This is a list of repositories sorted by GitHub stars.
Table of Contents
Bean Mapping, Build, Bytecode Manipulation, Caching, CLI, Cluster Management, Code Analysis, Code Coverage, Code Generators, Compiler-compiler, Computer Vision, Configuration, Constraint Satisfaction Problem Solver, CSV, Data Structures, Database, Date and Time, Dependency Injection, Development, Distributed Applications, Distributed Transactions, Distribution, Document Processing, Financial, Formal Verification, Functional Programming, Game Development, Geospatial, GUI, High Performance, HTTP Clients, Hypermedia Types, IDE, Imagery, Introspection, Job Scheduling, JSON, JVM and JDK, Logging, Machine Learning, Messaging, Microservice, Miscellaneous, Mobile Development, Monitoring, Native, Natural Language Processing, Networking, ORM, PaaS, PDF, Performance analysis, Apache Commons, Other, Processes, Reactive libraries, REST Frameworks, Science, Search, Security, Serialization, Server, Template Engine, Testing, BDD, Fixtures, Frameworks, Matchers, Miscellaneous, Mocking, Utility, Version Managers, Web Crawling, Web Frameworks,Bean Mapping
Frameworks that ease bean mapping.
6624 Stars
Code generator that simplifies mappings between different bean types, based on a convention-over-configuration approach.
2197 Stars
Intelligent object mapping library that automatically maps objects to each other.
1278 Stars
JavaBean-mapping framework that recursively copies (among other capabilities) data from one object to another.
219 Stars
Uses byte code manipulation for lightning-fast mapping. Supports annotations and API or XML configuration.
211 Stars
Annotation processor-based bean mapper.
115 Stars
Lambda and method handle-based mapping which requires code and not annotations if objects have different names.
82 Stars
Provides fluent API for typesafe domain model validation and mapping. It uses annotations, code generation and a type safe DSL to make bean validation and mapping fast and easy.
Build
Tools that handle the build cycle and dependencies of an application.
21862 Stars
Tool from Google that builds code quickly and reliably.
15672 Stars
Incremental builds programmed via Groovy instead of declaring XML. Works well with Maven's dependency management.
8568 Stars
Encourages the creation of small, reusable modules consisting of code and resources.
4003 Stars
Declarative build and dependency management that favors convention over configuration. It might be preferable to Apache Ant, which uses a rather procedural approach and can be difficult to maintain.
Bytecode Manipulation
Libraries to manipulate bytecode programmatically.
14141 Stars
Java 8 Jar & Android APK reverse engineering suite. (GPL-3.0-only)
5877 Stars
Further simplifies bytecode generation with a fluent API.
5393 Stars
JVM reverse engineering toolkit, essentially an IDE for Java bytecode.
4702 Stars
Bytecode generation library.
3969 Stars
Tries to simplify bytecode editing.
1271 Stars
Manipulate bytecode at runtime using real Java code.
467 Stars
Manipulate bytecode at runtime via DSL (rules); mainly for testing/troubleshooting. (LGPL-2.1-or-later)
66 Stars
Dynamically injects failure/latency at the bytecode level according to principles of chaos engineering.
41 Stars
Provides low level bytecode generation.
Caching
Libraries that provide caching facilities.
14720 Stars
High-performance, near-optimal caching library.
1929 Stars
Distributed general-purpose cache.
1096 Stars
Highly concurrent key/value datastore used for caching.
701 Stars
In-memory high performance caching library.
CLI
Libraries for everything related to the CLI.
4557 Stars
ANSI colors and styles in usage help with annotation-based POSIX/GNU/any syntax, subcommands, strong typing for both options and positional args.
2139 Stars
Easy console text-GUI library, similar to curses. (LGPL-3.0-only)
1902 Stars
Command-line argument-parsing framework with custom types and validation via implementing interfaces.
1328 Stars
Includes features from modern shells like completion or history.
1056 Stars
ANSI escape codes to format console output.
849 Stars
Annotation-based framework for parsing Git-like command-line arguments.
765 Stars
Small library to parse command-line arguments.
466 Stars
Library to draw tables in ASCII.
338 Stars
Fluent parser that uses the POSIX#getopt and GNU#getopt_long syntaxes.
316 Stars
Aids the creation of full console-based applications.
151 Stars
Graphical primitives for the console.
78 Stars
Reflectionless command line parser.
Cluster Management
Frameworks that can dynamically manage applications inside of a cluster.
819 Stars
Mesos framework that makes deployment and operations easy. It supports web services, background workers, scheduled jobs, and one-off tasks.
631 Stars
Mesos framework for long-running services and cron jobs.
Code Analysis
Tools that provide metrics and quality measurements.
29903 Stars
Provides Alibaba's coding guidelines for PMD, IDEA and Eclipse.
14547 Stars
Modern static analysis tool for verifying the correctness of code.
7991 Stars
Static analysis of coding conventions and standards. (LGPL-2.1-or-later)
6642 Stars
Catches common programming mistakes as compile-time errors.
4526 Stars
Source code analysis for finding bad coding practices.
3455 Stars
Eliminates NullPointerExceptions with low build-time overhead.
3259 Stars
Static analysis of bytecode to find potential bugs. (LGPL-2.1-only)
1603 Stars
Library for analyzing and transforming Java source code.
1070 Stars
Static analyzer for SonarQube & SonarLint. (LGPL-3.0-only)
322 Stars
Identifies and prioritizes God Classes and Highly Coupled classes.
184 Stars
Static code analysis with Neo4J-based query language. (GPL-3.0-only)
154 Stars
Error Prone extensions: extra bug checkers and a large battery of Refaster templates.
Code Coverage
Frameworks and tools that enable code coverage metrics collection for test suites.
3912 Stars
Framework that enables collection of code coverage metrics, using both offline and runtime bytecode instrumentation.
1006 Stars
Relies on offline (or static) bytecode instrumentation and class loading to collect code coverage metrics. (GPL-2.0-only)
55 Stars
Relies on source-code instrumentation instead of bytecode instrumentation.
Code Generators
Tools that generate patterns for repetitive code in order to reduce verbosity and error-proneness.
21077 Stars
Yeoman source code generator for Spring Boot and AngularJS.
12430 Stars
Code generator that aims to reduce verbosity.
10567 Stars
API to generate source files.
10298 Stars
Generates factory, service, and value classes.
3350 Stars
Annotation processors to generate simple, safe and consistent value objects.
814 Stars
Automatically generates the Builder pattern.
573 Stars
Companion builder class, withers and templates for Java records.
148 Stars
Simple and light code generator available as an Eclipse Plugin and also as a CLI.
139 Stars
JSR-269 code generator for algebraic data types.
138 Stars
Small framework that adds queryable properties to Java, enhancing JavaBeans.
125 Stars
Discovers files that need generated code, updates automatically and writes to the source with a convenient API.
56 Stars
Generates Lightweight JAX-RS style http servers using Javalin or Helidon (Nima) SE.
