An example of a chatbot written in java using the service API for Whatsapp greenapi.com. The chatbot clearly demonstrates the use of the API to send text messages, files, pictures, locations and contacts.
- Installing the environment for running the chatbot
- Launch chatbot
- Chatbot setup
- Usage
- Code structure
- Message management
To run the project you will need any IDE.
Open your code editor and create a new project from source control. To do this, click file - new - Project from Version Control System.
In the window that opens, enter the project address:
https://github.com/green-api/whatsapp-demo-chatbot-java.git
The environment for launching the chatbot is ready, now you need to configure and launch the chatbot on your Whatsapp account.
In order to set up a chatbot on your Whatsapp account, you need to go to your personal account and register. For new users, instructions are provided for setting up an account and obtaining the parameters necessary for the chatbot to work, namely:
idInstance
apiTokenInstance
Don't forget to enable all notifications in your instance settings.
After receiving these parameters, find the class BotStarter and enter idInstance and apiTokenInstance into the signature of the createBot() method.
Data initialization is necessary to link the bot with your Whatsapp account:
var bot = botFactory.createBot(
"{{INSTANCE}}",
"{{TOKEN}}");You can then run the program by clicking start in the IDE interface or entering the following query on the command line:
mvn clean install exec:java -Dexec.mainClass=com.greenapi.demoChatbot.BotStarter
This request will start the chatbot. The process begins with chatbot initialization, which includes changing the settings of the associated instance.
The library whatsapp-chatbot-java contains a mechanism for changing instance settings using the SetSettings method, which is launched when the chatbot is turned on.
All settings for receiving notifications are disabled by default; the chatbot will enable the following settings:
"incomingWebhook": "yes",
"outgoingMessageWebhook": "yes",
"outgoingAPIMessageWebhook": "yes",
which are responsible for receiving notifications about incoming and outgoing messages.
The process of changing settings takes several minutes, during which time the instance will be unavailable. Messages sent to the chatbot during this time will not be processed.
After the settings are applied, notifications about previously received incoming messages will be deleted. This process is also written in the library whatsapp-chatbot-java and starts automatically after changing the settings.
This is necessary so that the chatbot does not start processing messages from old chats.
After changing the settings and deleting incoming notifications, the chatbot will begin to respond to messages as standard. In total, this process takes no more than 5 minutes.
To stop the chatbot, use the keyboard shortcut Ctrl + C in the command line.
By default, the chatbot uses links to download files from the network, but users can add their own links to files, one for a file of any extension pdf / docx /... and one for a picture.
Links must lead to files from cloud storage or public access. In the class Endpoints the following code:
case "2" -> {
answerWithUrlFile(incomingMessage,
YmlReader.getString(new String[]{"send_file_message", lang.getValue()}) +
YmlReader.getString(new String[]{"links", lang.getValue(), "send_file_documentation"}),
"https://images.rawpixel.com/image_png_1100/cHJpdmF0ZS9sci9pbWFnZXMvd2Vic2l0ZS8yMDIzLTExL3Jhd3BpeGVsb2ZmaWNlMTlfcGhvdG9fb2ZfY29yZ2lzX2luX2NocmlzdG1hc19zd2Vhd GVyX2luX2FfcGFydF80YWM1ODk3Zi1mZDMwLTRhYTItYWM5NS05YjY3Yjg1MTFjZmUucG5n.png",
"corgi.png");
return currentState;
}Add a link to a file of any extension as the third parameter of the answerWithUrlFile method and specify the file name in the fourth parameter. The file name must contain an extension, for example "somefile.pdf".
This line after modification will be in the following format:
case "2" -> {
answerWithUrlFile(incomingMessage,
YmlReader.getString(new String[]{"send_file_message", lang.getValue()}) +
YmlReader.getString(new String[]{"links", lang.getValue(), "send_file_documentation"}),
"https://...somefile.pdf",
"somefile.pdf");All changes must be saved, after which you can launch the chatbot. To launch the chatbot, return to step 2.
If the previous steps have been completed, then the chatbot should be working on your Whatsapp account. It is important to remember that the user must be authorized in personal account.
Now you can send messages to the chatbot!
