Yawkat

My name is Jonas Konrad. I grew up in Münster, NRW, Germany, and got my Master's in computer science at the Friedrich-Alexander Universität Erlangen-Nürnberg.

My main focus is development on the JVM. My other big interest is IT security, including cryptography, reverse engineering and application security. Through my work I have also learned computer networking and systems administration.

e-mail

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Twitter

@yawkat

Mastodon

@yawkat@infosec.exchange

• GitHub
• Jenkins

Articles ¶

I am active in Freenode/##java and have written a few articles on Java topics:

• Reversing the fanfiction.net Android App (June 2018)
• An introduction to java.time (April 2018)
• Java Support Lifecycle (April 2018) on the future of Java support
• How (not) to extend standard collection classes (October 2017), on why you should not extend standard collection classes.
• Immutability in Java (April 2017), an overview of immutability implementation in java and avoiding common pitfalls.
• Bypassing subclass method overrides (May 2015) on using the MethodHandle API to invoke an overridden method's supermethod.

Open-Source Projects ¶

Over the years, I have built and contributed to many open-source projects. Most of that work is available on GitHub. This list is a showcase of contributions to large or well-known projects.

Own Projects

• code.yawk.at

  Java source code browser written using kotlin, undertow, jdbi and postgresql (GitHub).

• javap.yawk.at

  Web UI for javap written using kotlin, dropwizard, guice, jdbi and jquery (GitHub).

• katbot

  IRC Bot written using kotlin and KittehIRCClientLib.

Contributions

• jackson-datatype-eclipse-collections

  I am the author and maintainer of the Jackson module for Eclipse Collections.

• jackson-dataformat-toml

  I am the author and maintainer of the Jackson module for TOML.
• Minor contributions to Netty, JSoup, ASM, radare2, jackson-dataformat-cbor.

Long-Term Projects ¶

1. Oracle Labs ¶ 2021 -

   Working on Micronaut.

2. Master's Thesis: Isolating on-the-fly Hypervisors against DMA using Intel VT-d ¶ 2020

   Implementation of hypervisor IOMMU protection as part of the hyperleech project.

   • C, Go
   • Intel VT-d

3. Bachelor's Thesis: Valda IR ¶ 2018

   A new intermediate representation for DEX.

   • Java, Kotlin
   • Android
   • Smali

4. CubeCraft PE ¶ 2015 - 2017

   Project developed for CubeCraft.

   • Java, Kotlin
   • Guice
   • Netty
   • Minecraft Pocket Edition (protocol work)

5. Bluestart ¶ 2015 - 2016

   Management service for user-configurable private Minecraft servers. Developed for PhanaticMC.

   • Java
   • Spring, Spring MVC (spring-web, spring-security, spring-data-jpa)
   • GWT
   • REST
   • HTML / CSS
   • Docker

6. Saikban ¶ 2015 - 2016

   Minecraft ban manager with web interface, developed for PhanaticMC.

   • Java
   • BungeeCord
   • Spring, Spring MVC (spring-web, spring-security)
   • SQL with Hibernate (JPA)
   • handlebars.java
   • HTML / CSS / JavaScript / Bootstrap

7. Cricket ¶ 2014 - 2016

   Minecraft ticketing system with web interface, developed for PhanaticMC.

   • Java
   • Bukkit / Spigot
   • SQL
   • handlebars.java
   • HTML / CSS / JavaScript / Bootstrap

8. MCStrike ¶ 2012 - 2014

   Minecraft minigame server

   • Java
   • Minecraft server code
   • Bukkit / Spigot
   • ProtocolLib
   • BungeeCord, including multi-machine bungee installations and numerous contributions
   • Netty
   • MongoDB
   • Bash (for server management)
   • Python (for server management)

9. jClient ¶ 2011 - 2013

   A minecraft mod.

   • Java
   • Minecraft client code
   • GL (via LWJGL)