0 Stars
Plugin for IntelliJ IDEA. Provides visual tools for generating JPA entities, Spring Data JPA repositories, Liquibase changelogs and SQL scripts. Offers automatic Liquibase/Flyway script generation by comparing model to DB, and reverse engineering JPA entities from DB tables.
Compiler-compiler
Frameworks that help to create parsers, interpreters or compilers.
Computer Vision
Libraries which seek to gain high level information from images and videos.
Configuration
Libraries that provide external configuration.
6047 Stars
Configuration library supporting Java properties, JSON or its human optimized superset HOCON.
3041 Stars
High-level API for Apache ZooKeeper.
901 Stars
Reduces boilerplate of properties.
563 Stars
Highly-available version-controlled service configuration repository based on Git, ZooKeeper and HTTP/2.
554 Stars
Modern configuration library for distributed apps written in Java.
323 Stars
Configuration library with support for various configuration formats and transformations.
290 Stars
Configuration system designed for microservices which helps to separate configuration from code. The configuration for different services can have common and specific parts and can be dynamically distributed.
59 Stars
Annotation-based configuration system for Java and Kotlin.
44 Stars
Twelve-factor configuration library which uses environment-specific files.
34 Stars
Loads yaml and properties files, supports dynamic configuration, plugins, file-watching and config event listeners.
24 Stars
Lightweight yet powerful configuration library which supports resolution of properties from external sources and an extensible post-processing/conversion mechanism.
Constraint Satisfaction Problem Solver
Libraries that help with implementing optimization and satisfiability problems.
654 Stars
Off-the-shelf constraint satisfaction problem solver that uses constraint programming techniques.
520 Stars
Flexible solver with Spring/Quarkus support and quickstarts for the Vehicle Routing Problem, Maintenance Scheduling, Employee Shift Scheduling and much more.
213 Stars
Includes an interface for the FlatZinc language, enabling it to execute MiniZinc models. (AGPL-3.0)
68 Stars
Business planning and resource scheduling optimization solver.
CSV
Frameworks and libraries that simplify reading/writing CSV data.
893 Stars
One of the fastest and most feature-complete parsers. Also comes with parsers for TSV and fixed-width records.
514 Stars
Powerful CSV parser with support for Dozer, Joda-Time and Java 8.
484 Stars
Performance-optimized, dependency-free and RFC 4180 compliant.
194 Stars
Jackson extension for reading and writing CSV.
Data Structures
Efficient and specific data structures.
62527 Stars
Google's data interchange format.
10037 Stars
Data interchange format that originated at Facebook.
4134 Stars
Clean, lightweight protocol buffers.
3299 Stars
Fast and efficient compressed bitmap.
2963 Stars
Simple Binary Encoding, one of the fastest message formats around.
2677 Stars
Data interchange format with dynamic typing, untagged data, and absence of manually assigned IDs.
2461 Stars
Lightning-fast, transactional, file-based FIFO.
2273 Stars
Columnar storage format based on assembly algorithms from Google's paper on Dremel.
738 Stars
Persistent and immutable analogue of the Java Collections Framework.
641 Stars
Fast and efficient columnar storage format for Hadoop-based workloads.
543 Stars
Fast and persistent queue based on memory-mapped files.
51 Stars
Probabilistic data structure for computing union, intersection, and set cardinality in loglog space.
Database
Everything that simplifies interactions with the database.
22242 Stars
Allows for distributed and scalable data structures on top of a Redis server.
19070 Stars
High-performance JDBC connection pool.
13128 Stars
High-performance SQL database for time series. Supports InfluxDB line protocol, PostgreSQL wire protocol, and REST.
13047 Stars
High-performance, column-oriented, distributed data store.
11455 Stars
Small client for interaction with Redis, with methods for commands.
11413 Stars
Mobile database to run directly inside phones, tablets or wearables.
9469 Stars
Low latency data streaming platform for change data capture.
9043 Stars
Distributed SQL query engine for big data.
7605 Stars
Simple database migration tool.
6199 Stars
Distributed ID generate service.
5788 Stars
Generates typesafe code based on SQL schema.
5174 Stars
Lettuce is a scalable Redis client for building non-blocking Reactive applications.
4796 Stars
Embedded database engine that provides concurrent collections backed on disk or in off-heap memory.
4477 Stars
Typesafe unified queries.
4222 Stars
Database-independent library for tracking, managing and applying database schema changes.
4177 Stars
Dynamic data management framework. It contains many of the pieces that comprise a typical database management system.
3965 Stars
Small SQL database notable for its in-memory functionality.
3131 Stars
Modern, lightweight but powerful object mapping and SQL generator. Easily map to or create databases, or perform queries and updates from any Java-using platform.
2650 Stars
Efficient, in-memory (opt. persisted to disk), off-heap key-value store.
2116 Stars
Client for the Elasticsearch REST API.
2076 Stars
Database access library that utilizes Java 8's Stream API for querying.
1866 Stars
Convenient abstraction of JDBC.
1853 Stars
Distributed, schema on-the-fly, ANSI SQL query engine for Big Data exploration.
1143 Stars
Highly concurrent transactional schema-less and ACID-compliant embedded database.
1015 Stars
Brings metrics and failover strategies to the most common connection pooling solutions.
1006 Stars
High-performance relational database layer over HBase for low-latency applications.
656 Stars
Typesafe database queries via symbolic execution of Java 8 Lambdas (on top of JPA or jOOQ).
400 Stars
NoSQL document database and application platform. (LGPL-2.1-only)
387 Stars
Universal, flexible, high-performance distributed ID generator.
325 Stars
LDAPv3 compliant directory service, developed for the Java platform, providing a high performance, highly available, and secure store for the identities.
196 Stars
ArangoDB Java driver.
137 Stars
Client library for etcd.
96 Stars
JDBC connection pool library with advanced performance monitoring capabilities.
89 Stars
Spring Data JPA MongoDB Expressions
Allows you to use MongoDB query language to query your relational database.
15 Stars
Build JPA Criteria queries using a Stream-like API.
12 Stars
Lightweight ORM with database reverse engineering features.
2 Stars
Launcher for MariaDB that requires no installation or external dependencies.
Date and Time
Libraries related to handling date and time.
693 Stars
Parse and build iCalendar [RFC 5545](https://tools.ietf.org/html/rfc5545) data models.
407 Stars
Advanced date and time library. (LGPL-2.1-only)
382 Stars
Additional date-time classes that complement those in JDK 8.
185 Stars
Determines the holidays for a given year, country/name and eventually state/region.
Dependency Injection
Libraries that help to realize the [Inversion of Control](https://en.wikipedia.org/wiki/Inversion_of_control) paradigm.
17241 Stars
Compile-time injection framework without reflection.
12260 Stars
Lightweight and opinionated framework that completes Dagger.
820 Stars
Extensions and utilities that enhance Google Guice.
352 Stars
Ultra-lightweight, JSR-330-compliant dependency injection library.
