Platform Events Developer Guide

Platform Events Developer Guide
Delivering Custom Notifications with Platform Events
Defining Your Custom Platform Event
Publishing Platform Events
Subscribing to Platform Events
Testing Your Platform Event in Apex
Encrypting Platform Event Messages at Rest in the Event Bus
Monitor Platform Event Publishing and Delivery Usage
Considerations
Examples
End-to-End Example Using Flows
Java Client Example
Java Client Example Using the Command Line
Prerequisites
Build and Run EMP Connector on the Command Line
Publish and Receive Platform Events
Java Client Example Using an IDE
Platform Event Samples
Reference
PDF

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Build and Run EMP Connector on the Command Line

Before you can run the EMP connector example, build the Java files.
  1. Get EMP Connector from GitHub. 
    1$ git clone https://github.com/forcedotcom/EMP-Connector.git
  2. Build the EMP Connector tool. 
    1$ cd EMP-Connector 
2$ mvn clean package
    The generated JAR file includes the connector and the DevLoginExample functionality. The shaded JAR contains all the dependencies for the connector, so downloading them separately isn’t necessary. The JAR file has a -phat Maven classifier.
  3. Subscribe to either a platform event or a custom channel. In this example, you subscribe to the Low_Ink__e platform event. Run this command after replacing the placeholder values.
    For <login_URL>, use one of these values.
    • My Domain login URL, including the https:// prefix: https://MyDomainName.my.salesforce.com
    • For sandbox without enhanced domains, use https://MyDomainName--SandboxName.my.salesforce.com.
    • For sandbox with enhanced domains, use https://MyDomainName--SandboxName.sandbox.my.salesforce.com.
    For <password>, append a security token to your password if you haven't set up a range of trusted IP addresses. For more information, see Reset Your Security Token and Set Trusted IP Ranges for Your Organization in Salesforce Help.
    For <channel>, specify /event/Low_Ink__e.

    The channel format for a custom platform event channel is /event/EventName__e, and for a standard platform event it’s /event/EventName. If instead you want to specify a custom channel, use /event/ChannelName__chn.

    1$ java -classpath target/emp-connector-0.0.1-SNAPSHOT-phat.jar com.salesforce.emp.connector.example.DevLoginExample <login_URL> <username> <password> <channel>
    • The Java command in this step uses the DevLoginExample.java class. To use EMP Connector with other classes, see the EMP Connector GitHub repo
    • Generally, don’t handle usernames and passwords of others when running code in production. In a production environment, delegate the login to OAuth. The BearerTokenExample.java class uses OAuth authentication.

    Note

Optionally, you can specify a replay option as the last argument. Valid values are:
  • –1: Get all new events sent after subscription. This option is the default.
  • –2: Get all new events sent after subscription and all past events within the retention window. Use -2 sparingly. If a large volume of event messages is stored, retrieving all event messages can slow performance.
  • Specific number: Get all events that occurred after the event with the specified replay ID.

The client is now subscribed to events. In the next step, publish some events and receive them in the client.