A curated list of awesome Java frameworks, libraries and software.
- Awesome Java
- Bytecode Manipulation
- Cluster Management
- Code Analysis
- Constraint Satisfaction Problem Solver
- Continuous Integration
- Data structures
- Date and Time
- Dependency Injection
- Distributed Applications
- Distributed Databases
- Document Processing
- Functional Programming
- Game Development
- High Performance
- JVM and JDK
- Machine Learning
- Natural Language Processing
- Reactive libraries
- REST Frameworks
- Template Engine
- Web Crawling
- Web Frameworks
In existence since the beginning of time and wich will continue being used long after the hype has waned.
- Apache Ant - Build process management with XML.
- cglib - Bytecode generation library.
- GlassFish - Application server and reference implementation for Java EE sponsored by Oracle.
- Hudson - Continuous integration server still in active development.
- JavaServer Faces - Oracle’s open-source implementation of the JSF standard, Mojarra.
- JavaServer Pages - Common templating for websites with custom tag libraries.
- Liquibase - Database-independent library for tracking, managing and applying database schema changes.
Tools which handle the buildcycle and dependencies of an application.
- Apache Maven - Declarative build and dependency management which favors convention over configuration. It might be preferable to Apache Ant which uses a rather procedural approach and can be difficult to maintain.
- Bazel - Build tool from Google that builds code quickly and reliably.
- Gradle - Incremental builds which are programmed via Groovy instead of declaring XML. Works well with Maven’s dependency management.
Libraries to manipulate bytecode programmatically.
- ASM - All purpose, low level, bytecode manipulation and analysis.
- Byte Buddy - Further simplifies bytecode generation with a fluent API.
- Javassist - Tries to simplify the editing of bytecode.
Frameworks which can dynamically manage applications inside of a cluster.
- Apache Aurora - Apache Aurora is a Mesos framework for long-running services and cron jobs.
- Singularity - Singularity is a Mesos framework that makes deployment and operations easy. It supports web services, background workers, scheduled jobs, and one-off tasks.
Tools that provide metrics and quality measurements.
- Checkstyle - Static analysis of coding conventions and standards.
- Error Prone - Catches common programming mistakes as compile-time errors.
- FindBugs - Static analysis of bytecode to find potential bugs.
- jQAssistant - Static code analysis with Neo4J-based query language.
- PMD - Source code analysis for finding bad coding practices.
- SonarQube - Integrates other analysis components via plugins and provides an overview of the metrics over time.
Frameworks that help to create parsers, interpreters or compilers.
- ANTLR - Complex full-featured framework for top-down parsing.
- JavaCC - More specific and slightly easier to learn. Has syntactic lookahead.
Libraries that provide external configuration.
Constraint Satisfaction Problem Solver
Libraries that help on implementing optimization and satisfiability problems.
- Choco - Off-the-shelf constraint satisfaction problem solver, which uses constraint programming techniques.
- JaCoP - Includes an interface for the FlatZinc language, enabling it to execute MiniZinc models.
- OptaPlanner - Business planning and resource scheduling optimization solver.
- Sat4J - State-of-the-art SAT solver for boolean and optimization problems.
Tools which support continuously building, testing and releasing applications.
- Bamboo - Atlassian’s solution with good integration of their other products. You can either apply for an open-source license or buy it.
- CircleCI - Hosted service with a free trial.
- Codeship - Hosted services with a limited free plan.
- fabric8 - Integration platform for containers.
- Go - ThoughtWork’s open-source solution.
- Jenkins - Provides server-based deployment services.
- TeamCity - JetBrain’s CI solution with a free version.
- Travis - Hosted service often used for open-source projects.
Frameworks and libraries that simplify reading/writing CSV data.
- uniVocity-parsers - One of the fastest and most feature-complete CSV. Also comes with parsers for TSV and fixed width records.
Everything which simplifies interactions with the database.
- Apache Phoenix - High performance relational database layer over HBase for low latency applications.
- Crate - Distributed data store that implements data synchronization, sharding, scaling, and replication. In addition, it provides a SQL-based syntax to execute queries across a cluster.
