send the photo
} catch (TelegramApiException e) {
e.printStackTrace();
}
}
How to use custom keyboards?
Custom keyboards can be appended to messages using the setReplyMarkup. In this example, we will build a simple ReplyKeyboardMarkup with two rows and three buttons per row, but you can also use other types like ReplyKeyboardHide, ForceReply or InlineKeyboardMarkup:
public void sendCustomKeyboard(String chatId) {
SendMessage message = new SendMessage();
message.setChatId(chatId);
message.setText("Custom message text");
// Create ReplyKeyboardMarkup object
ReplyKeyboardMarkup keyboardMarkup = new ReplyKeyboardMarkup();
// Create the keyboard (list of keyboard rows)
List<KeyboardRow> 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 {
// Send the message
execute(message);
} catch (TelegramApiException e) {
e.printStackTrace();
}
}
How can I run my bot?
You don't need to spend a lot of money into hosting your own telegram bot. Basically, there are two options around how to host:
- Hosting on your own hardware. It can be a Mini-PC like a Raspberry Pi. The costs for the hardware (~35€) and annual costs for power (~7-8€) are low. Keep in mind that your internet connection might be limited and a Mini-Pc is not ideal for a large users base.
- Run your bot in a Virtual Server/dedicated root server. There are many hosters out there that are providing cheap servers that fit your needs. The cheapest one should be openVZ-Containers or a KVM vServer. Example providers are Hetzner, DigitalOcean, (are providing systems that have a high availability but cost's a bit more) and OVH For a deeper explanation for deploying your bot on DigitalOcean please see the Lesson 5. Deploy your bot chapter in MonsterDeveloper's book
How can I compile my project?
This is just one way, how you can compile it (here with maven). The example below below is compiling the TelegramBotsExample repo.
Method sendMessage() (or other) is deprecated, what should I do?
Please use execute() instead.
Example:
SendMessage sn = new SendMessage();
//add chat id and text
execute(sn);
If you extend TelegramLongPollingCommandBot, then use AbsSender.execute() instead.
Is there any example for WebHook?
Please see the example Bot for https://telegram.me/SnowcrashBot in the TelegramBotsExample repo and also an example bot for Sping Boot from UnAfraid here