SlackBot in Java

MessageListener.java

package edu.sjsu.amigo.slackbot;

import com.ullink.slack.simpleslackapi.SlackChannel;
import com.ullink.slack.simpleslackapi.SlackSession;
import com.ullink.slack.simpleslackapi.SlackUser;
import com.ullink.slack.simpleslackapi.events.SlackMessagePosted;
import com.ullink.slack.simpleslackapi.impl.SlackSessionFactory;
import com.ullink.slack.simpleslackapi.listeners.SlackMessagePostedListener;
import edu.sjsu.amigo.mp.kafka.Message;
import edu.sjsu.amigo.mp.kafka.MessageProducer;
import edu.sjsu.amigo.mp.kafka.SlackMessage;
import edu.sjsu.amigo.mp.util.JsonUtils;

import java.io.IOException;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;


/**
 * Listens to messages sent on channels amigo chatbot joined on slack or messges sent directly to it.
 *
 * @author rwatsh on 2/26/17.
 */
public class MessageListener {
    private final static Logger logger = Logger.getLogger(MessageListener.class.getName());
    /**
     * This method shows how to register a listener on a SlackSession
     */
    public void registerListener(SlackSession session)
    {
        // first define the listener
        SlackMessagePostedListener messagePostedListener = new SlackMessagePostedListener()
        {
            public void onEvent(SlackMessagePosted event, SlackSession session)
            {
                SlackChannel channelOnWhichMessageWasPosted = event.getChannel();
                String messageContent = event.getMessageContent();
                SlackUser messageSender = event.getSender();
                SlackChannel channel = event.getChannel();
                logger.info("Received message from " + messageSender + " content [" + messageContent + "]");

                if (isNotNullOrEmpty(messageContent)) {

                    processUserMessage(messageContent, messageSender, session, channel);

                }
            }
        };
        //add it to the session
        session.addMessagePostedListener(messagePostedListener);

        //that's it, the listener will get every message post events the bot can get notified on
        //(IE: the messages sent on channels it joined or sent directly to it)
    }

    private void processUserMessage(String messageContent, SlackUser messageSender, SlackSession session, SlackChannel channel) {
        // TODO change it to be processed asynchronously
        // Parse the message content
        String parsedMessage = parseMessage(messageContent);

        if (parsedMessage != null) {
            // Respond to user that we are working on it...
            String reply = "Working on it...";
            if (channel != null) {
                session.sendMessage(channel, reply);
            } else {
                session.sendMessageToUser(messageSender, reply, null);
            }


            // TODO Get the intent from wit.ai here...
            String intent = parsedMessage;

            // Construct the message in JSON
            String currentTime = "" + (new Date()).getTime();

            Message msg = new SlackMessage(currentTime, messageSender.getUserMail(), messageSender.getUserName(),
                    parsedMessage, intent, channel.getId(), System.getenv("SLACK_BOT_TOKEN"));

            String msgJson = null;

            try {
                msgJson = JsonUtils.convertObjectToJson(msg);
            } catch (IOException e) {
                logger.log(Level.SEVERE, "Error in converting message to JSON", e);
            }

            if (msgJson != null) {
                // Send message to topic on kafka MQ
                logger.info("Sending message as JSON: " + msgJson);
                try (MessageProducer producer = new MessageProducer()) {
                    producer.sendUserMessage(msgJson);
                } catch (Exception e) {
                    logger.log(Level.SEVERE, "Error in publishing message to queue", e);
                }
            }
        }
    }

    private boolean isNotNullOrEmpty(String messageContent) {
        return messageContent != null && !messageContent.trim().isEmpty();
    }

    /**
     * Parse the message to see if content includes <@BOT_ID> in the message.
     * If it does, the message was meant for our chatbot hence get the message after the @BOT_ID.
     *
     * @param messageContent
     * @return
     */
    private String parseMessage(String messageContent) {
        String botId = "<@" + System.getenv("BOT_ID") + ">";
        String parsedMessage = null;
        if (messageContent.contains(botId)) {
            // Get the text after <@BOT_ID> for example, from "@amigo aws iam list-users" get "aws iam list-users".
            parsedMessage = messageContent.split(botId)[1];
        }
        return parsedMessage;
    }

    public static void main(String[] args) throws IOException
    {
        SlackSession session = SlackSessionFactory.createWebSocketSlackSession(System.getenv("SLACK_BOT_TOKEN"));
        session.connect();
        MessageListener listener = new MessageListener();
        listener.registerListener(session);
    }

}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <artifactId>slackbot-service</artifactId>

    <dependencies>
        <dependency>
            <groupId>edu.sjsu</groupId>
            <artifactId>mq-common</artifactId>
            <version>${project.version}</version>
        </dependency>
        <dependency>
            <groupId>com.ullink.slack</groupId>
            <artifactId>simpleslackapi</artifactId>
            <version>${simple-slack-api.version}</version>
        </dependency>
    </dependencies>
    <properties>
        <simple-slack-api.version>0.6.0</simple-slack-api.version>
        <maven-compiler-plugin.source>1.8</maven-compiler-plugin.source>
    </properties>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.3</version>
                <configuration>
                    <source>${maven-compiler-plugin.source}</source>
                    <target>${maven-compiler-plugin.source}</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.18.1</version>
                <configuration>
                    <suiteXmlFiles>
                        <suiteXmlFile>testng.xml</suiteXmlFile>
                    </suiteXmlFiles>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>2.3</version>
                <configuration>
                    <createDependencyReducedPom>true</createDependencyReducedPom>
                    <filters>
                        <filter>
                            <artifact>*:*</artifact>
                            <excludes>
                                <exclude>META-INF/*.SF</exclude>
                                <exclude>META-INF/*.DSA</exclude>
                                <exclude>META-INF/*.RSA</exclude>
                            </excludes>
                        </filter>
                    </filters>
                </configuration>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <transformers>
                                <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <mainClass>edu.sjsu.amigo.slackbot.MessageListener</mainClass>
                                </transformer>
                            </transformers>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>

    </build>
</project>