org.apache.pulsar.functions.api.examples.CursorManagementFunction Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
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* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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package org.apache.pulsar.functions.api.examples;
import org.apache.pulsar.client.admin.PulsarAdmin;
import org.apache.pulsar.functions.api.Context;
import org.apache.pulsar.functions.api.Function;
/**
* A function that demonstrates how to use pulsar admin client exposed from
* Function Context. In this particular example, for every input message,
* the function do reset cursor of current function's subscription to a
* specified timestamp.
*/
public class CursorManagementFunction implements Function {
@Override
public String process(String input, Context context) throws Exception {
PulsarAdmin adminClient = context.getPulsarAdmin();
if (adminClient != null) {
String topic = context.getCurrentRecord().getTopicName().isPresent() ?
context.getCurrentRecord().getTopicName().get() : null;
String subName = context.getTenant() + "/" + context.getNamespace() + "/" + context.getFunctionName();
if (topic != null) {
// 1578188166 below is a random-pick timestamp
adminClient.topics().resetCursor(topic, subName, 1578188166);
return "reset cursor successfully";
}
}
return null;
}
}