A curated list of awesome Java frameworks, libraries and software.
- Awesome Java
- Beginner Books
- Top Java Books
- 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.
Intro to Java Programming, Comprehensive Version (10th Edition) http://amzn.to/2jcPumF
This is the perfect Java Programming book, Dr. Liang teaches concepts of problem-solving and object-oriented programming using a fundamentals-first approach.
Java How To Program (Early Objects) (10th Edition) http://amzn.to/2jcHbXW
one of the best Java programming books for beginners. If you are completely new to Java this book goes to great lengths to provide you in-depth explanations about every little thing.
Head First Java, 2nd Edition http://amzn.to/2jPTEmw
delivers a highly interactive, multisensory learning experience that lets new programmers pick up the fundamentals of the Java language quickly.
Beginning Programming with Java For Dummies, 4th Edition http://amzn.to/2kh0pxi
Covering everything from basic Java development concepts to the latest tools and techniques used in Java, it’s a comprehensive guide to learning one of the most popular programming languages worldwide.
Java: A Beginner's Guide, Sixth Edition http://amzn.to/2jcYbx6
Essential Java Programming Skills--Made Easy! A very helpful Java book covering all the basics (and much more) of the Java programming language. Very well written
Java: The Complete Reference, Ninth Edition http://amzn.to/2jcYg3S
Fully updated for Java SE 8, Java: The Complete Reference, Ninth Edition explains how to develop, compile, debug, and run Java programs.
Effective Java (2nd Edition) http://amzn.to/2k1yynA
Are you looking for a deeper understanding of the Java programming language so that you can write code that is clearer, more correct, more robust, and more reusable
Beginning Java Programming: The Object-Oriented Approach http://amzn.to/2k1yG6y
A comprehensive Java guide, with samples, exercises, case studies, and step-by-step instruction
Top Java Books
Head First Java http://amzn.to/2j5MvkB
Head First Java is the best Java book for any programmer who are new in both programming and Java.
Head First Design Patterns http://amzn.to/2j5OyFD
Head First Design Pattern is another top class Java book from Head First lab, I guess, this is so far their best title.
Effective Java http://amzn.to/2jfY2sN
Effective Java is one of the best or top Java books in my record and most enjoyable as well.
Java Concurrency in Practice http://amzn.to/2j5TdHz
Java Concurrency in Practice is another classic from Joshua Bloch, Doug Lea, and team.
Java Generics and Collections http://amzn.to/2jfTKBI
Java Generics and Collection by Naftalin and Philip Wadler from O'Reilly is another good book on Java
Java Performance from Binu John http://amzn.to/2ktP502
Another good book in Java to learn about JVM internals, Garbage collection, JVM tuning, profiling etc and I highly recommend every senior Java developer to read this book.
Java Puzzlers http://amzn.to/2jqx1X7
Java Puzzlers is another worth reading Java book from Joshua Bloch, this time with Neal Gafter.
Head First Object Oriented Analysis and Design http://amzn.to/2jfWFux Another good book on Java programming and design principles from Head First series.
Thinking in Java http://amzn.to/2jqAbKn Thinking in Java book is written by Bruce Eckel who is also the author of Thinking in C++ and he uses his unique style to teach Java concept.
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 ![c] - 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.
- 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.
- JRebel ![c] - 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 ![c] - 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 ![c] - 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 ![c] - 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 ![c] - 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.
Tools that monitor applications in production.
- AppDynamics ![c] - 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 ![c] - Performance monitor.
- nudge4j - Remote developer console from the browser for Java 8 via bytecode injection.
- OverOps ![c] - 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 ![c] - 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.
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 ![c] - AWS-based with support for Tomcat and Jetty.
- AWS Lambda ![c] - Serverless computation.
- Google App Engine ![c] - PaaS on Google's infrastructure.
- Heroku ![c] - Abstract computing environments.
- Jelastic ![c] - Supports Tomcat, Jetty, GlassFish, JBoss, TomEE and WildFly.
- OpenShift Enterprise ![c] - 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 ![c] - Analyze and visualize thread dumps with a free cloud-based upload interface.
- GCeasy ![c] - 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 ![c] - Profiler.
- LatencyUtils - Utilities for latency measurement and reporting.
- XRebel ![c] - Profiler for web applications.
- YourKit Java Profiler ![c] - 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.
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.
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.
- 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.
- 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.
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.
Effective Java (2nd Edition) http://amzn.to/2k1yynA
Java 8 in Action http://amzn.to/2jg9ip8
Java Concurrency in Practice http://amzn.to/2j5Y0IW
Thinking in Java http://amzn.to/2jg7QTS
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](https://twitt