A curated list of awesome Java frameworks, libraries and software.
- Awesome Java
- Bean Mapping
- Bytecode Manipulation
- Cluster Management
- Code Analysis
- Code Coverage
- Code Generators
- Command-line Argument Parsers
- Constraint Satisfaction Problem Solver
- Continuous Integration
- Data structures
- Date and Time
- Dependency Injection
- Distributed Applications
- Distributed Databases
- Document Processing
- Formal Verification
- Functional Programming
- Game Development
- High Performance
- Hypermedia Types
- JSON Processing
- JVM and JDK
- Machine Learning
- Natural Language Processing
- Performance analysis
- Reactive libraries
- REST Frameworks
- Template Engine
- Web Crawling
- Web Frameworks
In existence since the beginning of time and which will continue being used long after the hype has waned.
- Apache Ant - Build process management with XML.
- Apache Hadoop - Storage and large-scale processing of data-sets on clusters of commodity hardware.
- Apache OpenNLP - Toolkit for common tasks like tokenization.
- Apache Velocity - Templates for HTML pages, emails or source code generation in general.
- FreeMarker - General templating engine without any heavyweight or opinionated dependencies.
- GlassFish - Application server and reference implementation for Java EE sponsored by Oracle.
- HornetQ - Clear, concise, modular and made to be embedded.
- Hudson - Continuous integration server still in active development.
- Java Modeling Language (JML) - Behavioral interface specification language that can be used to specify the behavior of code modules. It combines the design by contract approach of Eiffel and the model-based specification approach of the Larch family of interface specification languages, with some elements of the refinement calculus. Used by several other verification tools.
- JavaCC - More specific and slightly easier to learn. Has syntactic lookahead.
- JavaServer Faces - Oracle's open-source implementation of the JSF standard, Mojarra.
- JavaServer Pages - Common templating for websites with custom tag libraries.
- JUnit - Common testing framework.
- Launch4j - Wraps JARs in lightweight and native Windows executables.
- Quartz - Open-source job scheduler library with Apache 2.0 license.
- TestNG - Testing framework.
- Trove - Primitive collections.
Frameworks that ease bean mapping.
- Dozer - Mapper that copies data from one object to another, using annotations, API or XML configuration.
- JMapper - Using byte code manipulation for lightning fast mapping. Supporting annotations, API or XML configuration.
- MapStruct - Code generator which simplifies mappings between different bean types, based on a convention over configuration approach.
- ModelMapper - ModelMapper is an intelligent object mapping library that automatically maps objects to each other.
- Orika - Orika is a Java Bean mapping framework that recursively copies (among other capabilities) data from one object to another.
- Selma - Stupid Simple Statically Linked Mapper. Selma is an Annotation Processor Based bean mapper.
Tools which handle the build cycle 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.
- Byteman - Manipulate bytecode at runtime via DSL (rules) mainly for testing/troubleshooting.
- cglib - Bytecode generation library.
- Javassist - Tries to simplify the editing of bytecode.
Libraries which provide caching facilities.
- Caffeine - High performance, near optimal caching library.
- Ehcache - Distributed general purpose cache.
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.
- Apache Mesos - Abstracts CPU, memory, storage, and other compute resources away from machines.
- 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.
- Codacy - Continuous static analysis, code coverage, and software metrics to automate code reviews.
- Error Prone - Catches common programming mistakes as compile-time errors.
- FindBugs - Static analysis of bytecode to find potential bugs.
- Infer - Tool to produce a list of 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.
- Spoon - Library for analyzing and transforming Java source code.
Frameworks and tools that enable collection of code coverage metrics for test suites.
- Clover - Proprietary code coverage tool by Atlassian that relies on source-code instrumentation, instead of bytecode instrumentation.
- Cobertura - Relies on offline (or static) bytecode instrumentation and class loading to collect code coverage metrics; GPLv2 licensed.