- Flyway - Simple database migration tool.
- H2 - Small SQL Database notable for its in-memory functionality.
- HikariCP - High performance JDBC connection pool.
- JDBI - Convenient abstraction of JDBC.
- jOOQ - Generates typesafe code based on SQL schema.
- MapDB - Embedded database engine that provides concurrent collections backed on disk or in off-heap memory.
- Presto - Distributed SQL query engine for big data.
- Querydsl - Typesafe unified queries.
Efficient and specific data structures.
- Apache Parquet - Columnar storage format based on assembly algorithms from the Dremel paper by Google.
- Protobuf - Google’s data interchange format.
- SBE - Simple Binary Encoding, one of the fastest message formats around.
- Wire - Clean, lightweight protocol buffers.
Date and Time
Libraries related to handling date and time.
- Joda-Time - De facto standard date/time-library before Java 8.
- Time4J - Advanced date and time library.
Libraries that help to realize the Inversion of Control paradigm.
- Apache DeltaSpike - CDI extension framework.
- Dagger2 - Compile-time injection framework without reflection.
- Guice - Lightweight but powerful framework that completes Dagger.
- HK2 - Light-weight and dynamic dependency injection framework.
Augmentation of the development process at a fundamental level.
- ADT4J - JSR-269 code generator for algebraic data types.
- AspectJ - Seamless aspect-oriented programming extension.
- Auto - Collection of source code generators.
- DCEVM - Modification of the JVM that allows unlimited redefinition of loaded classes at runtime.
- HotswapAgent - Unlimited runtime class and resource redefinition.
- Immutables - Scala-like case classes.
- JHipster - Yeoman source code generator to create applications based on Spring Boot and AngularJS.
- JRebel - Commercial software that instantly reloads code and configuration changes without redeploys.
- Lombok - Code-generator which aims to reduce the verbosity.
- Spring Loaded - Class reloading agent.
- vert.x - Polyglot event-driven application framework.
Libraries and frameworks for writing distributed and fault-tolerant applications.
- Akka - Toolkit and runtime for building concurrent, distributed, and fault tolerant event-driven applications.
- Apache Storm - Realtime computation system.
- Apache ZooKeeper - Coordination service with distributed configuration, synchronization, and naming registry for large distributed systems.
- Hazelcast - Highly scalable in-memory datagrid.
- Hystrix - Provides latency and fault tolerance.
- JGroups - Toolkit for reliable messaging and creating clusters.
- Orbit - Virtual Actors, adding another level of abstraction to traditional actors.
- Quasar - Lightweight threads and actors for the JVM.
Databases in a distributed system that appear to applications as a single data source.
- Apache Cassandra - Column-oriented and providing high availability with no single point of failure.
- Apache HBase - Hadoop database for big data.
- Druid - Real-time and historical OLAP data store that excel at aggregation and approximation queries.
- Infinispan - Highly concurrent key/value datastore used for caching.
Tools which handle the distribution of applications in native formats.
- Bintray - Version control for binaries which handles the publishing. Can also be used with Maven or Gradle and has a free plan for open-source software or several business plans.
- Central Repository - Largest binary component repository available as a free service to the open-source community. Default used by Apache Maven and available in all other build tools.
- IzPack - Setup authoring tool for cross-platform deployments.
- JitPack - Easy to use package repository for GitHub. Builds Maven/Gradle projects on demand and publishes ready-to-use packages.
- Launch4j - Wraps JARs in lightweight and native Windows executables.
- Nexus - Binary management with proxy and caching capabilities.
- packr - Packs JARs, assets and the JVM for native distribution on Windows, Linux and Mac OS X.
Libraries that assist with processing office document formats.
- Apache POI - Supports OOXML (XLSX, DOCX, PPTX) as well as OLE2 (XLS, DOC or PPT).
- documents4j - API for document format conversion using third-party converters such as MS Word.
- jOpenDocument - Processes the OpenDocument format.
Libraries that facilitate functional programming.
