Skip to main content

Creating a Chatbot with RiveScript in Java

Motivation

"Artificial Intelligence (AI) is considered a major innovation that could disrupt many things. Some people even compare it to the Internet. A large investor firm predicted that some AI startups could become the next Apple, Google or Amazon within five years" 
- Prof. John Vu, Carnegie Mellon University.

Using chatbots to support our daily tasks is super useful and interesting. In fact, "Jenkins CI, Jira Cloud, and Bitbucket" have been becoming must-have apps in Slack of my team these days.

There are some existing approaches for chatbots including pattern matching, algorithms, and neutral networks. RiveScript is a scripting language using "pattern matching" as a simple and powerful approach for building up a Chabot.

Architecture

Actually, it was flexible to choose a programming language for the used Rivescript interpreter like Java, Go, Javascript, Python, and Perl. I went with Java.


Used Technologies and Tools

  • Oracle JDK 1.8.0_151
  • Apache Maven 3.5.2
  • Apache Tomcat 7.0.85
  • RiveScript-Java
  • Jersey sever/client
  • MyFaces

Module ChatBot Backend

I had a backend for chatbot's brain which provided APIs responding to received messages from users via a GUI.

1. Generate a web app project via Maven

mvn archetype:generate \
-DgroupId=vn.nvanhuong \
-DartifactId=chatbot_rivescript_backend \
-DarchetypeArtifactId=maven-archetype-webapp \
-DinteractiveMode=false;

Tips: When importing the project into Eclipse, I encountered an error "The superclass "javax.servlet.http.HttpServlet" was not found on the Java Build Path". I solved it by "Right click on the project/Properties/Project Facets/Runtimes/Check Apache Tomcat v.7.0"

2. Add dependencies needed in `pom.xml`

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <groupId>vn.nvanhuong</groupId>
 <artifactId>chatbot_rivescript_backend</artifactId>
 <packaging>war</packaging>
 <version>1.0-SNAPSHOT</version>
 <name>chatbot_rivescript_backend Maven Webapp</name>
 <url>http://maven.apache.org</url>

 <dependencies>
  <!-- ChatBot Brain -->
  <dependency>
   <groupId>com.rivescript</groupId>
   <artifactId>rivescript-core</artifactId>
   <version>0.10.0</version>
  </dependency>

  <!-- RESTful APIs -->
  <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-server</artifactId>
   <version>1.8</version>
  </dependency>

  <!-- JSON -->
  <dependency>
   <groupId>org.json</groupId>
   <artifactId>json</artifactId>
   <version>20160810</version>
  </dependency>

  <!-- Unit tests -->
  <dependency>
   <groupId>junit</groupId>
   <artifactId>junit</artifactId>
   <version>4.12</version>
   <scope>test</scope>
  </dependency>
 </dependencies>

 <build>
  <finalName>chatbot_rivescript_backend</finalName>
 </build>
</project>

3. Create chatbot's brain with RiveScript

I created a file "chatbot_brain.rive" under the folder "src/main/resources/rivescript". I copied the content of template file "rs_standard.rive" at https://www.rivescript.com/try
+ hello bot
- Hello human!

4. Create RESTful APIs

package vn.nvanhuong.chatbot.rivescript.backend;

import javax.ws.rs.POST;
import javax.ws.rs.Path;

import com.rivescript.Config;
import com.rivescript.RiveScript;
import com.sun.jersey.spi.resource.Singleton;

@Path("/bot")
@Singleton
public class ChatBot {
 private RiveScript bot;
 
 public ChatBot() {
  String rivescriptFilePath = ChatBot.class.getClassLoader().getResource("rivescript").getFile();
  bot = new RiveScript(Config.utf8());
  
  bot.loadDirectory(rivescriptFilePath);
        bot.sortReplies();
 }
 
 @POST
 public String getMsg(String msg) {
  return bot.reply("user", msg);
 }

}

5. Configure RESTful at `web.xml`

<web-app id="WebApp_ID" version="2.4"
 xmlns="http://java.sun.com/xml/ns/j2ee"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
 http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
 <display-name>Restful Web Application</display-name>

 <servlet>
  <servlet-name>jersey-serlvet</servlet-name>
  <servlet-class>
                     com.sun.jersey.spi.container.servlet.ServletContainer
                </servlet-class>
  <init-param>
       <param-name>com.sun.jersey.config.property.packages</param-name>
       <param-value>vn.nvanhuong.chatbot.rivescript.backend</param-value>
  </init-param>
  <load-on-startup>1</load-on-startup>
 </servlet>

 <servlet-mapping>
  <servlet-name>jersey-serlvet</servlet-name>
  <url-pattern>/rest/*</url-pattern>
 </servlet-mapping>