180 Stars
Microservice-focused compile-time injection framework without reflection.
146 Stars
CDI extension framework.
110 Stars
Lightweight and dynamic dependency injection framework.
54 Stars
Lightweight dependency injection framework. (LGPL-3.0-only)
Development
Augmentation of the development process at a fundamental level.
5046 Stars
Parse, modify and generate Java code.
2159 Stars
Unlimited runtime class and resource redefinition. (GPL-2.0-only)
2070 Stars
Re-energizes Java with powerful features like type-safe metaprogramming, structural typing and extension methods.
1733 Stars
JVM modification that allows unlimited redefinition of loaded classes at runtime. (GPL-2.0-only)
292 Stars
Symbol solver.
243 Stars
Seamless aspect-oriented programming extension.
128 Stars
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.
90 Stars
Allows checked exceptions in functional interfaces and converts exceptions to Optional return.
74 Stars
Ignores checked exceptions without bytecode manipulation. Can also be used inside Java 8 stream operations.
21 Stars
Enable infinite recursion using tail call optimization.
Distributed Applications
Libraries and frameworks for writing distributed and fault-tolerant applications.
13045 Stars
Gateway service that provides dynamic routing, monitoring, resiliency, security, and more.
11735 Stars
Coordination service with distributed configuration, synchronization, and naming registry for large distributed systems.
9231 Stars
Functional fault tolerance library.
6518 Stars
Realtime computation system.
5699 Stars
Highly scalable in-memory datagrid with a free open-source version.
4535 Stars
Lightweight threads and actors for the JVM.
4039 Stars
Simple failure handling with retries and circuit breakers.
2344 Stars
Fault-tolerant distributed coordination framework.
2257 Stars
In-memory data management system that provides reliable asynchronous event notifications and guaranteed message delivery.
989 Stars
Toolkit for reliable messaging and cluster creation.
596 Stars
Embeddable Cluster-Membership library based on SWIM and gossip protocol.
53 Stars
High-performance reverse proxy server with specialized session management and credential replay functionality.
42 Stars
Circuit breaker design pattern for Dropwizard. (GPL-2.0-only)
Distributed Transactions
Distributed transactions provide a mechanism for ensuring consistency of data updates in the presence of concurrent access and partial failures.
438 Stars
Provides transactions for REST, SOA and microservices with support for JTA and XA.
222 Stars
Provides support for traditional ACID and compensation transactions, also complies with JTA, JTS and other standards. (LGPL-2.1-only)
0 Stars
Simple but complete implementation of the JTA 1.1 API.
0 Stars
Delivers high performance and easy to use distributed transaction services under a microservices architecture.
Distribution
Tools that handle the distribution of applications in native formats.
2510 Stars
Packs JARs, assets and the JVM for native distribution on Windows, Linux and macOS.
1151 Stars
Simple and powerful packaging and deployment. A fat JAR on steroids, or a "Docker for Java" that supports JVM-optimized containers.
889 Stars
Maven and Gradle plugin which provides an easy way to package Java applications in native Windows, Mac OS X or GNU/Linux executables, and generate installers for them.
492 Stars
A system for deploying Java applications to end-user computers and keeping them up to date. Developed as an alternative to Java Web Start.
480 Stars
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.
425 Stars
Binary artifact management toolkit which hosts them on the file system or S3.
329 Stars
Deploy desktop apps as native Mac, Windows or Linux bundles.
317 Stars
Setup authoring tool for cross-platform deployments.
124 Stars
really-executable-jars-maven-plugin
Maven plugin for making self-executing JARs.
46 Stars
Builds optimized runtimes over HTTP.
Document Processing
Libraries that assist with processing office document formats.
1980 Stars
Create and manipulate Microsoft Open XML files.
1783 Stars
Supports OOXML (XLSX, DOCX, PPTX) as well as OLE2 (XLS, DOC or PPT).
568 Stars
High performance library to read and write large Excel (XLSX) worksheets.
510 Stars
API for document format conversion using third-party converters such as MS Word.
78 Stars
Annotation-based API for reading data from Excel sheets into POJOs with focus on reduced overhead.
Financial
Libraries related to the financial domain.
1891 Stars
Library for technical analysis.
720 Stars
Integration with the Stripe API.
525 Stars
Trading bot framework.
502 Stars
Platform for trading venues.
303 Stars
Low-latency financial information exchange.
40 Stars
Integration with the Square API.
Formal Verification
Formal-methods tools: proof assistants, model checking, symbolic execution, etc.
956 Stars
Pluggable type systems. Includes nullness types, physical units, immutability types and more. (GPL-2.0-only WITH Classpath-exception-2.0)
482 Stars
JVM formal verification tool containing a model checker and more. Created by NASA.
190 Stars
Detects likely program invariants and generates JML specs based on those invariants.
128 Stars
Translates JML specifications into SMT-LIB format and passes the proof problems implied by the program to backend solvers. (GPL-2.0-only)
97 Stars
Concolic unit testing engine. Automatically generates unit tests using formal methods.
33 Stars
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. (GPL-2.0-or-later)
4 Stars
Detects inconsistencies between code and JML specification through feedback-directed random tests generation, and suggests a likely cause for each nonconformance detected. (GPL-3.0-only)
Functional Programming
Libraries that facilitate functional programming.
5427 Stars
Functional component library that provides persistent data types and functional control structures.
2119 Stars
Enhances Java 8 Streams.
2042 Stars
Extension to Java 8 that aims to fix gaps in lambda by providing numerous missing types and a rich set of sequential Stream API additions.
1572 Stars
Implements numerous basic and advanced programming abstractions that assist composition-oriented development.
1292 Stars
Monad and stream utilities, comprehensions, pattern matching, functional extensions for all JDK collections, future streams, trampolines and much more.
560 Stars
Java 8 annotation processor and framework for deriving algebraic data types constructors, pattern-matching and morphisms. (GPL-3.0-only)
474 Stars
Collection of stream utilities.
Game Development
Frameworks that support the development of games.
22353 Stars
All-round cross-platform, high-level framework.
4472 Stars
Robust framework that abstracts libraries like OpenGL/CL/AL.
3949 Stars
JavaFX Game Development Framework.
3634 Stars
Game engine for modern 3D development.
1075 Stars
Port of the renowned C++ 2D physics engine.
679 Stars
AWT-based, lightweight 2D game engine.
502 Stars
Beginner-friendly, master-ready framework for rapidly prototyping and building 2D games.
25 Stars
High-level 2D game engine with built-in physics based on Swing.
Geospatial
Libraries for working with geospatial data and algorithms.
4514 Stars
Road-routing engine. Used as a Java library or standalone web service.
1591 Stars
Library that provides tools for geospatial data. (LGPL-2.1-only)
1116 Stars
Map rendering based on OpenStreetMap data. (LGPL-3.0-only)
924 Stars
General-purpose spatial/geospatial library.
402 Stars
GeoHash utilities in Java.
