Introduction

Streams applications can be developed in SPL, Python, and Java.  This article is a collection of resources to help you create operators or entire applications in Java.

The most common reason why you’d use Java to create your application is if you have existing Java code or libraries that you would like to use in your Streams application.¬† You can write a primitive Java operator that is invoked in your SPL composite or create your entire Streams application using only Java by using the Java Application API, or using the Apache Beam SDK.

Getting Started

If you are new to Streams and have not done so already, I recommend you read, at a minimum, the Basic Building Blocks section in the Streams Quick Start Guide to understand how Streams applications work.  For a deeper dive into Streams, you can also take the Streams course.

Then, pick the option that best suites your needs.

Options for using Java with Streams

Option 1: Create a Java primitive operator 

Choose this option if you want to create Java primitive operators that can be invoked from a SPL composite.

Option 2: Create Streams applications using only Java and/or Apache Beam.
If you want to create your applications using only Java, you have 2 choices:

Developing Java primitive operators

Streams Studio, the IDE for Streams, makes creating a Java operator very easy.  See how it is done in 1 minute in the following video:

Using the operator is also fairly simple, as shown in this next video:

There are several more videos in this series, see the Java Operator development guide for detailed information.

Debug and Performance for Java Operators

Problem Determination

Debugging a Java Operator: How to debug Java operators using the Eclipse Java Debugger?

Developing Streams applications using only Java

The streamsx.topology project on Github includes the Java Application API that allows you to create Streams applications using only Java. The advantage of this is that you do not have to learn SPL!  The toolkit is included in Streams but you can download the latest release from GitHub.

Samples

The streamsx.topology project includes samples that demonstrate how to perform common tasks.  These samples are included in the toolkit.

Read data from Kakfa, MQTT

Exchange data between streaming applications using publish/subscribe

Additional Resources

 

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