</web-app>

6. Write a test case

package vn.nvanhuong.chatbot.rivescript.backend.test;

import static org.junit.Assert.assertEquals;

import org.junit.Test;

import vn.nvanhuong.chatbot.rivescript.backend.ChatBot;

public class ChatBotTest {
 
 @Test
 public void should_say_hello() {
  ChatBot bot = new ChatBot();
  
  assertEquals("Hello Human!", bot.getMsg("Hello Bot"));
 }
}

7. Test the API with Postman

URL: http://localhost:8080/chatbot_rivescript_backend/rest/bot

Module ChatBot GUI

1. Generate a web app project via Maven

mvn archetype:generate \
-DgroupId=vn.nvanhuong \
-DartifactId=chatbot_rivescript_gui \
-DarchetypeArtifactId=maven-archetype-webapp \
-DinteractiveMode=false

2. Add dependencies needed in pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <groupId>vn.nvanhuong</groupId>
 <artifactId>chatbot_rivescript_gui</artifactId>
 <packaging>war</packaging>
 <version>1.0-SNAPSHOT</version>
 <name>chatbot_rivescript_gui Maven Webapp</name>
 <url>http://maven.apache.org</url>

 <dependencies>
  <!-- JAX-RS Client -->
  <dependency>
   <groupId>org.glassfish.jersey.core</groupId>
   <artifactId>jersey-client</artifactId>
   <version>2.25.1</version>
  </dependency>

  <!-- JSF Pages -->
  <dependency>
   <groupId>org.apache.myfaces.core</groupId>
   <artifactId>myfaces-api</artifactId>
   <version>2.2.0</version>
  </dependency>
  <dependency>
   <groupId>org.apache.myfaces.core</groupId>
   <artifactId>myfaces-impl</artifactId>
   <version>2.2.0</version>
  </dependency>

  <!-- Unit test -->
  <dependency>
   <groupId>junit</groupId>
   <artifactId>junit</artifactId>
   <version>4.12</version>
   <scope>test</scope>
  </dependency>
 </dependencies>

 <build>
  <finalName>chatbot_rivescript_gui</finalName>
 </build>
</project>

3. Configure JSF at web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 xmlns="http://java.sun.com/xml/ns/javaee"
 xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
 version="2.5">
  
 <!-- JSF mapping -->
 <servlet>
  <servlet-name>Faces Servlet</servlet-name>
  <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
  <load-on-startup>1</load-on-startup>
 </servlet>
 <servlet-mapping>
  <servlet-name>Faces Servlet</servlet-name>
  <url-pattern>*.xhtml</url-pattern>
 </servlet-mapping>
   
  <!-- welcome page -->
  <welcome-file-list>
    <welcome-file>index.xhtml</welcome-file>
  </welcome-file-list>
</web-app>

4. Create a GUI

Rename index.jsp to index.xthml

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
 xmlns:f="http://java.sun.com/jsf/core"
 xmlns:h="http://java.sun.com/jsf/html"
 xmlns:p="http://xmlns.jcp.org/jsf/passthrough">
 <h:head>
  <title>RiveScript</title>
  <style>
   
   .container {
    display: block;
     margin: 50px auto;
     width: 90%;
   }
   
   .chatbox {
    height: 600px;
     border: solid 1px #039;
     background-image: url(bot_logo.png);
     background-repeat: no-repeat;
     background-position: center;
     background-size: contain;
     display: flex;
     justify-content: center;
     align-items: center;
   }
   
   .chatbox .bot-dialog {
    width: 90%;
     border: dashed 1px purple;
     text-align: center;
     background-color: orange;
   }
   
   .chatbox .bot-dialog > span{
    font-size: larger;
   }
   
   .message {
    display: flex;
    justify-content: space-between;
    
   }
   .message > input.message-input {
    width: 90%;
    margin-top: 10px;
    line-height: 2.3;
   }
   
   .message > input.submit {
    width: 9%;
     background-color: #039;
     color: white;
     font-size: 15px;
     margin-top: 10px;
   }
   
   .message-display > span {
     font-style: italic;
 }
 .message-display > label {
     font-weight: bold;
 }
 .message-display {
     margin-top: 5px;
 }
   
  </style>
 </h:head>
 <h:body>
 <h:form>
    <h:panelGroup layout="block" styleClass="container">
      <h:panelGroup layout="block" styleClass="chatbox">
       <h:panelGroup layout="block" styleClass="bot-dialog">
        <h:outputText id="botMessage" value="#{controller.botMessage}" escape="false"/>
       </h:panelGroup>
      </h:panelGroup>
      
      <h:panelGroup layout="block" styleClass="message">
       <h:inputText id="input" value="#{controller.humanMessage}" styleClass="message-input" 
        p:placeholder="Send a message to the bot"
        p:autofocus="true"
        onblur="this.focus()"/>
       <h:commandButton id="button" value="Send" actionListener="#{controller.onSend}" styleClass="submit"/>
      </h:panelGroup>
      
      <h:panelGroup layout="block" styleClass="message-display" rendered="#{not empty controller.humanMessageDisplay}">
       <h:outputLabel for="messageDisplay" value="You just said: "/>
       <h:outputText id="messageDisplay" value="#{controller.humanMessageDisplay}"/>
      </h:panelGroup>
    </h:panelGroup>
 </h:form>
 </h:body>
</html>