200 Stars
Spatial extension of the H2 database. (LGPL-3.0-only)
92 Stars
Library for developing geospatial applications.
64 Stars
Library for using the GeoHash algorithm.
GUI
Libraries to create modern graphical user interfaces.
2416 Stars
Successor of Swing.
665 Stars
Visual layout tool for JavaFX applications.
82 Stars
Graphical widget toolkit.
High Performance
Everything about high-performance computation, from collections to specific libraries.
16748 Stars
Inter-thread messaging library.
3421 Stars
Concurrency tools currently missing from the JDK.
2695 Stars
Data structures and utility methods that are common in high-performance applications.
2308 Stars
Collections framework inspired by Smalltalk.
1669 Stars
Fast and compact type-specific collections.
987 Stars
Carefully designed extension of the Java Collections Framework with primitive specializations and more.
946 Stars
Primitive collections.
HTTP Clients
Libraries that assist with creating HTTP requests and/or binding responses.
42315 Stars
Typesafe REST client.
9143 Stars
HTTP client binder inspired by Retrofit, JAXRS-2.0, and WebSocket.
6199 Stars
Asynchronous HTTP and WebSocket client library.
4496 Stars
Client-side IPC library that is battle-tested in the cloud.
2524 Stars
Simplified, lightweight HTTP client library.
1391 Stars
A toolset of low-level Java components focused on HTTP and associated protocols.
1351 Stars
Pluggable HTTP transport abstraction with support for java.net.HttpURLConnection, Apache HTTP Client, Android, Google App Engine, XML, Gson, Jackson and Protobuf.
282 Stars
Client-side response routing for Spring's RestTemplate.
204 Stars
HTTP client extensions library.
56 Stars
A wrapper on JDK 11's HttpClient that adds Feign-like interface among other enhancements.
IDE
Integrated development environments that try to simplify several aspects of development.
154705 Stars
Provides Java support for lightweight projects with a simple, modern workflow by using extensions from the internal marketplace.
2473 Stars
Provides integration for several Java SE and EE features, from database access to HTML5.
Imagery
Libraries that assist with the creation, evaluation or manipulation of graphical images.
31856 Stars
Multi-format 1D/2D barcode image processing library.
4914 Stars
High-quality thumbnail generation library.
1745 Stars
Collection of plugins that extend the number of supported image file formats.
1456 Stars
JNA wrapper for Tesseract OCR API.
1186 Stars
Simple, efficient and hardware-accelerated image-scaling library implemented in pure Java 2D.
309 Stars
Library that compares 2 images with the same sizes and shows the differences visually by drawing rectangles. Some parts of the image can be excluded from the comparison.
Introspection
Libraries that help make the Java introspection and reflection API easier and faster to use.
4623 Stars
Reflections scans your classpath, indexes the metadata, allows you to query it on runtime and may save and collect that information for many modules within your project.
2748 Stars
jOOR stands for jOOR Object Oriented Reflection. It is a simple wrapper for the java.lang.reflect package.
2569 Stars
ClassGraph (formerly FastClasspathScanner) is an uber-fast, ultra-lightweight, parallelized classpath scanner and module scanner for Java, Scala, Kotlin and other JVM languages.
1472 Stars
ReflectASM is a very small Java library that provides high performance reflection by using code generation.
575 Stars
Allows dynamic instantiation without default constructor, e.g. constructors which have required arguments, side effects or throw exceptions.
104 Stars
Mirror was created to bring light to a simple problem, usually named ReflectionUtil, which is on almost all projects that rely on reflection to do advanced tasks.
Job Scheduling
Libraries for scheduling background jobs.
5951 Stars
Feature-rich, open source job scheduling library that can be integrated within virtually any Java application.
3266 Stars
Makes sure that your scheduled tasks are executed at most once at the same time. If a task is being executed on one node, it acquires a lock which prevents execution of the same task from another node or thread.
2022 Stars
Job scheduling library which utilizes lambdas for fire-and-forget, delayed and recurring jobs. Guarantees execution by single scheduler instance using optimistic locking. Has features for persistence, minimal dependencies and is embeddable.
1046 Stars
Persistent and cluster-friendly scheduler.
595 Stars
Set up batch jobs with simple processing pipelines. Records are read in sequence from a data source, processed in pipeline and written in batches to a data sink.
265 Stars
Lightweight framework to simply define jobs, define triggers and start the scheduler.
121 Stars
Simple library with minimal footprint and straightforward API.
JSON
Libraries for serializing and deserializing JSON to and from Java objects.
25538 Stars
Very fast processor with no additional dependencies and full data binding.
22709 Stars
Serializes objects to JSON and vice versa. Good performance with on-the-fly usage.
9344 Stars
Modern JSON library, less opinionated and uses built-in types like List and Map.
8621 Stars
Similar to GSON, but offers performance gains if you need to instantiate the library more often.
8423 Stars
Extract data from JSON using XPATH-like syntax.
3215 Stars
JSON parsing and serializing library based on Jackson's streaming API. Outperforms GSON & Jackson's library.
1480 Stars
Fast and flexible library with iterator and lazy parsing API.
1439 Stars
JSON to JSON transformation tool.
971 Stars
JSON library with advanced compile time databinding.
459 Stars
High-performance JSON parser, 2x faster than Jackson.
393 Stars
Set of Jackson modules for Java 8 datatypes and features.
312 Stars
Convert Java to JSON. Convert JSON to Java. Pretty print JSON. Java JSON serializer.
280 Stars
Streaming JsonPath processor dedicated to processing big and complicated JSON data.
240 Stars
Open-source Jackson module to support JSON serialization and deserialization of JavaMoney data types.
217 Stars
Powerful and easy-to-use Java-to-JSON conversion library.
193 Stars
Binding layer between classes and JSON documents similar to JAXB.
42 Stars
Reflection-free Json binding via source code generation with Jackson-like annotations.
JVM and JDK
Current implementations of the JVM/JDK.
19387 Stars
Polyglot embeddable JVM. (GPL-2.0-only WITH Classpath-exception-2.0)
17580 Stars
Open JDK community home. (GPL-2.0-only WITH Classpath-exception-2.0)
4053 Stars
Downstream version of OpenJDK optimized for online e-commerce, financial, logistics applications.
3190 Stars
High performance, enterprise-calibre, flexibly licensed, openly-governed cross-platform JVM extending and augmenting the runtime technology components from the Eclipse OMR and OpenJDK project.
2965 Stars
Community-driven OpenJDK builds, including both HotSpot and OpenJ9.
2080 Stars
No-cost, multiplatform, production-ready distribution of OpenJDK by Amazon. (GPL-2.0-only WITH Classpath-exception-2.0)
1592 Stars
VM with non-blocking, concurrent GC for iOS. (GPL-2.0-only WITH Classpath-exception-2.0)
1213 Stars
JVM with JIT, AOT modes and iOS port.