- Cyclops - Monad and stream utilities, comprehensions, pattern matching, trampolines and much more.
- Fugue - Functional extensions to Guava.
- Functional Java - Implements numerous basic and advanced programming abstractions that assist composition-oriented development.
- Javaslang - Functional component library that provides persistent data types and functional control structures.
- jOOλ - Extension to Java 8 which aims to fix gaps in lambda, providing numerous missing types and a rich set of sequential Stream API additions.
Frameworks that support the development of games.
- jMonkeyEngine - Game engine for modern 3D development.
- libGDX - All-round cross-platform, high-level framework.
- LWJGL - Robust framework that abstracts libraries like OpenGL/CL/AL.
Libraries to create modern graphical user interfaces.
Everything about high performance computation, from collections to specific libraries.
- Agrona - Data structures and utility methods that are common in high-performance applications.
- Disruptor - Inter-thread messaging library.
- fastutil - Fast and compact type-specific collections.
- GS Collections - Collection framework inspired by Smalltalk.
- HPPC - Primitive collections.
- Javolution - Library for real-time and embedded systems.
- JCTools - Concurrency tools currently missing from the JDK.
- Koloboke - Hash sets and hash maps.
- Trove - Primitive collections.
Integrated development environments that try to simplify several aspects of development.
- Eclipse - Established, open-souce project with support for lots of plugins and languages.
- IntelliJ IDEA - Supports a lot of JVM languages and provides good options for Android development. The commercial edition targets the enterprise sector.
- NetBeans - Provides integration for several Java SE and EE features from database access to HTML5.
Libraries that assist with the creation, evaluation or manipulation of graphical images.
- Imgscalr - Simple and efficient hardware-accelerated image-scaling library implemented in pure Java 2D.
- Picasso - Image downloading and caching library for Android.
- Thumbnailator - Thumbnailator is a high-quality thumbnail generation library for Java.
- ZXing - Multi-format 1D/2D barcode image processing library.
Libraries that simplify JSON processing.
- Genson - Powerful and easy to use Java to JSON conversion library.
- Gson - Serializes objects to JSON and vice versa. Good performance with on-the-fly usage.
- Jackson - Similar to GSON but has performance gains if you need to instantiate the library more often.
- LoganSquare - JSON parsing and serializing library based on Jackson’s streaming API. Outpeforms GSON & Jackson’s library.
JVM and JDK
Current implementations of the JVM/JDK.
Languages other than Java that can be used to write JVM applications.
- Scala - Statically typed programming language that fuses the object - oriented model and functional programming ideas.
- Groovy - Optionally typed and dynamic language, with static-typing and static compilation capabilities. Currently an incubating Apache project
- Clojure - Dynamically typed programming language that can be seen as a modern take on Lisp.
- Ceylon - Statically typed object-oriented language developed by RedHat.
- Kotlin - JetBrain’s statically typed programming language for the JVM, Android and the browser.
Libraries that log the behavior of an application.
- Apache Log4j 2 - Complete rewrite with a powerful plugin and configuration architecture.
- kibana - Analyzes and visualizes log files.
- Logback - Robust logging library with interesting configuration options via Groovy.
- logstash - Tool for managing log files.
- Metrics - Expose metrics via JMX or HTTP and can send them to a database.
- SLF4J - Abstraction layer which is to be used with an implementation.
Tools that provide specific statistical algorithms which allow learning from data.
- Apache Flink - Fast and reliable large-scale data processing engine.
- Apache Hadoop - Storage and large-scale processing of data-sets on clusters of commodity hardware.
- Apache Mahout - Scalable algorithms focused on collaborative filtering, clustering and classification.
- Apache Spark - Data analytics cluster computing framework.
- DeepDive - Creates structured information from unstructured data and integrates it into an existing database.
- Deeplearning4j - Distributed and multi-threaded deep learning library.
- H2O - Analytics engine for statistics over big data.
- Weka - Collection of algorithms for data mining tasks ranging from pre-processing to visualization.
Tools that help to send messages between clients in order to ensure protocol independency.
- Aeron - Efficient reliable unicast and multicast message transport.
