Create a WhatsApp Bot in JAVA

mvn archetype:generate -DgroupId=com.example.whatsappbot -DartifactId=whatsapp-bot -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

// Import necessary libraries
import okhttp3.*; // OkHttp library for HTTP requests

public class SendMessageExample {
    public static void main(String[] args) throws Exception {
        // Step 1: Create an instance of OkHttpClient to send HTTP requests
        OkHttpClient client = new OkHttpClient();

        // Step 2: Define the media type for the request body (JSON in this case)
        MediaType mediaType = MediaType.parse("application/json");

        // Step 3: Create the JSON payload with the recipient's phone number and the message content
        /*
         * "to" - the recipient's WhatsApp number in international format (e.g., 919984351847)
         * "body" - the text message you want to send
         */
        RequestBody body = RequestBody.create(mediaType,
                "{\"to\":\"919984351847\",\"body\":\"Hello, world!\"}");

        // Step 4: Build the HTTP POST request
        Request request = new Request.Builder()
                .url("https://gate.whapi.cloud/messages/text") // API endpoint for sending text messages
                .post(body) // Attach the JSON payload in the request body
                .addHeader("accept", "application/json") // Accept JSON responses
                .addHeader("content-type", "application/json") // Specify JSON content type
                .addHeader("authorization", "Bearer YOUR_TOKEN") // Include your API token for authentication
                .build();

        // Step 5: Execute the request and receive the response
        Response response = client.newCall(request).execute();

        // Step 6: Print the response from the API to see the result
        /*
         * A successful response typically returns a JSON object with message details.
         * Use this information to confirm that the message was sent.
         */
        System.out.println(response.body().string());
    }
}

public void processMessages(List messages) {
    try {
        // Going through the list of all incoming messages
        for (MessagePayload message : messages) {

            // Ignore messages sent by the bot itself
            if (message.isFromMe())
                continue;

            // Get chatId - identifier of the chat from which the message came
            String chatId = message.getChatId();
            String response;

            // Handle text messages only
            if (message.getType().equals("text")) {
                // Retrieve the message body and convert to lower case for simplified processing
                String body = ((String) message.getText().get("body")).toLowerCase();

                switch (body) {
                    // Responding to “help” or “command” commands
                    case "help", "command" -> {
                        TextMessage txtMessage =
                            TextMessage.builder()
                                .to(chatId)
                                .body(responseMap.get(body)) // The message is taken from the prepared responseMap
                                .build();
                        response = postJson(txtMessage, "messages/text");
                    }

                    // Обработка мультимедиа-запросов: "video", "image", "document"
                    case "video", "image", "document" -> {
                        try (InputStream stream = getFile(body)) {
                            // Create the body of the request to send the file
                            RequestBody fileBody = RequestBody.create(
                                MediaType.parse(MediaTypeFactory.getMediaType(fileMap.get(body)).toString()),
                                stream.readAllBytes()
                            );

                            // Build a multipart request to send a media file
                            MultipartBody multipartBody = new MultipartBody.Builder()
                                .setType(MultipartBody.FORM)
                                .addFormDataPart("to", chatId) // Адресат
                                .addFormDataPart("media", fileMap.get(body), fileBody) // Сам файл
                                .addFormDataPart("caption", responseMap.get(body)) // Описание к медиа
                                .build();

                            response = postMultipart(multipartBody, "messages/" + body);
                        }
                    }

                    // Response to request to send contact card “vcard”
                    case "vcard" -> {
                        try (InputStream stream = getFile(body)) {
                            ContactMessage contactMessage =
                                ContactMessage.builder()
                                    .name("Whapi test")
                                    .to(chatId)
                                    .vcard(new String(stream.readAllBytes())) // vCard file in text form
                                    .build();
                            response = postJson(contactMessage, "messages/contact");
                        }
                    }

                    // Handling unknown commands: send default response
                    default -> {
                        TextMessage defaultMessage =
                            TextMessage.builder()
                                .to(chatId)
                                .body(responseMap.get("unknown"))
                                .build();
                        response = postJson(defaultMessage, "messages/text");
                    }
                }

                // Logging a successful response from the API
                log.info("Response received [{}]", response);
            } else {
                // Logging message types that are not yet processed
                log.warn("{} type not handled", message.getType());
            }
        }
    } catch (Exception e) {
        // Error handling during message processing
        log.error("Could not process the message " + e.getMessage());
    }
}

OkHttpClient client = new OkHttpClient();

MediaType mediaType = MediaType.parse("application/json");
RequestBody body = RequestBody.create(mediaType, "{\"participants\":[\"919984351847\",\"919984351848\",\"919984351849\"],\"subject\":\"Group Subject 99\"}");
Request request = new Request.Builder()
  .url("https://gate.whapi.cloud/groups")
  .post(body)
  .addHeader("accept", "application/json")
  .addHeader("content-type", "application/json")
  .addHeader("authorization", "Bearer YOUR_TOKEN")
  .build();

Response response = client.newCall(request).execute();