470 Stars
SAP's no-cost, rigorously tested and JCK-verified OpenJDK friendly fork. (GPL-2.0-only WITH Classpath-exception-2.0)
256 Stars
Built from OpenJDK, thoroughly tested and passed the JCK. (GPL-2.0-only WITH Classpath-exception-2.0)
248 Stars
OpenJDK builds for Windows, Linux, and macOS. (GPL-2.0-only WITH Classpath-exception-2.0)
Logging
Libraries that log the behavior of an application.
19033 Stars
Analyzes and visualizes log files. Some features require payment.
13838 Stars
Tool for managing log files.
6921 Stars
Open-source aggregator suited for extended role and permission management. (GPL-3.0-only)
3217 Stars
Complete rewrite with a powerful plugin and configuration architecture.
2839 Stars
Robust logging library with interesting configuration options via Groovy.
2210 Stars
Abstraction layer/simple logging facade.
1954 Stars
Enables logging for all JDBC transactions without changes to the code.
1660 Stars
Extensible, open-source library for HTTP request and response logging.
641 Stars
Lightweight logging framework with static logger class.
180 Stars
Collection of libraries that build on top of OpenTracing and provide extensions and plugins to existing instrumentations.
52 Stars
API designed around structured logging, rich context, and conditional logging. There are Logback and Log4J2 implementations, but Echopraxia's API is completely dependency-free, meaning it can be implemented with any logging API.
Machine Learning
Tools that provide specific statistical algorithms for learning from data.
22561 Stars
Fast, reliable, large-scale data processing engine.
13295 Stars
Distributed and multi-threaded deep learning library.
9365 Stars
Analytics engine for statistics over big data.
5866 Stars
Statistical Machine Intelligence and Learning Engine provides a set of machine learning algorithms and a visualization library.
3672 Stars
High-level and engine-agnostic framework for deep learning.
2676 Stars
CLI tool to transpile models into native code.
2109 Stars
Scalable algorithms focused on collaborative filtering, clustering and classification.
1791 Stars
Framework for building real-time, large-scale machine learning applications. Includes end-to-end applications for collaborative filtering, classification, regression, and clustering.
1488 Stars
Cloud native streaming and complex event processing engine.
1208 Stars
Provides tools for classification, regression, clustering, model development and interfaces with other libraries such as scikit-learn, pytorch and TensorFlow.
1091 Stars
Provides several algorithms and pre-trained models for natural language processing.
778 Stars
Algorithms for pre-processing, classification, regression, and clustering with support for multi-threaded execution. (GPL-3.0-only)
448 Stars
High-performance mathematics, linear algebra and optimisation needed for data science, machine learning and scientific computing.
176 Stars
Collection of algorithms for data mining tasks ranging from pre-processing to visualization. (GPL-3.0-only)
61 Stars
Seamlessly integrate with remote deep learning and language models programmatically.
Messaging
Tools that help send messages between clients to ensure protocol independency.
26578 Stars
High-throughput distributed messaging system.
24519 Stars
Simple publish/subscribe event bus.
20179 Stars
Fast, reliable, and scalable distributed messaging platform.
13468 Stars
Distributed pub/sub-messaging system.
6870 Stars
Efficient, reliable, unicast and multicast message transport.
5191 Stars
Glues together different transport APIs via Enterprise Integration Patterns.
2360 Stars
Cross-platform XMPP client library.
2297 Stars
Implementation of ZeroMQ.
2223 Stars
Message broker that implements JMS and converts synchronous to asynchronous communication.
1202 Stars
RabbitMQ client.
928 Stars
Provides a RESTful API on top of Kafka.
777 Stars
Fast and reliable message broker built on top of Kafka.
514 Stars
NATS client.
126 Stars
Apache Qpid makes messaging tools that speak AMQP and support many languages and platforms.
39 Stars
Simple, lightweight, and performant dispatch library for decoupling messages (requests and events) and message handlers.
Microservice
Tools for creating and managing microservices.
28304 Stars
Dynamic service discovery, configuration and service management platform for building cloud native applications.
21696 Stars
Flow control component enabling reliability, resilience and monitoring for microservices.
12711 Stars
Kubernetes stack tailored for the HotSpot and Graal VM.
12099 Stars
REST-based service registry for resilient load balancing and failover.
5888 Stars
Modern full-stack framework with focus on modularity, minimal memory footprint and startup time.
4550 Stars
Asynchronous RPC/REST client/server library built on top of Java 8, Netty, HTTP/2, Thrift and gRPC.
4221 Stars
Java libraries for using OpenAI's GPT-3 API.
4002 Stars
Wrapping of the Discord REST API and its WebSocket events.
3279 Stars
Two-style approach for writing microservices: Functional-reactive and as an implementation of MicroProfile.
3208 Stars
Client provides access to the full Kubernetes & OpenShift REST APIs via a fluent DSL.
1649 Stars
Libraries for writing composable microservices.
764 Stars
Lightweight and fast library for complex high-load distributed applications and Memcached-like solutions.
416 Stars
Client for the Consul API: a distributed, highly available and datacenter-aware registry/discovery service.
Miscellaneous
Everything else.
85200 Stars
Implementation and explanation of the most common design patterns.
19995 Stars
No-nonsense implementation of FizzBuzz made by serious businessmen for serious business purposes. (No explicit license)
16540 Stars
Modern Java - A Guide to Java 8
Popular Java 8 guide.
10060 Stars
Tool for working with messy data: cleaning, transforming, extending it with web services and linking it to databases.
5968 Stars
Java-to-Objective-C translator for porting Android libraries to iOS.
5215 Stars
Browser extension which allows to navigate through code on GitHub more efficiently.
2343 Stars
In-memory file system.
2009 Stars
High performance HTTP proxy atop Netty's event-based networking library.
1969 Stars
Wrapper around AWS' API.
1864 Stars
Library for the Svix API to send webhooks and verify signatures.
1660 Stars
Ultra-fast, SQL-like queries on Java collections.
1586 Stars
Analogue of Gradle Wrapper for Maven, allows building projects without installing maven.
1414 Stars
Source transpiler to TypeScript/JavaScript.
1336 Stars
Feature Flags for Java.
1203 Stars
Framework for building chatbots. (GPL-3.0-only)
1150 Stars
Mailing with a clean and fluent API.
1091 Stars
Static website generator.
893 Stars
Implementation of the Feature Toggles pattern.
862 Stars
Extensions for Maven 3.3.1+ that allows writing the POM model in dialects other than XML.
635 Stars
Basic currency and money classes and algorithms not provided by the JDK.
601 Stars
Tools for resolving generic types.
484 Stars
Simple wrapper for the org.w3c.dom package, to allow for fluent XML document creation and manipulation with an API inspired by jQuery.
434 Stars
Open-source, reverse-proxy framework.
376 Stars
Framework for fragment-based message processing. (Apache-2.0 OR LGPL-3.0-or-later)
372 Stars
Small utility library for using handlers and commands with pipelines.