- JaCoCo - Framework that enables collection of code coverage metrics, using both offline and runtime bytecode instrumentation; prominently used by EclEmma, the Eclipse code-coverage plugin.
Tools that generate patterns for repetitive code in order to reduce verbosity and error-proneness.
- ADT4J - JSR-269 code generator for algebraic data types.
- Auto - Generates factory, service, and value classes.
- FreeBuilder - Automatic generation of the Builder pattern.
- Immutables - Annotation processors to generate simple, safe and consistent value objects.
- JHipster - Yeoman source code generator for Spring Boot and AngularJS.
- Joda-Beans - Small framework that adds queryable properties to Java, enhancing JavaBeans.
- Lombok - Code generator which aims to reduce verbosity.
Command-line Argument Parsers
Libraries that make it easy to parse command line options, arguments, etc.
- Airline - Annotation-based framework for parsing Git like command line arguments.
- args4j - Small library to parse command like arguments similar to javac.
- JCommander - Command line arguments parsing framework with custom types and validation via implementing interfaces.
- JOpt Simple - Simple parser that uses the POSIX getopt() and GNU getopt_long() syntaxes. Does not use annotations, uses a fluent API instead.
Frameworks that help to create parsers, interpreters or compilers.
Libraries that provide external configuration.
- config - Configuration library for JVM languages.
- ini4j - Provides an API for handling Windows' INI files.
- owner - Reduces boilerplate of properties.
- KAConf - Annotation-based configuration system for Java and Kotlin.
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.
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.
- Concourse - Provides dockerized pipeline with configuration that can be saved in version control.
- 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.
- opencsv - Simple CSV parser.
- Super CSV - Powerful CSV parser with support for Dozer, Joda-Time and Java 8.
- 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 Hive - Data warehouse infrastructure built on top of Hadoop.
- Apache Phoenix - High performance relational database layer over HBase for low latency applications.
- Chronicle Map - Efficient in-memory (opt. persisted to disk) off-heap key-value store.
- eXist - A NoSQL document database and application platform.
- FlexyPool - Brings metrics and failover strategies to the most common connection pooling solutions.
- 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.
- Jedis - A small client for interaction with redis, with methods for commands.
- jetcd - A client library for etcd.
- jOOQ - Generates typesafe code based on SQL schema.
- Liquibase - Database-independent library for tracking, managing and applying database schema changes.
- MapDB - Embedded database engine that provides concurrent collections backed on disk or in off-heap memory.
- MariaDB4j - Launcher for MariaDB which requires no installation or external dependencies.
- Presto - Distributed SQL query engine for big data.
- Querydsl - Typesafe unified queries.
- Realm - Mobile database to run directly inside phones, tablets or wearables.
- Redisson - Allows for distributed and scalable data structures on top of a Redis server.
- Speedment - Database access library that utilizes the Java 8 Stream API for querying.
- sql2o - Thin JDBC wrapper that simplifies database access and provides simple mapping of ResultSets to POJOs.
- Vibur DBCP - JDBC connection pool library which offers advanced performance monitoring capabilities.
Efficient and specific data structures.
- Apache Avro - Data interchange format featuring among others: dynamic typing, untagged data, absence of manually assigned IDs.
- Apache Orc - Fast and efficient columnar storage format for hadoop based workloads.
- Apache Parquet - Columnar storage format based on assembly algorithms from the Dremel paper by Google.
- Apache Thrift - Data interchange format that originated at Facebook.
- Persistent Collection - Persistent and immutable analogue of the Java Collections Framework.
- 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.
- Almanac Converter - Simple conversion between different calendar systems.
- iCal4j - Parsing and building iCalendar RFC 5545 data models.
- Joda-Time - De facto standard date/time-library before Java 8.
- ThreeTenBP - Port of JSR 310 (java.time package) by the author of Joda-Time.
- 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.
- AspectJ - Seamless aspect-oriented programming extension.
- DCEVM - Modification of the JVM that allows unlimited redefinition of loaded classes at runtime.