- Apache ActiveMQ - Message broker that implements JMS and converts synchronous to asynchronous communication.
- Apache Camel - Glues together different transport APIs via Enterprise Integration Patterns.
- Apache Kafka - High-throughput distributed messaging system.
- Hermes - Fast and reliable message broker built on top of Kafka.
- JBoss HornetQ - Clear, concise, modular and made to be embedded.
- JeroMQ - Implementation of ZeroMQ.
- Smack - Cross-platform XMPP client library.
- Design Patterns - Implementation and explanation of the most common design patterns.
- Jimfs - In-memory file system.
- Lanterna - Easy console text GUI library similar to curses.
- LightAdmin - Pluggable CRUD UI library for rapid application development.
- OpenRefine - Tool for working with messy data: cleaning, transforming, extending it with web services and linking it to databases.
- RoboVM - Commercial framework with a free trial to write native iOS apps.
Tools that monitor applications in production.
- AppDynamics - Commercial performance monitor.
- JavaMelody - Performance monitoring and profiling.
- Kamon - Tool for monitoring applications running on the JVM.
- New Relic - Commercial performance monitor.
- SPM - Commercial performance monitor with distributing transaction tracing for JVM apps.
- Takipi - Commercial in-production error monitoring and debugging.
For working with platform-specific native libraries.
- JNA - Work with native libraries without writing JNI. Also provides interfaces to common system libraries.
Natural Language Processing
Libraries that specialize on processing text.
- Apache OpenNLP - Toolkit for common tasks like tokenization.
- CoreNLP - Stanford’s CoreNLP provides a set of fundamental tools for tasks like tagging, named entity recognition, sentiment analysis and many more.
- LingPipe - Toolkit for a variety of tasks ranging from POS tagging to sentiment analysis.
- Mallet - Statistical natural language processing, document classification, clustering, topic modeling and more.
Libraries for network programming.
- Async Http Client - Asynchronous HTTP and WebSocket client library.
- Grizzly - NIO framework. Used as a network layer in Glassfish.
- Netty - Framework for building high performance network applications.
- OkHttp - HTTP+SPDY client.
- Undertow - Web server providing both blocking and non-blocking API’s based on NIO. Used as a network layer in WildFly.
APIs which handle the persistence of objects.
- Ebean - Provides simple and fast data access.
- EclipseLink - Supports a number of persistence standards: JPA, JAXB, JCA and SDO.
- Hibernate - Robust and widely used with an active community.
- MyBatis - Couples objects with stored procedures or SQL statements.
- OrmLite - Lightweight package avoiding the complexity and overhead of other ORM products.
Everything that helps with the creation of PDF files.
- Apache FOP - Creates PDF from XSL-FO.
- Apache PDFBox - Toolbox for creating and manipulating PDF.
- DynamicReports - Simplifies JasperReports.
- flyingsaucer - XML/XHTML and CSS 2.1 renderer.
- iText - Creates PDF files programmatically but requires a license for commercial purposes.
- JasperReports - Complex reporting engine.
Tools for performance analysis, profiling and benchmarking.
- jHiccup - Logs and records platform JVM stalls.
- JMH - Microbenchmarking tool for the JVM.
- JProfiler - Commercial profiler.
- LatencyUtils - Utilities for latency measurement and reporting.
- VisualVM - Visual interface for detailed information about running applications.
- YourKit Java Profiler - Commercial profiler.
Libraries for developing reactive applications.
- Reactive Streams - Provide a standard for asynchronous stream processing with non-blocking backpressure.
- Reactor - Library for building reactive fast-data applications.
- RxJava - Library for composing asynchronous and event-based programs using observable sequences from the JVM.
Frameworks specifically for creating RESTful services.
- Dropwizard - Opinionated framework for setting up modern web applications with Jetty, Jackson, Jersey and Metrics.
- Feign - HTTP client binder inspired by Retrofit, JAXRS-2.0, and WebSocket.
- Jersey - JAX-RS reference implementation.
- RESTEasy - Fully certified and portable implementation of the JAX-RS specification.
