Java Resources

Various Java resources.

General

• Java Snippets - garbage collection tuning and other snippets.
• Fasterj
  • Garbage collectors overview
• Big-O summary for Java Collections Framework implementations?

Libraries

• Dagger - dependency injection.
• Guava
• Helidon
• Jackson - JSON and other data serialisation.
• Jdbi - SQL library.
• jOOQ - SQL library.
• Mockito - Mocking library.
• Netty HTTP - JAX-RS wrapper for Netty.
• Netty - network library.
• picocli - CLI handling.
• RxJava
• Reed-Solomon

Java 21

• Networking I/O with Virtual Threads - Under the hood

Java 17

• GC progress from JDK 8 to JDK 17

Java 8

• Java 8 Garbage Collection Tuning Guide

Reactive Programming

• ReactiveX
• RxJava
• Introduction to Rx
• RxJS Operator Decision Tree
• Project Reactor - which operator?
• Introduction to Rx
• RxJS Operator Decision Tree

Jackson

• Reading CSV with Jackson - cowtowncoder
• Writing CSV with Jackson - cowtowncoder

Thread Dumps

Basic thread dump:

jstack <pid>

However, this will only print stack traces from platform threads. To get vitual threads as well, use:

jcmd <pid> Thread.dump_to_file -overwrite threads.dump

Then just cat threads.dump to see it.

Flight Recorder

Instruct a running JVM to record for 60 seconds:

jcmd <pid> JFR.start duration=60s filename=flight.jfr

Copy file out of Docker container, if needed:

docker cp <containerId>:flight.jfr .

The file can be analysed with JDK Mission Control.