- Faux Pas - Library that simplifies error handling by circumventing the issue that none of the functional interfaces in the Java Runtime is allowed by default to throw checked exceptions.
- HotswapAgent - Unlimited runtime class and resource redefinition.
- JavaParser - Parse, modify and generate Java code.
- JavaSymbolSolver - A symbol solver for Java.
- JRebel - Instantly reloads code and configuration changes without redeploys.
- Spring Loaded - Class reloading agent.
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.
- Atomix - Fault-tolerant distributed coordination framework.
- Axon Framework - Framework for creating CQRS applications.
- Copycat - Fault-tolerant state machine replication framework.
- Hazelcast - Highly scalable in-memory datagrid with a free open-source version.
- 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.
- OpenTSDB - Scalable and distributed time series database written on top of Apache HBase.
- OrientDB - Embeddable distributed database written on top of Hazelcast.
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.
- Boxfuse - Deployment of JVM application to AWS using the principles of Immutable Infrastructure.
- Capsule - Simple and powerful packaging and deployment. A fat JAR on steroids or a "Docker for Java" that supports JVM-optimized containers.
- 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.
- 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.
- really-executable-jars-maven-plugin - Maven plugin for making self-executing JARs.
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.
- docx4j - Creating and manipulating Microsoft Open XML files.
Formal-methods tools: proof assistants, model checking, symbolic execution etc.
- CATG - Concolic unit testing engine. Automatically generates unit tests using formal methods.
- Checker Framework - Pluggable type systems. Includes nullness types, physical units, immutability types and more.
- Daikon - Daikon detects likely program invariants and can generate JML specs based on those invariats.
- Java Path Finder (JPF) - JVM formal verification tool containing a model checker and more. Created by NASA.
- JMLOK 2.0 - Detects nonconformances between code and JML specification through the feedback-directed random tests generation, and suggests a likely cause for each nonconformance detected.
- KeY - The KeY System is a formal software development tool that aims to integrate design, implementation, formal specification, and formal verification of object-oriented software as seamlessly as possible. Uses JML for specification and symbolic execution for verification.
- OpenJML - Translates JML specifications into SMT-LIB format and passes the proof problems implied by the program to backend solvers.
Libraries that facilitate functional programming.
- cyclops-react - Monad and stream utilities, comprehensions, pattern matching, functional extensions for all JDK collections, future streams, trampolines and much more.
- derive4j - Java 8 annotation processor and framework for deriving algebraic data types constructors, pattern-matching, morphisms.
- 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.
- protonpack - Collection of stream utilities.
- StreamEx - Enhancing Java 8 Streams.
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 for working with geospatial data and algorithms.
- Apache SIS - Library for developing geospatial applications.
- Geo - GeoHash utilities in Java.
- Geotoolkit.org - Library for developing geospatial applications. Built on top of the Apache SIS project.
- GeoTools - Library that provides tools for geospatial data.
- GraphHopper - Road routing engine. Used as Java library or standalone web service.
- H2GIS - A spatial extension of the H2 database.
- Jgeohash - Library that can assist Java developers in using the GeoHash algorithm.
- Mapsforge - Software for the rendering of maps based on OpenStreetMap data.
- Spatial4j - General purpose spatial/geospatial ASL licensed open-source Java library.
Libraries to create modern graphical user interfaces.
- JavaFX - The successor of Swing.
- Scene Builder - Visual layout tool for JavaFX applications.
- SWT - The Standard Widget Toolkit (SWT) is a graphical widget toolkit for use with the Java platform.
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.
- Eclipse Collections - Collections framework inspired by Smalltalk.
- fastutil - Fast and compact type-specific collections.
- HPPC - Primitive collections.
- JCTools - Concurrency tools currently missing from the JDK.
- Koloboke - Hash sets and hash maps.
Libraries that handle serialization to hypermedia types.
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.
- Tess4J - A JNA wrapper for Tesseract OCR API.