- RestExpress - Thin wrapper on the JBOSS Netty HTTP stack to provide scaling and performance.
- RestX - Framework based on annotation processing and compile-time source generation.
- Retrofit - Type-safe REST client.
- Spark - Sinatra inspired framework.
- Swagger - Swagger is a specification and complete framework implementation for describing, producing, consuming, and visualizing RESTful web services.
Libraries for scientific computing and analysis.
- DataMelt - Environment for scientific computation, data analysis and data visualization.
- JGraphT - Graph library that provides mathematical graph-theory objects and algorithms.
- JScience - Provides a set of classes to work with scientific measurements and units.
Engines which index documents for search and analysis.
- Apache Solr - Enterprise search engine optimized for high volume traffic.
- Elasticsearch - Distributed, multitenant-capable full-text search engine with a RESTful web interface and schema-free JSON documents.
Libraries that handle security, authentication, authorization or session management.
- Apache Shiro - Performs authentication, authorization, cryptography and session management.
- Bouncy Castle - All-purpose cryptographic library. JCA provider, wide range of functions from basic helpers to PGP/SMIME operations.
- Cryptomator - Multiplatform transparent client-side encryption of files in the cloud.
- Keycloak - Integrated SSO and IDM for browser apps and RESTful web services.
- PicketLink - Umbrella project for security and identity management.
Libraries that handle serialization with high efficiency.
- FlatBuffers - Memory efficient serialization library that can access serialized data without unpacking and parsing it.
- Kryo - Fast and efficient object graph serialization framework.
- FST - JDK compatible high performance object graph serialization.
- MessagePack - Efficient binary serialization format.
Servers which are specifically used to deploy applications.
- Apache Tomcat - Robust all-round server for Servlet and JSP.
- Apache TomEE - Tomcat plus Java EE.
- Jetty - Lightweight, small server, often embedded in projects.
- WebSphere Liberty - Lightweight, modular server developed by IBM
- WildFly - Formerly known as JBoss and developed by Red Hat with extensive Java EE support.
Tools which substitute expressions in a template.
- Apache Velocity - Templates for HTML pages, emails or source code generation in general.
- FreeMarker - General templating engine without any heavyweight or opinionated dependencies.
- Handlebars.java - Logic-less and semantic Mustache templates.
- Thymeleaf - Aims to be a substitute for JSP and works for XML files in general.
Tools that test from model to the view.
- Apache JMeter - Functional testing and performance measurements.
- Arquillian - Integration and functional testing platform for Java EE containers.
- AssertJ - Fluent assertions that improve readability.
- Awaitility - DSL for synchronizing asynchronous operations.
- Cucumber - BDD testing framework.
- Gatling - Load testing tool designed for ease of use, maintainability and high performance.
- Hamcrest - Matchers that can be combined to create flexible expressions of intent.
- JMockit - Mocks static, final methods and more.
- JUnit - Common testing framework.
- Mockito - Creation of test double objects in automated unit tests for the purpose of TDD or BDD.
- PowerMock - Enables mocking of static methods, constructors, final classes and methods, private methods and removal of static initializers.
- REST Assured - Java DSL for easy testing for REST/HTTP services.
- Selenide - Concise API around Selenium to write stable and readable UI tests.
- Selenium - Portable software testing framework for web applications.
- Spock - JUnit-compatible framework featuring an expressive Groovy-derived specification language.
- TestNG - Testing framework.
- Truth - Google’s assertion and proposition framework.
- Unitils - Modular testing library for unit and integration testing.
- WireMock - Stubbs and mocks web services.
Libraries which provide general utility functions.
- Apache Commons - Provides different general purpose functions like configuration, validation, collections, file upload or XML processing.
- args4j - Command line arguments parser.
- CRaSH - Provides a CLI for running processes.
- Gephi - Cross-platform for visualizing and manipulating large graph networks.
- Guava - Collections, caching, primitives support, concurrency libraries, common annotations, string processing, I/O, and so forth.
- JADE - Framework and environment for building and to debugging multi-agent systems.
