Create a Salesforce EventBus

Create a new Planform Event Object and give it a name App Metadata (App_Metadata__e) which will also be the name of the topic. Create some fields you that you would like to listen to. In Apex add the following event

Build event payload

  List<App_Metadata.BPUpdateAccounts> updatedAccountList = new List<App_Metadata.BPUpdateAccounts>();
  App_Metadata.BPUpdateAccounts updatedAccount = new App_Metadata.BPUpdateAccounts();
  updatedAccount.setId(financialAccount.Id);
  updatedAccount.add(updatedAccount);
  new App_Rest_Events(new App_Rest_Events.Event(UserInfo.getUserId(), App_Rest_Events.EventType.UPDATE_ACCOUNT, 
  updatedAccountList)).publishToEventBus();

Publish Event to eventBus

  public void publishToEventBus(){
    Object eventPayload = buildEventPayload();
    EventBus.publish(new App_Metadata__e(Metadata_Json__c=JSON.serialize(eventPayload)));
  }

Now let’s create our event listen to subscript to the topic and consume the messages from the EventBus.

Add the emp-connector jar to project

<repositories>
        <repository>
            <id>emp-connector</id>
            <url>${project.basedir}/lib/emp-connector-0.0.1-SNAPSHOT-phat.jar</url>
        </repository>
    </repositories>

....

<dependency>
     <groupId>com.salesforce.conduit</groupId>
     <artifactId>emp-connector</artifactId>
     <version>0.0.1-SNAPSHOT</version>
</dependency>

Create TopicSubscription to your event table by name

package com.app.salesforce.eventbus;

import com.salesforce.emp.connector.BayeuxParameters;
import com.salesforce.emp.connector.EmpConnector;
import com.salesforce.emp.connector.TopicSubscription;

import java.net.URL;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.function.Consumer;

import static com.salesforce.emp.connector.LoginHelper.login;

/**
 * Created by thysmichels on 5/15/17.
 */
public class SalesforceEventBus {

    private static final String SALESFORCE_USERNAME="salesforceUsername";
    private static final String SALESFORCE_PASSWORD="salesforcePassword";

    public static void main(String[] argv) throws Exception {

        long replayFrom = EmpConnector.REPLAY_FROM_EARLIEST;

        BayeuxParameters params;
        BayeuxParameters custom = getBayeuxParamWithSpecifiedAPIVersion("39.0");
        try {
            params = login(new URL("https://test.salesforce.com"),SALESFORCE_USERNAME, SALESFORCE_PASSWORD, custom);

        } catch (Exception e) {
            e.printStackTrace(System.err);
            System.exit(1);
            throw e;
        }

        Consumer<Map<String, Object>> consumer = event -> System.out.println(String.format("Received:\n%s", event));
        EmpConnector connector = new EmpConnector(params);

        connector.start().get(5, TimeUnit.SECONDS);

        TopicSubscription subscription = connector.subscribe("/event/App_Metadata__e", replayFrom, consumer).get(5, TimeUnit.SECONDS);

        System.out.println(String.format("Subscribed: %s", subscription));
    }


    private static BayeuxParameters getBayeuxParamWithSpecifiedAPIVersion(String apiVersion) {
        BayeuxParameters params = new BayeuxParameters() {

            @Override
            public String version() {
                return apiVersion;
            }

            @Override
            public String bearerToken() {
                return null;
            }

        };
        return  params;
    }
}

Topic receives response from subscribed channel

Subscribed: Subscription [/event/App_Metadata__e:-2]
Received:
{schema=D6-eSgLDrahnNjuNI52XAg, payload={CreatedById=00521000000UcF0, CreatedDate=2017-05-15T18:35:10Z, 
Metadata_Json__c="{\"accounts\":[{\"id\":\"28706236\",\"providerAccountId\":14736,\"sfId\":\"a0721000001A6fOAAS\"},
{\"id\":\"YL1111\",\"providerAccountId\":1466,\"sfId\":\"a0721000001A6fPAAS\"}],\"event\":\"UPDATE_GOAL\",\"linkAccounts\":null,
\"financialAccountMap\":null,\"goals\":[{\"id\":\"a0821000000OVPUAA4\",\"linkedAccounts\":[\"a0721000001ADqkAAG\"],
\"status\":\"In Progress\"},{\"id\":\"a0821000000OVPZAA4\",\"linkedAccounts\":null,\"status\":\"In Progress\"},{\"id\":\"a0821000000OVPeAAO\",\"linkedAccounts\":[\"a0721000001ADqaAAG\"],\"status\":\"In Progress\"}],
\"linkUserContext\":{\"accountList\":null,\"additionalProperties\":null,\"deleteAccountList\":null,\"email\":\"blah@email.com\",
\"password\":\"p@assw0rd\",
\"providerAccountIds\":null,\"sfClientId\":\"0033600000NO1QjAAL\",\"sfHouseholdId\":\"0013600000VNXflAAH\",\"sfUserId\":\"00521000000UcF0AAK\",
\"type\":\"YL\",\"username\":\"YL00F0A\"},\"priority\":5,\"providerAccounts\":null,
\"updatedAccounts\":null,\"updatedGoals\":[{\"id\":\"a0821000000OVPZAA4\",\"linkedAccounts\":null}],\"mapKeys\":{\"event\":\"event\",\"priority\":\"priority\",\"linkUserContext\":\"linkUserContext\",\"goals\":\"goals\",
\"accounts\":\"accounts\",\"providerAccounts\":\"providerAccounts\",\"updatedAccounts\":\"updatedAccounts\",\"updatedGoals\":
\"updatedGoals\",\"goalFinancialAccountMap\":\"goalFinancialAccountMap\",\"fastlinkAccounts\":\"fastlinkAccounts\"},
\"mapKeysFlag\":true,\"serializeNulls\":false}"}, event={replayId=1}}