The chatbot will respond to any message sent to your account. Since the chatbot supports 2 languages - Russian and English - before greeting the interlocutor, the chatbot will ask you to select a language of communication:
1 - English
2 - Russian
Answer 1 or 2 to select the language for further communication. After you send 1, the chatbot will send a welcome message in English:
Welcome to GREEN-API chatbot, user! GREEN-API provides the following types of data sending. Select a number from the list to check how the sending method works
1. Text message 📩
2. File 📋
3. Picture 🖼
4. Contact 📱
5. Geolocation 🌎
6. ...
To return to the beginning write stop
By selecting a number from the list and sending it, the chatbot will answer which API sent this type of message and share a link to information about the API.
For example, by sending 1, the user will receive in response:
This message was sent by sendMessage method
To find out how the method works, follow the link
https://green-api.com/docs/api/sending/SendMessage/
If you send something other than numbers 1-11, the chatbot will succinctly answer:
Sorry, I didn't quite understand you, write a menu to see the possible options
The user can also call up the menu by sending a message containing “menu”. And by sending “stop”, the user will end the conversation with the chatbot and receive the message:
Thank you for using the GREEN-API chatbot, user!
The main file of the chatbot is BotStarter, it contains the main method and program execution begins with it. In this class, the bot object is initialized using the BotFactory class, the first scene is set, and the bot is launched.
public static void main(String[] args) {
var context = SpringApplication.run(BotStarter.class, args); //Initiate the Spring application context
var botFactory = context.getBean(BotFactory.class); //Import BotFactory bean from context
var bot = botFactory.createBot( //Initialize the bot with INSTANCE and TOKEN parameters
"{{INSTANCE}}",
"{{TOKEN}}");
bot.setStartScene(new Start()); //Setting the bot's starting scene
bot.startReceivingNotifications(); //Start the bot
}The BotFactory class is a Bean that is configured in BotConfig. His task is to create a bot object.
In the BotConfig configuration you can fine-tune the RestTemplate class for sending requests or substitute your own StateManager implementation if you have one.
In this example, BotConfig uses standard, recommended default values.
@Configuration
public class BotConfig {
@Bean
public RestTemplate restTemplate() { //Standard Spring class for sending http requests.
return new RestTemplateBuilder().build();
}
@Bean
public StateManager stateManager() { //StateManager - interface for working with state.
return new StateManagerHashMapImpl(); //StateManagerHashMapImpl is its standard implementation. You can write your own and substitute it if you do not want to store the data in a hashmap.
}
@Bean
public BotFactory botFactory(RestTemplate restTemplate, StateManager stateManager) { //BotFactory bean to initialize the bot object
return new BotFactory(restTemplate, stateManager);
}
}This bot uses a scene pattern to organize its code. This means that the chatbot logic is divided into fragments (scenes), the scene corresponds to a certain state of the dialogue and is responsible for processing the response.
Only one scene can be active at a time for each dialogue.
For example, the first scene Start is responsible for the welcome message. Regardless of the text of the message, the bot asks what language is convenient for the user and includes the following scene, which is responsible for processing the response.
There are 3 scenes in the bot:
- Scene
Start- responds to any incoming message, sends a list of available languages. Launches theMainMenuscene. - Scene
MainMenu- processes the user's selection and sends the main menu text in the selected language. Launches theEndpointsscene. - Scene
Endpoints- executes the user-selected method and sends a description of the method in the selected language.
The SessionManager class contains the isSessionExpired method which returns true if the user does not write to the bot for more than 2 minutes. It is used to set the starting scene again if the bot has not been contacted for a long time.
The YmlReader class contains the getString() method which returns strings from the strings.xml file by key. This file is used to store the texts of the bot's responses.
As the chatbot indicates in its responses, all messages are sent via the API. Documentation on message sending methods can be found at greenapi.com/en/docs/api/sending.
As for receiving messages, messages are read through the HTTP API. Documentation on methods for receiving messages can be found at greenapi.com/en/docs/api/receiving/technology-http-api.
The chatbot uses the library whatsapp-chatbot-java, where methods for sending and receiving messages are already integrated, so messages are read automatically and sending regular text messages is simplified .
For example, the chatbot automatically sends a message to the contact from whom it received the message:
answerWithText(incomingMessage, YmlReader.getString(new String[]{"select_language"}));However, other send methods can be called directly from the whatsapp-api-client-java library. Like, for example, when receiving an avatar:
greenApi.service.getAvatar(incomingMessage.getSenderData().getChatId());Licensed under Creative Commons Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0).