351 Stars
Detect uses of legacy Java APIs.
323 Stars
Obfuscation via renaming and shrinking.
213 Stars
JCuda offers Java bindings for CUDA and CUDA-related libraries.
153 Stars
Lightweight, small and customizable FTP server.
73 Stars
Processes XML by using annotations or XPath within code.
21 Stars
RR4J is a tool that records java bytecode execution and later allows developers to replay locally.
15 Stars
Source code obfuscator.
Mobile Development
Tools for creating or managing mobile applications.
1592 Stars
Cross-platform solution for writing native mobile apps. (GPL-2.0-only WITH Classpath-exception-2.0)
569 Stars
Open-source, cross-platform engine to develop native mobile (iOS, Android, etc.) apps.
Monitoring
Tools that monitor applications in production.
16557 Stars
Distributed tracing system which gathers timing data needed to troubleshoot latency problems in microservice architectures.
13100 Stars
Open-source APM tool.
7780 Stars
Expose metrics via JMX or HTTP and send them to a database.
4955 Stars
Dynamic and observable thread pool framework.
3950 Stars
Real-time monitoring system with custom-monitor and agentless.
2887 Stars
Performance monitoring and profiling.
2094 Stars
Provides a multi-dimensional data model, DSL, autonomous server nodes and much more.
1709 Stars
Open-source performance monitoring and transaction tracing for JVM apps.
1703 Stars
Connect to multiple JVMs and query them for their attributes via JMX. Its query language is based on JSON, which allows non-Java programmers to access the JVM attributes. Supports different output writes, including Graphite, Ganglia, and StatsD.
1158 Stars
Open-source Java APM.
1057 Stars
Integration with [Sentry](https://github.com/getsentry/sentry), an application error tracking and performance analysis platform.
791 Stars
JMX over REST.
567 Stars
Combines the power of AOP with monitoring and/or logging tools.
537 Stars
Captures detailed run-time information via hooks that can be changed on the fly. It supports tracing over multiple systems via the OpenTracing API and can correlate the data with end user monitoring.
497 Stars
Modern monitoring & analytics.
490 Stars
Jaeger client.
155 Stars
Lightweight platform monitoring tool for Java VMs.
154 Stars
Remote developer console from the browser for Java 8 via bytecode injection.
53 Stars
Out of the box monitoring of Failsafe Circuit Breaker in Spring-Boot environment.
21 Stars
Performance monitor with distributing transaction tracing for JVM apps.
Native
For working with platform-specific native libraries.
8141 Stars
Work with native libraries without writing JNI. Also provides interfaces to common system libraries.
4278 Stars
Provides efficient and easy access to native C++.
1173 Stars
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](http://openjdk.java.net/projects/panama).
453 Stars
Converts bytecode to OpenCL which allows execution on GPUs.
Natural Language Processing
Libraries that specialize in processing text.
9302 Stars
Provides a set of fundamental tools for tasks like tagging, named entity recognition, and sentiment analysis. (GPL-3.0-or-later)
469 Stars
Provides common annotators for plain text input. (Research and Academic Use License)
197 Stars
Collection of reusable NLP tools for linguistic pre-processing, machine learning, lexical resources, etc.
Networking
Libraries for building network servers.
39722 Stars
High-performance RPC framework.
32283 Stars
Framework for building high-performance network applications.
10980 Stars
RPC framework based on protobuf and HTTP/2.
3477 Stars
Web server providing both blocking and non-blocking APIs based on NIO. Used as a network layer in WildFly. (LGPL-2.1-only)
2406 Stars
Programmatically use SSH, SCP or SFTP.
1791 Stars
Provides a clean and simple API for efficient TCP and UDP client/server network communication using NIO and Kryo.
893 Stars
Abstract, event-driven async I/O API for network operations over TCP/IP and UDP/IP via Java NIO.
866 Stars
Framework built on Netty with APIs tailored to specific protocols and support for multiple programming paradigms.
602 Stars
Integrates standard Java web-related APIs with Quasar fibers and actors.
230 Stars
Easy-to-use, annotation-based library for creating Thrift clients and serializable types.
171 Stars
Implements a ByteChannel interface over SSLEngine, enabling easy-to-use (socket-like) TLS.
148 Stars
High throughput data ingestion logger to Fluentd and Fluent Bit.
143 Stars
NIO framework. Used as a network layer in Glassfish.
28 Stars
Represent, parse and encode URNs, as in RFC 2141. (GPL-3.0-only)
11 Stars
Client for server-sent events (SSE).
ORM
APIs that handle the persistence of objects.
19183 Stars
Couples objects with stored procedures or SQL statements.
5640 Stars
Robust and widely used, with an active community. (LGPL-2.1-only)
1428 Stars
Provides simple and fast data access.
1238 Stars
ActiveRecord ORM for rapid development and convention over configuration.
423 Stars
Simple database and CSV mapper.
402 Stars
Database access framework that verifies and generates source code at compile time using annotation processing as well as native SQL templates called two-way SQL.
390 Stars
Language-natural persistence layer.
302 Stars
Provides a clean, static API for data access. Also includes a GUI Modeler for working with database mappings, and DB reverse engineering and generation.
178 Stars
Supports a number of persistence standards: JPA, JAXB, JCA and SDO.
PaaS
Java platform as a service.
Tools to help with PDF files.
3027 Stars
Open-source iText fork. (LGPL-3.0-only & MPL-2.0)
2262 Stars
Toolbox for creating and manipulating PDFs.
1875 Stars
XML/XHTML and CSS 2.1 renderer. (LGPL-2.1-or-later)
1784 Stars
Properly supports modern PDF standards based on flyingsaucer and Apache PDFBox.
1678 Stars
Extracts tables from PDF files.
1545 Stars
Creates PDF files programmatically.
882 Stars
Complex reporting engine. (LGPL-3.0-only)
395 Stars
Report engine for creating PDF and other formats (DOCX, XLSX, HTML, etc) using Eclipse-based visual editor.
239 Stars
Abstraction layer to JasperReports. (LGPL-3.0-only)
184 Stars
Simplifies JasperReports. (LGPL-3.0-only)
162 Stars
Creates PDFs from XSL-FO.
Performance analysis
Tools for performance analysis, profiling and benchmarking.
2965 Stars
Analyze the JIT compiler optimisations made by the HotSpot JVM.
1859 Stars
Harness for building, running, and analysing nano/micro/milli/macro benchmarks written in Java and other languages targeting the JVM. (GPL-2.0 only WITH Classpath-exception-2.0)
1240 Stars
Low-overhead, bias-free sampling profiler.
674 Stars
Logs and records platform JVM stalls.
447 Stars
Utilities for latency measurement and reporting.
Apache Commons
Reusable, open source Java software.
2594 Stars
Provides extra functionality for classes in java.lang.
962 Stars
Collection of I/O utilities.
646 Stars
Extends or augments the Java Collections Framework.
542 Stars
Lightweight, self-contained mathematics and statistics components.
