[JavaCro] Java Script (No, Not That One): Modern Automation with Java

We've all been there: you need a quick automation script, so you reach for Bash or Python and immediately get tripped up by syntax you can never remember. Or you try JavaScript and watch 5 + 3 quietly become "53". You want something fast, but you also want type safety and a language you actually know.

Good news: modern Java has become a real scripting language. Shebang support, single-file execution, and instance main methods mean no boilerplate and no build step—just a file you can run. When you need external libraries, JBang handles dependencies with a single line. And unlike a hastily typed shell script, the compiler still has your back before anything runs.

Through live demos, we'll go from a throwaway one-liner to genuinely useful scripts, using records and text blocks to keep them short and readable: parsing a CSV and calling an API, or building a self-contained tool your AI harness can invoke, returning typed, predictable output instead of best-effort text. All in Java, and all without a pom.xml in sight. You'll leave with a new tool for the jobs you currently hand off to Bash.

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1. JavaScript (No, Not That One) Modern Automation with Java @LoMagnette
2. #!/usr/bin/env bash a=5 b=3 result=$((a + b)) @LoMagnette
3. const addition = "11" + 1; const subtraction = "11" - 1; console.log(addition); console.log(subtraction); @LoMagnette
4. const addition = "11" + 1; const subtraction = "11" - 1; console.log(addition); console.log(subtraction); // 111 // 10 @LoMagnette
5. Loïc Magnette @LoMagnette https://lomagnette.github.io
6. @LoMagnette
7. 🐱 cat — concatenate files 🦇 bat — cat clone with syntax highlighting 🐟 fish — interactive shell 🐈 lynx — text-mode web browser 🦬 bison — GNU parser generator 🐜 ant — Apache Ant build tool 🐷 pig — Apache Pig Latin CLI (Hadoop) 🐦 crane / gcrane / krane — container registry management 🪿 goose — Go database migration tool 🥝 kiwi-ng — Linux system image builder 🦈 tshark — terminal packet capture/analysis (Wireshark's CLI sibling) 🦑 squid — caching proxy daemon 🐾 suricata — network IDS/IPS engine (named for the meerkat) 🐗 snort — network intrusion detection 🐅 tiger — Unix security auditing tool 🦅 falco — cloud-native runtime security monitor @LoMagnette 🦄 gunicorn — Python WSGI server ("Green Unicorn")
8. 🦑 squid — caching proxy daemon 🐾 suricata — network IDS/IPS engine (named for the meerkat) 🐗 snort — network intrusion detection 🐅 tiger — Unix security auditing tool 🦅 falco — cloud-native runtime security monitor 🦄 gunicorn — Python WSGI server ("Green Unicorn") 🦄 unicorn — Ruby app server 🐆 puma — Ruby web server 🦗 locust — load testing tool 🦎 geckodriver — WebDriver bridge for Firefox automation 🐇 hare — Hare language compiler 🐘 mahout — Apache Mahout ML CLI (elephant driver) 🦌 impala-shell — Apache Impala SQL shell 🐄 cowsay — ASCII cow says your text 🐮 cowthink — same, but a thought bubble 🐴 ponysay — ASCII pony version of cowsay 🐱 lolcat — rainbow-colors piped text @LoMagnette
9. 🦑 squid — caching proxy daemon 🐾 suricata — network IDS/IPS engine (named for the meerkat) 🐗 snort — network intrusion detection 🐅 tiger — Unix security auditing tool 🦅 falco — cloud-native runtime security monitor 🦄 gunicorn — Python WSGI server ("Green Unicorn") 🦄 unicorn — Ruby app server 🐆 puma — Ruby web server 🦗 locust — load testing tool 🦎 geckodriver — WebDriver bridge for Firefox automation 🐇 hare — Hare language compiler 🐘 mahout — Apache Mahout ML CLI (elephant driver) 🦌 impala-shell — Apache Impala SQL shell 🐄 cowsay — ASCII cow says your text 🐮 cowthink — same, but a thought bubble 🐴 ponysay — ASCII pony version of cowsay 🐱 lolcat — rainbow-colors piped text @LoMagnette
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15. 🐍 #!/usr/bin/env python3 print("Hello, World!") #!/usr/bin/env bash echo "Hello, World!" @LoMagnette
16. 🐍 #!/usr/bin/env python3 print("Hello, World!") #!/usr/bin/java --source 25 public class HelloWorld{ public static void main(String[] args){ System.out.println("Hello world"); } } @LoMagnette
17. 🐍 #!/usr/bin/env python3 print("Hello, World!") #!/usr/bin/java --source 25 void main(){ IO.println("Hello world"); } @LoMagnette
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25. • Parse args, run, exit • interactive shells / REPL • GraalVM native-image ready • Native tab-completion, history, • Spring, Micronaut, Quarkus • Larger, more established ecosystem line editing • Compile-time annotation processing • Faster startup
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31. Resources @LoMagnette https://lomagnette.github.io
32. Feedback @LoMagnette https://lomagnette.github.io