- Thumbnailator - Thumbnailator is a high-quality thumbnail generation library for Java.
- TwelveMonkeys - Collection of plugins which extend the number of supported image file formats.
- ZXing - Multi-format 1D/2D barcode image processing library.
Libraries for serializing and deserializing JSON to and from Java objects.
- 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-datatype-money - Open-source Jackson module to support JSON serialization and deserialization of JavaMoney data types.
- Jackson - Similar to GSON but has performance gains if you need to instantiate the library more often.
- JSON-io - Convert Java to JSON. Convert JSON to Java. Pretty print JSON. Java JSON serializer.
- jsoniter - Fast and flexible library with iterator and lazy parsing API.
- LoganSquare - JSON parsing and serializing library based on Jackson's streaming API. Outperforms GSON & Jackson's library.
Libraries for processing data in JSON format.
- fastjson - Very fast processor with no additional dependencies and full data binding.
- Jolt - JSON to JSON transformation tool.
- JsonPath - Extract data from JSON using XPATH like syntax.
- JsonSurfer - Streaming JsonPath processor dedicated to processing big and complicated JSON data.
JVM and JDK
Current implementations of the JVM/JDK.
- Avian - JVM with both a JIT & AOT modes. Includes an iOS port.
- JDK 9 - Early access releases of JDK 9.
- OpenJDK - Open-source implementation for Linux.
- ParparVM - VM with non-blocking concurrent GC for iOS.
- Zulu OpenJDK 9 - Early access OpenJDK 9 builds for Windows, Linux, and Mac OS X.
- Zulu OpenJDK - OpenJDK builds for Windows, Linux, and Mac OS X through Java 8.
Libraries that log the behavior of an application.
- Apache Log4j 2 - Complete rewrite with a powerful plugin and configuration architecture.
- Graylog - Open-source aggregator suited for extended role and permission management.
- Kibana - Analyzes and visualizes log files. Some features require payment.
- Logback - Robust logging library with interesting configuration options via Groovy.
- Logbook - Extensible, open-source library for HTTP request and response logging.
- Logstash - Tool for managing log files.
- SLF4J - Abstraction layer which is to be used with an implementation.
- tinylog - Lightweight logging framework with static logger class.
- Tracer - Call tracing and log correlation in distributed systems.
Tools that provide specific statistical algorithms which allow learning from data.
- Apache Flink - Fast and reliable large-scale data processing engine.
- Apache Mahout - Scalable algorithms focused on collaborative filtering, clustering and classification.
- Apache Spark - Data analytics cluster computing framework.
- DatumBox - Provides several algorithms and pre-trained models for natural language processing.
- 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.
- JSAT - Algorithms for pre-processing, classification, regression, and clustering with support for multi-threaded execution.
- Oryx 2 - A framework for building real-time large scale machine learning applications, which also includes end-to-end applications for collaborative filtering, classification, regression, and clustering.
- Smile - The Statistical Machine Intelligence and Learning Engine provides a set of machine learning algorithms and a visualization library.
- 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.
- JeroMQ - Implementation of ZeroMQ.
- Nakadi - Provides a RESTful API on top of Kafka.
- RocketMQ - A fast, reliable, and scalable distributed messaging platform.
- Smack - Cross-platform XMPP client library.
- Codename One - Cross platform solution for writing native mobile (iOS, Android, etc.)
- CQEngine - Ultra-fast SQL-like queries on Java collections.
- Design Patterns - Implementation and explanation of the most common design patterns.
- Failsafe - Simple failure handling with retries and circuit breakers.
- J2ObjC - Java to Objective-C translator for porting Android libraries to iOS.
- jabba - Java Version Manager inspired by nvm.
- javaslang-circuitbreaker - Functional fault tolerance library.
- JavaX - Reinventing and extending Java with a focus on simplicity.
- JBake - Static website generator.
- Jimfs - In-memory file system.
- Joda-Money - Basic currency and money classes and algorithms not provided by the JDK.