491 Stars
Generic object pooling component.
432 Stars
General encoding/decoding algorithms, e.g. phonetic, base64 or URL.
389 Stars
Image library.
352 Stars
JDBC helper library.
350 Stars
Component for reading and writing comma separated value files.
324 Stars
Database connection pooling services.
316 Stars
Command-line arguments parser.
302 Stars
Defines an API for working with tar, zip and bzip2 files.
263 Stars
Easy-to-use wrappers around the Java reflection and introspection APIs.
233 Stars
Collection of network utilities and protocol implementations.
229 Stars
Byte Code Engineering Library - analyze, create, and manipulate Java class files.
220 Stars
File upload capability for your servlets and web applications.
212 Stars
Virtual File System component for treating files, FTP, SMB, ZIP and such like as a single logical file system.
189 Stars
Framework to define validators and validation rules in an xml file.
186 Stars
Reading of configuration/preferences files in various formats.
171 Stars
Expression language which extends the Expression Language of the JSTL.
136 Stars
Library for sending e-mail from Java.
136 Stars
Wrapper around a variety of logging API implementations.
129 Stars
API for dealing with external process execution and environment management in Java.
90 Stars
Java Caching System.
89 Stars
Alternative invocation mechanism for unix-daemon-like java code.
81 Stars
Object-graph navigation language.
68 Stars
Chain of Responsibility pattern implementation.
50 Stars
XML-to-Java-object mapping utility.
46 Stars
Commons Rng provides implementations of pseudo-random numbers generators.
43 Stars
Implementation of the State Chart XML specification aimed at creating and maintaining a Java SCXML engine.
39 Stars
Common implementation of RDF 1.1 that could be implemented by systems on the JVM.
28 Stars
Utilities for manipulating Java Beans using the XPath syntax.
25 Stars
General purpose graph APIs and algorithms.
25 Stars
Library for creating dynamic proxies.
21 Stars
Bean Scripting Framework - interface to scripting languages, including JSR-223.
21 Stars
Function that can be manipulated as an object, or an object representing a single, generic function.
20 Stars
Provides an easy way to enhance (weave) compiled bytecode.
15 Stars
XML based scripting and processing engine.
13 Stars
Java Compiler Interface.
Other
Other kinds of platforms
3564 Stars
Fast, lightweight and productive microservices framework with built-in [security](https://github.com/networknt/light-oauth2/).
1338 Stars
High-level framework for developing enterprise applications with a rich web interface, based on Spring, EclipseLink and Vaadin.
225 Stars
Open-source business application platform for rapid configuration/development of CRM, ERP, LMS and other applications.
Processes
Libraries that help the management of operating system processes.
864 Stars
Provides a unified API to Apache Commons Exec and ProcessBuilder.
123 Stars
Stops processes started from Java or the system processes via PID.
29 Stars
Convenient API around Apache Commons Exec.
Reactive libraries
Libraries for developing reactive applications.
47381 Stars
Allows for composing asynchronous and event-based programs using observable sequences.
13904 Stars
Polyglot event-driven application framework.
12851 Stars
Toolkit and runtime for building concurrent, distributed, fault-tolerant and event-driven applications.
4737 Stars
Library for building reactive fast-data applications.
4713 Stars
Provides a standard for asynchronous stream processing with non-blocking backpressure.
REST Frameworks
Frameworks specifically for creating RESTful services.
9564 Stars
Sinatra inspired framework.
8437 Stars
Opinionated framework for setting up modern web applications with Jetty, Jackson, Jersey and Metrics.
2957 Stars
Automates the generation of API documentation using Spring Boot projects.
2368 Stars
Framework for building robust, scalable RESTful architectures using typesafe bindings and asynchronous, non-blocking IO with an end-to-end developer workflow that promotes clean practices, uniform interface design and consistent data modeling.
1626 Stars
Simple, secure and extremely fast framework consisting of an embedded HTTP server, GUI components and dependency injection.
1068 Stars
Fully certified and portable implementation of the JAX-RS specification.
969 Stars
Opinionated framework for JSON- or GraphQL-APIs based on a JPA data model.
942 Stars
Convenient, extensible microservices plugin system for Spring & Spring Boot. With more than 30 plugins and growing, it supports both micro-monolith and pure microservices styles.
937 Stars
Thin wrapper on the JBoss Netty HTTP stack that provides scaling and performance.
663 Stars
JAX-RS reference implementation.
641 Stars
Pioneering framework with powerful routing and filtering capabilities, and a unified client and server API.
281 Stars
Implementation of the JSON API specification to build resource-oriented REST endpoints with sorting, filtering, paging, linking, object graphs, type-safety, bulk updates, integrations and more.
Science
Libraries for scientific computing, analysis and visualization.
3383 Stars
Includes a data-frame, an embedded column store, and hundreds of methods to transform, summarize, or filter data.
2465 Stars
Graph library that provides mathematical graph-theory objects and algorithms.
1441 Stars
Light-weight library for plotting data. Many customizable chart types are available.
1117 Stars
2D chart library for Swing, JavaFX and server-side applications. (LGPL-2.1-only)
655 Stars
Library for visualizing (mainly Swing) and interacting with node-edge graphs.
559 Stars
Facilitates processing biological data by providing algorithms, file format parsers, sequencing and 3D visualization commonly used in bioinformatics.
455 Stars
Scientific charting library with focus on performance optimised real-time data visualisation at 25 Hz update rates for large data sets.
394 Stars
Library for modeling and analyzing dynamic graphs.
238 Stars
Provides a versatile two-dimensional memory efficient tabular data structure called a DataFrame to enable efficient in-memory analytics for scientific computing on the JVM.
124 Stars
Modular, light and easy graph framework for theoretic algorithms.
122 Stars
Library for creating, manipulating and solving Boolean and Pseudo-Boolean formulas.
104 Stars
Generates a wide variety of 3D charts that can be displayed with Swing and JavaFX or exported to PDF, SVG, PNG and JPEG. (GPL-3.0-only)
70 Stars
Library for geophysical scientific computation, visualization and digital signal analysis.
Search
Engines that index documents for search and analysis.
66353 Stars
Distributed, multitenant-capable, full-text search engine with a RESTful web interface and schema-free JSON documents.
2170 Stars
High-performance, full-featured, cross-platform, text search engine library.
934 Stars
Enterprise search engine optimized for high-volume traffic.
49 Stars
Simple and light full text indexing and searching library.
Security
Libraries that handle security, authentication, authorization or session management.
18618 Stars
Integrated SSO and IDM for browser apps and RESTful web services.
13407 Stars
Provides a simple and misuse-proof API for common cryptographic tasks.
10275 Stars
Multiplatform, transparent, client-side encryption of files in the cloud. (GPL-3.0-only)
9591 Stars
JSON web token for Java and Android.
5641 Stars
Detects publicly disclosed vulnerabilities contained within a project's dependencies.
4223 Stars
Performs authentication, authorization, cryptography and session management.
