This section introduces how to develop and pacakge Java Pulsar functions to use on StreamNative cloud.

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Develop

StreamNative supports all features for the Java functions, please refer to: Develop Functions to learn how to develop a Java Function.

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Package

Please refer to: Pacakge Java Functions

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Deploy

After creating a cluster, set up your environment and develop&package your function, you can use the snctl, pulsarctl, pulsar-admin command, the REST API, or terraform to deploy a Pulsar function to your cluster. You can create a java Pulsar function by using a local JAR/NAR package or an uploaded Pulsar functions package(recommend).

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(Optional) Upload your function file to Pulsar

It’s recommend to upload your function file to Pulsar before you create a function. Since you can add a version suffix to the package.
Upload packages
snctl pulsar admin packages upload function://public/default/exclamation@v0.1 \
--path exclamation-1.0-SNAPSHOT.jar \
--description "exclamation function" \
--properties fileName=exclamation-1.0-SNAPSHOT.jar
You should see the following output:
The package 'function://public/default/exclamation@v0.1' uploaded from path 'examples/api-examples.jar' successfully

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Create

You need to package your Java function as a .jar or .nar file (and upload it to Pulsar) first. 
snctl pulsar admin functions create \
--tenant public \
--namespace default \
--name function1 \
--inputs persistent://public/default/test-java-input \
--output persistent://public/default/test-java-output \
--classname org.apache.pulsar.functions.api.examples.ExclamationFunction \
--jar function://public/default/exclamation@v0.1
--use-service-account
You should see something like this:
Created function1 successfully
For details about Pulsar function configurations, see Pulsar function configurations.

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What’s next?