- JPad - Snippet runner.
- Lanterna - Easy console text GUI library similar to curses.
- LightAdmin - Pluggable CRUD UI library for rapid application development.
- Membrane Service Proxy - An open source, reverse proxy framework written in Java.
- Modern Java - A Guide to Java 8 - Popular Java 8 guide.
- Modernizer - Detect uses of legacy Java APIs.
- OpenRefine - Tool for working with messy data: cleaning, transforming, extending it with web services and linking it to databases.
- TypeTools - Tools for resolving generic types.
Tools for managing microservices, i.e. creation, coordination or discovery.
- Apollo - Libraries for writing composable microservices.
- consul-api - Client for the Consul API a distributed, highly available and datacenter-aware registry/discovery service.
- Eureka - REST based service registry for resilient load balancing and failover.
- Lagom - Framework for creating microservice-based systems.
- SnopEE - Discovery service for Java EE microservices.
- restQL-core - Microservice query language that fetches information from multiple services.
Tools that monitor applications in production.
- AppDynamics - Performance monitor.
- Glowroot - Open source Java APM.
- JavaMelody - Performance monitoring and profiling.
- jmxtrans - Tool to connect to multiple JVMs and to query them for their attributes via JMX. Its query language is based on JSON, which allows non-Java programmers to access the JVMs attributes. Likewise, this tool supports different output writes, including Graphite, Ganglia, StatsD, among others.
- Jolokia - JMX over REST.
- Kamon - Tool for monitoring applications running on the JVM.
- Metrics - Expose metrics via JMX or HTTP and can send them to a database.
- New Relic - Performance monitor.
- nudge4j - Remote developer console from the browser for Java 8 via bytecode injection.
- OverOps - In-Production error monitoring and debugging.
- Pinpoint - Open source APM tool.
- Prometheus - Provides a multi-dimensional data model, DSL, autonomous server nodes and much more.
- SPM - Performance monitor with distributing transaction tracing for JVM apps.
- Stagemonitor - Open source performance monitoring and transaction tracing for JVM apps.
For working with platform-specific native libraries.
- JNA - Work with native libraries without writing JNI. Also provides interfaces to common system libraries.
- JNR - Work with native libraries without writing JNI. Also provides interfaces to common system libraries. Same goals as JNA, but faster, and serves as the basis for the upcoming Project Panama.
- JavaCPP - Provides efficient and easy access to native C++.
Natural Language Processing
Libraries that specialize on processing text.
- CoreNLP - Stanford's CoreNLP provides a set of fundamental tools for tasks like tagging, named entity recognition, sentiment analysis and many more.
- DKPro - A collection of re-usable NLP tools for linguistic pre-processing, machine learning, lexical resources, etc.
- LingPipe - Toolkit for a variety of tasks ranging from POS tagging to sentiment analysis.
Libraries for network programming.
- Async Http Client - Asynchronous HTTP and WebSocket client library.
- Comsat - Integrates standard Java web-related APIs with Quasar fibers and actors.
- Finagle - Extensible RPC system used to construct high-concurrency servers. It implements uniform client and server APIs for several protocols, and is protocol agnostic, which simplifies the implementation of new protocols.
- Grizzly - NIO framework. Used as a network layer in Glassfish.
- gRPC - RPC framework based on protobuf and HTTP/2.
- MINA - Abstract event-driven async I/O API for network operations over TCP/IP and UDP/IP via Java NIO.
- Netty - Framework for building high performance network applications.
- Nifty - Implementation of Thrift clients and servers on Netty.
- OkHttp - HTTP+SPDY client.
- Riptide - Client-side response routing for Spring's RestTemplate.
- Undertow - Web server providing both blocking and non-blocking API’s based on NIO. Used as a network layer in WildFly.
- urnlib - Java library for representing, parsing and encoding URNs as in RFC 2141.
APIs which handle the persistence of objects.
