Tutorial: Introducing the Java Admin APIs

Follow along with the Tutorial Video.  It is part of your Hands-on Exercise.

We introduced the Java Admin APIs.

In pom.xml, link cluster_admin to sn_training.admin_tasks.ClusterAdmin.

<execution>
    <id>cluster_admin</id>
    <goals>
        <goal>java</goal>
    </goals>
    <configuration>
        <mainClass>sn_training.admin_tasks.ClusterAdmin</mainClass>
    </configuration>
</execution>

To view the schema of a topic, we use pulsarAdmin.schemas().getSchemaInfo(topic).

SchemaInfo si = null;
try{
    si = pulsarAdmin.schemas().getSchemaInfo(topic);
} catch (PulsarAdminException e) {
    e.printStackTrace();
}
System.out.println("Schema info: " + si);

To delete the schema of a topic, we use pulsarAdmin.schemas().deleteSchema(topic).

String topic = "persistent://student31/developer/order_approved";

try{
    pulsarAdmin.schemas().deleteSchema(topic);
} catch (PulsarAdminException e) {
    e.printStackTrace();
}

We deleted the registered schema for both orderBackLogChina and orderBackLogUS and confirmed OrderProducer is now able to write messages to the server with Schema Order.

Note: order_approved and order_declined still have a registered schema of String.

Note: there are still String messages in our topics.