JRasa

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A Java SDK for Rasa action server.

Maven

<dependency>
  <groupId>io.github</groupId>
  <artifactId>jrasa</artifactId>
  <version>0.1.0-SNAPSHOT</version>
</dependency>

Compatibility

Rasa: >= 3.x

Usage

You should read the Rasa SDK documentation first to figure out the fundamental concepts.

Running a Rasa SDK Action Server

You can run a Rasa SDK Action Server with the Java web framework you like. There is a SpringBoot demo for you.

Writing Custom Actions

Actions

To define a custom action, create a class which implements the interface Action.

import io.github.jrasa.Action;
import io.github.jrasa.CollectingDispatcher;
import io.github.jrasa.domain.Domain;
import io.github.jrasa.event.Event;
import io.github.jrasa.exception.RejectExecuteException;
import io.github.jrasa.tracker.Tracker;

import java.util.List;

public class CustomAction implements Action {
    @Override
    public String name() {
        return "action_name";
    }

    @Override
    public List<? extends Event> run(CollectingDispatcher collectingDispatcher, Tracker tracker, Domain domain) throws RejectExecuteException {
        return Action.empty();
    }
}

💡 If no events need to be returned, you can use Action.empty() to return an empty list.

Tracker

getSlot

Because Java is a static programming language, you have to assign the type when you get a slot value.

There is five methods to get a slot value:

• Object getSlot(String key)
• <T> T getSlot(String key, Class<T> type)
• String getStringSlot(String key)
• Boolean getBoolSlot(String key)
• Double getDoubleSlot(String key)

Object getSlot(String key) can get a slot value of any type.

With <T> T getSlot(String key, Class<T> type), you can assign the type of slot value.

String getStringSlot(String key) Boolean getBoolSlot(String key) Double getDoubleSlot(String key) can get the common type of slot value.

💡 Decimal numbers in JSON are deserialized to double in Java, so double is used instead of float.

Dispatcher

There is a Message class to represent responses, because methods don't support default value parameters in Java.

You can build a Message instance with Builder like this:

Message message = Message.builder()
                .text("Hello")
                .image("https://i.imgur.com/nGF1K8f.jpg")
                .response("utter_greet")
                .attachment("")
                .kwargs(new HashMap<String, Object>(){{
                    put("name", "uncle-lv");
                }})
                .build();

And then send it with utterMessage:

dispatcher.utterMessage(message);

Events

All events are subclasses of abstract class Event. Their properties are the same as in the documentation. Some of them with many properties should been build with Builder.

SlotSet

SlotSet SlotSet = new SlotSet("name", "Mary");

AllSlotsReset

AllSlotsReset allSlotsReset = new AllSlotsReset();

ReminderScheduled

ReminderScheduled reminderScheduled = ReminderScheduled.builder("EXTERNAL_dry_plant")
        .name("remind_water_plants")
        .entities(new ArrayList<Entity>(){{
            add(Entity.builder().entity("plant", "orchid").build());
        }})
      .triggerDateTime(LocalDateTime.parse("2018-09-03T11:41:10.128172", DateTimeFormatter.ISO_LOCAL_DATE_TIME))
        .build();

ReminderCancelled

ReminderCancelled reminderCancelled = ReminderCancelled.builder()
                .name("remind_water_plants")
                .build();

ConversationPaused

ConversationPaused conversationPaused = new ConversationPaused();

ConversationResumed

ConversationResumed conversationResumed = new ConversationResumed();

FollowupAction

FollowupAction followupAction = new FollowupAction("action_say_goodbye");

UserUtteranceReverted

UserUtteranceReverted userUtteranceReverted = new UserUtteranceReverted();

ActionReverted

ActionReverted actionReverted = new ActionReverted();

Restarted

Restarted restarted = new Restarted();

SessionStarted

SessionStarted sessionStarted = new SessionStarted();

UserUttered

UserUttered userUttered = UserUttered.builder()
                .text("Hello bot")
                .build();

BotUttered

BotUttered botUttered = BotUttered.builder()
                .text("Hello user")
                .build();

ActionExecuted

ActionExecuted actionExecuted = ActionExecuted.builder("action_greet_user")
                .build();

Special Action Types

Knowledge Base Actions

🛠️ Not implemented yet.

Slot Validation Actions

There is only one difference from the official SDK.

The methods/functions are named validate_<slot_name>/extract_<slot name>(snake case) in the official SDK. In JRasa, they should be named validate<SlotName>/extract<SlotName>(camel case), as naming convention in Java.

Contributions

Thank you for any feedback.

License

Apache-2.0

Thanks

• Rasa