- Apache Cayenne - Provides clean, static API for data access. Also includes GUI Modeler for working with database mappings, DB reverse engineering and generation.
- 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.
Java platform as a service.
- AWS Elastic Beanstalk - AWS-based with support for Tomcat and Jetty.
- AWS Lambda - Serverless computation.
- Google App Engine - PaaS on Google's infrastructure.
- Heroku - Abstract computing environments.
- Jelastic - Supports Tomcat, Jetty, GlassFish, JBoss, TomEE and WildFly.
- OpenShift Enterprise - On premise solution.
Everything that helps with the creation of PDF files.
- Apache FOP - Creates PDF from XSL-FO.
- Apache PDFBox - Toolbox for creating and manipulating PDF.
- Dynamic Jasper - Abstraction layer to JasperReports.
- 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.
- fastThread - Analyze and visualize thread dumps with a free cloud-based upload interface.
- GCeasy - Tool to analyze and visualize GC logs. It provides a free cloud-based upload interface.
- honest-profiler - An low-overhead, bias-free sampling profiler.
- jHiccup - Logs and records platform JVM stalls.
- JITWatch - Analyze the JIT compiler optimisations made by the HotSpot JVM.
- JMH - JMH is a Java harness for building, running, and analysing nano/micro/milli/macro benchmarks written in Java and other languages targeting the JVM.
- JProfiler - Profiler.
- LatencyUtils - Utilities for latency measurement and reporting.
- XRebel - Profiler for web applications.
- YourKit Java Profiler - Profiler.
Frameworks that are suites of multiple libraries encompassing several categories.
- CUBA Platform - High level framework for development of enterprise applications with rich web interface, based on Spring, EclipseLink and Vaadin.
- Spring - Provides many packages ranging from dependency injection to aspect-oriented programming to security.
- Light-Java - A fast, lightweight and productive microservices framework with security built in.
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.
- vert.x - Polyglot event-driven application framework.
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.
- Microserver — A convenient extensible Microservices plugin system for Spring & Spring Boot, with over 30 plugins and growing, that supports both micro-monolith and pure microservices styles.
- RAML - Modeling language to generate REST APIs with contract first.
- Rapidoid - A simple, secure and extremely fast framework consisting of embedded HTTP server, GUI components and dependency injection.
- rest.li - Framework for building robust, scalable RESTful architectures using type-safe bindings and asynchronous, non-blocking IO with an end-to-end developer workflow that promotes clean practices, uniform interface design and consistent data modeling.
- 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.
- Restlet Framework - Pioneering framework with powerful routing and filtering capabilities, unified client and server API.
- 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, analysis and visualization.
- DataMelt - Environment for scientific computation, data analysis and data visualization.
- GraphStream - Library for modeling and analysis of dynamic graphs.
- JGraphT - Graph library that provides mathematical graph-theory objects and algorithms.
- JGraphX - Library for visualisation (mainly Swing) and interaction with node-edge graphs.
- Erdos - Modular, light and easy graph theoretic framework.
Engines which index documents for search and analysis.
- Apache Lucene - High-performance, full-featured cross-platform text search engine library.
- 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.
- Hdiv - Runtime application self-protection against OWASP Top 10 security risks such us Insecure Direct Object References, SQL injection, Cross-Site Scripting (XSS), Cross-Site Request Forgery (CSRF) and much more.
- jjwt - Java JWT: JSON Web Token for Java and Android.
- Keycloak - Integrated SSO and IDM for browser apps and RESTful web services.
- Keyczar - Easy to use, yet safe encryption framework with key versioning.
- Nbvcxz - Advanced password strength estimation.
- OACC - Provides permission-based authorization services.
- pac4j - Security engine.
- 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.
- FST - JDK compatible high performance object graph serialization.
- Kryo - Fast and efficient object graph serialization framework.
- 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.
- nanohttpd - Tiny, easily embeddable HTTP server.
- 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.
- Handlebars.java - Logic-less and semantic Mustache templates.
