Productivity, Sustainability, and Fun in modern Java

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Productivity, Sustainability, and Fun in modern Java Oleg Šelajev @shelajev

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Developer advocate atomicjar.com testcontainers.org

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Modern

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About Java releases 2 releases / year Oracle LTS every 4th release Multiple vendors GraalVM

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Text blocks

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Records

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instanceof pattern matching

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Switch expressions

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Pattern matching for switch

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Sealed classes

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Fast

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Startup Speed Peak Throughput JIT AOT Reduced Max Latency Low Memory Footprint Small Packaging

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Native Image Build Process Input: All classes from application, libraries, and VM Application Output: Native executable Points-to Analysis Ahead-of-Time Compilation Libraries Code in Text Section Run Initializations JDK Substrate VM Heap Snapshotting Iterative analysis until fixed point is reached Image Heap Writing Image Heap in Data Section

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Configuring Native Image build: Reflection, Proxies, JNI, Resources, etc https://medium.com/graalvm/working-with-native-image-efficiently-c512ccdcd61b

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Configuring Native Image build: Reflection, Proxies, JNI, Resources, etc java -agentlib:native-image-agent=\ config-output-dir=META-INF/native-image \ -jar App.jar https://medium.com/graalvm/working-with-native-image-efficiently-c512ccdcd61b

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https://medium.com/graalvm/graalvm-21-3-is-here-java-17-native-image-performance-updates-and-more-ac4cbafcfc05

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Build tools • sbt native client • • • https://www.scala-sbt.org/1.x/docs/sbt-1.4-Release-Notes.html https://asciinema.org/a/wAAYjiO0TNW0V7dCSebMQB5wa mvnd • https://github.com/mvndaemon/mvnd

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GraalVM Native Image Support in the AWS SDK for Java 2.x The test application creates an S3Client with ApacheHttpClient and sends a simple GetObjectRequest. In our testing, we measured the SDK 2.x startup time and the first request latency as well as the memory usage. https://aws.amazon.com/blogs/developer/graalvm-native-image-support-in-the-aws-sdk-for-java-2-x/

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Writing Kubectl plugins with Scala or Java, with Fabric8 Kubernetes client on GraalVM Rewriting a kubectl plugin from a standard Go stack to a more comfortable approach with Scala has been challenging and rewarding. We are really happy with the result, and we arguably improved it in several ways. https://www.lightbend.com/blog/writing-kubectl-plugins-with-scala-or-java-with-fabric8-kubernetes-client-on-graalvm