5. Create a Controller to call the RESTful APIs

package vn.vanhuong.chatbot.rivescript.gui;

import javax.faces.bean.ManagedBean;
import javax.faces.event.ActionEvent;
import javax.ws.rs.client.ClientBuilder;
import javax.ws.rs.client.Entity;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;

@ManagedBean(name = "controller")
public class Controller {
 
 private String humanMessage;
 private String botMessage;
 private String humanMessageDisplay;

 public void onSend(ActionEvent event) {
  Response response = ClientBuilder.newClient().target("http://localhost:8080/chatbot_rivescript_backend/rest/bot")
    .request(MediaType.APPLICATION_FORM_URLENCODED)
    .post(Entity.entity(humanMessage, MediaType.APPLICATION_FORM_URLENCODED));
  this.botMessage = response.readEntity(String.class);
  this.humanMessageDisplay = humanMessage;
  this.humanMessage = null;
 }

 public String getHumanMessage() {
  return humanMessage;
 }

 public void setHumanMessage(String humanMessage) {
  this.humanMessage = humanMessage;
 }

 public String getBotMessage() {
  return botMessage;
 }

 public void setBotMessage(String botMessage) {
  this.botMessage = botMessage;
 }

 public String getHumanMessageDisplay() {
  return humanMessageDisplay;
 }

 public void setHumanMessageDisplay(String humanMessageDisplay) {
  this.humanMessageDisplay = humanMessageDisplay;
 }
}

6. Enjoy playing with your ChatBot

Check out my source code as below

- Backend: https://github.com/vnnvanhuong/chatbot_rivescript_backend.git
- GUI: https://github.com/vnnvanhuong/chatbot_rivescript_gui.git

References:
[1]. http://science-technology.vn/?p=5761
[2]. https://www.rivescript.com/interpreters
[3]. https://github.com/aichaos/rivescript-java
[4]. https://youtu.be/wf8w1BJb9Xc
Labels:

Comments

Post a Comment

Popular posts from this blog

My must-have apps for daily work

There is no doubt that cool apps can help us be more productive and enjoyable at work. For the time being, I really love the following apps which are used by me almost every day. 1. A personal Kanban In fact, a personal kanban is the most useful app for me. Why does it matter? It is not just a to-do list, but it keeps me motivated every day because it helps me be able to know what my "big picture" is. I usually set up my plans together with a path to reach them.  KanbanFlow  is my preferred tool. KanbanFlow 2. A terminal Needless to say, a terminal is a must-have app for every developer, especially the ones use macOS/Linux. Due to its importance, I love to decorate and enhance it to be super exciting with various tools such as  iTerm ,  oh-my- zsh , and  thefuck . ;) iTerm + oh-my-zsh 3. A documentation "ecosystem" As a developer, I can not remember all things that I have experimented a day. Moreover, a document is really useful for sharing an...
Post a Comment
Read more

Regex - Check a text without special characters but German, French

Special characters such as square brackets ([ ]) can cause an exception " java.util.regex.PatternSyntaxException " or something like this if we don't handle them correctly. I had met this issue. In my case, my customers want our application should allow some characters in German and French even not allow some special characters. The solution is that we limit the allowed characters by showing the validation message on GUI. For an instance, the message looks like the following: "This field can't contain any special characters; only letters, numbers, underscores (_), spaces and single quotes (') are allowed." I used Regular Expression to check it. For entering Germany and French, I actually don't have this type of keyboard, so I referred these sites: * German characters: http://german.typeit.org/ * French characters: http://french.typeit.org/ Here is my code: package vn.nvanhuong.practice; import java.util.regex.Matcher; import java.util...
Post a Comment
Read more

Changing source code at run-time with Service Locator pattern

I have a service to get some data but the result can be different basing on where the implementation is. Technically, I have two or more concrete implementation of an interface and I am able to switch using these concrete classes at run-time. That means I have a place to configure it without re-deploying the application. In order to overcome this issue, I use Service Locator design pattern and here I only care about two advantages below: Encapsulating the specific implementation, we just declare the name and don't care about the implementation of the service. Changing the implementation at run-time. Client : an object that invokes the services via Service Locator Business services : services that is used by Client.
Post a Comment
Read more

My 2017 Review

Passion for System Design After finishing a one year project, my longest stable team (lasted for 3 years) was separated into two smaller teams. Sadly, but that was a good chance for me to become a key member in my new team. My preferred skills were about system architectures; therefore most of the tasks of building the application structures were handled by me. In order to enhance my design system skills, I have spent much my time for reading books closely after work. These following books help me a lot. - Object-Oriented Thought Process | Matt Weisfeld - Head First Design Pattern  | Elisabeth Freeman and Kathy Sierra - Java 8 in Action: Lambdas, Streams, and Functional-style Programming | Alan Mycroft and Mario Fusco Junior Technical Architect I was requested to join a technical architect team (aka Team. Alpha) where I actually had gained experiences almost on interviewing candidates for my company (lol). Besides, I noticed myself must improve the skills of convinci...
1 comment
Read more