- Jtwig - Modular, configurable and fully tested template engine.
- 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.
- Citrus - Integration testing framework with focus on client- and serverside messaging.
- ConcurrentUnit - Toolkit for testing multi-threaded and asynchronous applications.
- Cucumber - BDD testing framework.
- Cukes-REST - A collection of Gherkin steps for REST-service testing using Cucumber.
- Gatling - Load testing tool designed for ease of use, maintainability and high performance.
- GreenMail - In-memory email server for integration testing. Supports SMTP, POP3 and IMAP including SSL.
- Hamcrest - Matchers that can be combined to create flexible expressions of intent.
- J8Spec - J8Spec is a library that allows tests written in Java to follow the BDD style introduced by RSpec and Jasmine.
- JSONAssert - Simplifies testing of JSON strings.
- JBehave - Framework for Behavioural Driven Development.
- JGiven - Developer-friendly BDD testing framework compatible with JUnit and TestNG.
- JMockit - Mocks static, final methods and more.
- junit-dataprovider - A TestNG like dataprovider runner for JUnit.
- JUnitParams - Creation of readable and maintainable parametrised tests.
- Lamdba Behave - Descriptive behavioural specification framework.
- Mockito - Creation of test double objects in automated unit tests for the purpose of TDD or BDD.
- MockServer - Allows mocking of systems that are integrated with HTTP/S.
- Moco - Concise web services for stubs and mocks, Duke's Choice Award 2013.
- PIT - Fast mutation-testing framework for evaluating fault-detection abilities of existing JUnit or TestNG test-suites.
- pojo-tester - Automatically performs tests on basic POJO-methods.
- PowerMock - Enables mocking of static methods, constructors, final classes and methods, private methods and removal of static initializers.
- raml-tester - Tests if a request/response matches a given RAML definition.
- 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.
- TestContainers - Provides throwaway instances of common databases, Selenium web browsers, or anything else that can run in a Docker container.
- Truth - Google's assertion and proposition framework.
- WireMock - Stubs 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.
- CRaSH - Provides a shell into a JVM that's running CRaSH. Used by Spring Boot and others.
- Dex - Java/JavaFX tool capable of powerful ETL and data visualization.
- Embulk - Bulk data loader that helps data transfer between various databases, storages, file formats, and cloud services.
- 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.
- JavaVerbalExpressions - A library that helps to construct difficult regular expressions.
- minio-java - Provides simple APIs to access any Amazon S3 compatible object storage server.
- Protégé - Provides an ontology editor and a framework to build knowledge-based systems.
- Underscore-java - Port of Underscore.js functions.
- JGit - A lightweight pure Java library implementing the Git version control system.
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.
- Baratine - Toolkit for building distributed and reactive applications for multiple environments, either standalone or embedded.
- Blade - Lightweight, modular framework which aims to be elegant and simple.
- Bootique - Minimally opinionated framework for runnable apps.
- Grails - Groovy framework with the aim to provide a highly productive environment by favoring convention over configuration, no XML and support for mixins.
- Jooby - Scalable, fast and modular micro framework which offers multiple programming models.
- 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.
- 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.
Websites that provide a frontend for this list. Please note, there won't be an official website. We don't associate with a particular website and everybody is allowed to create one.
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, JUG Leader, Devoxx4Kids-er, VP of Developer Advocacy at Couchbase.
- 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 - Official Java Twitter account.
- Javin Paul - Well-known Java blogger.
- Lukas Eder - Java Champion, speaker, JUG.ch co-leader, 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.
- Simon Maple - Java Champion, virtualJUG founder, LJC leader, RebelLabs author.
- Stephen Colebourne - Java Champion, speaker.
- Trisha Gee - Java Champion and speaker.
Sites to read.
- Google Java Style
- Java Algorithms and Clients
- Java, SQL, and jOOQ
- The Takipi Blog
- Vanilla Java
Contributions are very welcome!
Please have a look at CONTRIBUTING for guidelines.