- javatuples - Tuples.
- JCommander - Command line arguments parser.
- Protégé - Provides an ontology editor and a framework to build knowledge-based systems.
Libraries that analyze the content of websites.
- Apache Nutch - Highly extensible, highly scalable web crawler for production environment.
- Crawler4j - Simple and lightweight web crawler.
- JSoup - Scrapes, parses, manipulates and cleans HTML.
Frameworks that handle the communication between the layers of an web application.
- Apache Tapestry - Component-oriented framework for creating dynamic, robust, highly scalable web applications.
- Apache Wicket - Component-based web application framework similar to Tapestry with a stateful GUI.
- Grails - Groovy framework with the aim to provide a highly productive environment by favoring convention over configuration, no XML and support for mixins.
- Ninja - Full stack web framework.
- Pippo - Small, highly modularized Sinatra-like framework.
- Play - Uses convention over configuration, hot code reloading and display of errors in the browser.
- PrimeFaces - JSF framework which has a free and a commercial version with support. Provides several frontend components.
- Ratpack - Set of libraries that facilitate fast, efficient, evolvable and well tested HTTP applications.
- Spring Boot - Microframework which simplifies the development of new Spring applications.
- Spring - Provides many packages ranging from dependency injection to aspect-oriented programming to security.
- Vaadin - Event-driven framework build on top of GWT. Uses server-side architecture with Ajax on the client-side.
- r/java - Subreddit for the Java community.
- stackoverflow - Question/answer platform.
- vJUG - Virtual Java User Group.
Books that had a high impact and are still worth reading.
Something to listen to while programming.
Active accounts to follow. Descriptions from Twitter.
- Adam Bien - Freelancer: Author, JavaONE Rockstar Speaker, Consultant, Java Champion.
- Aleksey Shipilëv - Performance Geek, Benchmarking Tzar, Concurrency Bug Hunter.
- Antonio Goncalves - Java Champion, JUG Leader, Devoxx France, Java EE 6⁄7, JCP, Author.
- Arun Gupta - Java Champion, JavaOne Rockstar, UG Leader, Devoxx4Kids-er, Red Hatter.
- Brian Goetz - Java Language Architect at Oracle.
- Bruno Borges - Product Manager/Java Jock at Oracle.
- Ed Burns - Consulting Member of the Technical Staff at Oracle.
- Eugen Paraschiv - Author of the Spring Security Course.
- James Weaver - Java/JavaFX/IoT developer, author and speaker.
- Java EE - Official Java EE Twitter account.
- Java Magazine - Official Java Magazine account.
- Java.net - Official Java.net account.
- Java - Official Java Twitter account.
- Javin Paul - Well-known Java blogger.
- Lukas Eder - Founder and CEO Data Geekery (jOOQ).
- Mario Fusco - RedHatter, JUG coordinator, frequent speaker and author.
- Mark Reinhold - Chief Architect, Java Platform Group, Oracle.
- Markus Eisele - Java EE evangelist, Red Hat.
- Martijn Verburg - London JUG co-leader, speaker, author, Java Champion and much more.
- Martin Thompson - Pasty faced performance gangster.
- OpenJDK - Official OpenJDK account.
- Peter Lawrey - Peter Lawrey, Java performance expert.
- Reza Rahman - Java EE/GlassFish/WebLogic evangelist, author, speaker, open source hacker.
- Roberto Cortez - Java EE/JPA expert, speaker, open source.
- Simon Maple - Java Champion, virtualJUG founder, LJC leader, RebelLabs author.
- Stephen Colebourne - Java Champion, speaker.
- Tim Boudreau - Author and NetBeans guru.
- Trisha Gee - Java Champion and speaker.
Sites to read.
- Android Arsenal
- Google Java Style
- Java Code Geeks
- Java, SQL, and jOOQ
- The Java Specialist’ Newsletter
- The Takipi Blog
- Thoughts On Java
- Vanilla Java
- Vlad Mihalcea on Hibernate
Contributions are very welcome!
Please have a look at CONTRIBUTING for guidelines.