B
Bouncy Castle
The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms, it was developed by the Legion of the Bouncy Castle, a registered Australian Charity, with a little help!
C
ClassGraph
https://github.com/classgraph/classgraph
ClassGraph is an uber-fast, ultra-lightweight, parallelized classpath scanner and module scanner for Java, Scala, Kotlin and other JVM languages.
commonmark-java
https://github.com/atlassian/commonmark-java
Java library for parsing and rendering Markdown text according to the CommonMark specification (and some extensions).
D
DCEVM
This project is a fork of original DCEVM project. The purpose of the project is to maintain enhanced class redefinition functionality for OpenJDK HotSpot 7/8 and Oracle JVM.
deeplearning4j
Deeplearning4j is the first commercial-grade, open-source, distributed deep-learning library written for Java and Scala. Integrated with Hadoop and Spark, DL4J is designed to be used in business environments on distributed GPUs and CPUs.
druid
https://github.com/alibaba/druid
Druid is the best database connection pool in JAVA. Druid provides powerful monitoring and extended functionality.
F
Fastjson
https://github.com/alibaba/fastjson
Fastjson is a Java library that can be used to convert Java Objects into their JSON representation.
J
jasmin
https://github.com/Sable/jasmin/
Jasmin is a Java Assembler Interface. It takes ASCII descriptions for Java classes, written in a simple assembler-like syntax, and using the Java Virtual Machine instruction set. It converts them into binary Java class files suitable for loading into a Java interpreter.
jsoup
jsoup is a Java library for working with real-world HTML. It provides a very convenient API for extracting and manipulating data, using the best of DOM, CSS, and jquery-like methods.
L
libphonenumber
https://github.com/googlei18n/libphonenumber
Google's common Java, C++ and JavaScript library for parsing, formatting, and validating international phone numbers.
P
Pollexor
https://github.com/square/pollexor
Java client for the Thumbor image service which allows you to build URIs in an expressive fashion using a fluent API.
S
Soot
Originally, Soot started off as a Java optimization framework. By now, researchers and practitioners from around the world use Soot to analyze, instrument, optimize and visualize Java and Android applications.