2613 Stars
System for distributing and managing secrets.
2351 Stars
Security engine.
2092 Stars
All-purpose cryptographic library and JCA provider offering a wide range of functions, from basic helpers to PGP/SMIME operations.
1784 Stars
Multi-platform high-level cryptographic library provides easy-to-use encryption for protecting sensitive data: secure messaging with forward secrecy, secure data storage (AES256GCM); suits for building end-to-end encrypted applications.
898 Stars
Fine-grained authorization for applications with support for RBAC, ABAC, and ReBAC.
679 Stars
Access management solution that includes authentication, SSO, authorization, federation, entitlements and web services security.
441 Stars
High-level SSL context builder for configuring HTTP clients with SSL/TLS.
311 Stars
User-friendly cryptographic library that supports Argon2, Bcrypt, Scrypt, PBKDF2 and various other cryptographic hash functions.
278 Stars
Advanced password strength estimation.
261 Stars
Enforce password policy by validating candidate passwords against a configurable rule set.
211 Stars
Runtime application that repels application security risks included in the OWASP Top 10, including SQL injection, cross-site scripting, cross-site request forgery, data tampering, and brute force attacks.
209 Stars
Binding for the Networking and Cryptography (NaCl) library.
187 Stars
JSON Web Key Set parser.
151 Stars
One-time password generator library according to RFC 4226 (HOTP) and RFC 6238 (TOTP).
105 Stars
Provides permission-based authorization services.
44 Stars
Fluent Builder API for JCA and JSSE classes and especially X.509 certificates.
7 Stars
Easily create and parse JSON Web Tokens and create customized JWT validators using a fluent API.
Serialization
Libraries that handle serialization with high efficiency.
21578 Stars
Memory-efficient serialization library that can access serialized data without unpacking and parsing it.
5979 Stars
Fast and efficient object graph serialization framework.
1553 Stars
JDK-compatible, high-performance object graph serialization.
1367 Stars
Efficient binary serialization format.
16 Stars
Serializing objects in the PHP serialization format.
0 Stars
A blazing fast multi-language serialization framework powered by jit and zero-copy.
Server
Servers specifically used to deploy applications.
7119 Stars
Robust, all-round server for Servlet and JSP.
6753 Stars
Tiny, easily embeddable HTTP server.
3703 Stars
Provides a Web server and javax.servlet container, plus support for HTTP/2, WebSocket, OSGi, JMX, JNDI, JAAS and many other integrations.
2954 Stars
Formerly known as JBoss and developed by Red Hat with extensive Java EE support. (LGPL-2.1-only)
430 Stars
Tomcat plus Java EE.
Template Engine
Tools that substitute expressions in a template.
2670 Stars
Aims to be a substitute for JSP and works for XML files.
1413 Stars
Logicless and semantic Mustache templates.
1047 Stars
Inspired by Twig and separates itself with its inheritance feature and its easy-to-read syntax. It ships with built-in autoescaping for security and it includes integrated support for internationalization.
909 Stars
Library to generate text output (HTML web pages, e-mails, configuration files, source code, etc.) based on templates and changing data.
908 Stars
Template engine for generating source code, web pages, emails, or any other formatted text output.
705 Stars
Implementation of Pug (formerly known as Jade).
704 Stars
Optimized, memory efficient and speedy template engine producing statically typed, plain objects.
635 Stars
Compiles to classes, and uses an easy syntax, several features to make development easier and provides fast execution and a small footprint.
298 Stars
Modular, configurable and fully tested template engine.
167 Stars
Typesafe Mustache templating engine.
53 Stars
Extendable template engine embedded into Maven/JavaDoc, supporting multiple extensions (Groovy, Ruby, JavaScript, JShell, PlantUml) with support for snippet handling.
Testing
Tools that test from model to the view.
BDD
Testing for the software development process that emerged from TDD and was heavily influenced by DDD and OOAD.
2640 Stars
Provides a way to describe features in a plain language which customers can understand.
701 Stars
Automated Acceptance testing and reporting library that works with Cucumber, JBehave and JUnit to make it easier to write high quality executable specifications.
419 Stars
Provides a fluent API which allows for simpler composition.
252 Stars
Aims to provide a fluent API to write tests in long and descriptive sentences that read like plain English.
158 Stars
Extensively configurable framework that describes stories.
106 Stars
Collection of Gherkin steps for REST-service testing using Cucumber.
46 Stars
Follows a Jasmine-like syntax.
Fixtures
Everything related to the creation and handling of random data.
4438 Stars
Port of Ruby's fake data generator.
733 Stars
Fake data generator.
672 Stars
Automates data setup in unit tests by generating fully-populated, reproducible objects. Includes JUnit 5 extension.
522 Stars
Another fake data generator.
439 Stars
Generates fake objects from a template.
171 Stars
JUnit test runner and plugins for running JUnit tests with pseudo-randomness.
112 Stars
Sets up beans from YAML fixtures.
Frameworks
Provide environments to run tests for a specific use case.
7657 Stars
Functional testing and performance measurements.
6156 Stars
Load testing tool designed for ease of use, maintainability and high performance.
6019 Stars
Common testing framework.
2958 Stars
Test library for specifying and asserting architecture rules.
1595 Stars
Fast mutation-testing framework for evaluating fault-detection abilities of existing JUnit or TestNG test suites.
1036 Stars
Consumer-driven contract testing.
492 Stars
Engine for property-based testing built on JUnit 5.
431 Stars
Integration testing framework that focuses on both client- and server-side messaging.
359 Stars
Integration and functional testing platform for Java EE containers.
Matchers
Libraries that provide custom matchers.
2671 Stars
Google's fluent assertion and proposition framework.
2471 Stars
Fluent assertions that improve readability.
2072 Stars
Matchers that can be combined to create flexible expressions of intent.
953 Stars
Simplifies testing JSON strings.
827 Stars
Library that simplifies JSON comparison in tests.
284 Stars
Simplifies testing for XML output.
Miscellaneous
Other stuff related to testing.
7530 Stars
Provides throwaway instances of common databases, Selenium web browsers, or anything else that can run in a Docker container.
318 Stars
Captures log entries for unit testing purposes.
241 Stars
TestNG-like data provider/runner for JUnit.
236 Stars
Reports whether instances of a given class are immutable.
71 Stars
Tests if a request/response matches a given RAML definition.
52 Stars
Automatically performs tests on basic POJO methods. (LGPL-3.0-only)
26 Stars
Captures console output for unit testing purposes.
10 Stars
Captures log entries and provides assertions for unit and integration testing.
Mocking
Tools which mock collaborators to help testing single, isolated units.
14400 Stars
Mocking framework that lets you write tests with a clean and simple API.
5929 Stars
Stubs and mocks web services.
4362 Stars
Allows mocking of systems integrated with HTTPS.
4280 Stars
Concise web services for stubs and mocks.
4107 Stars
Mocks static methods, constructors, final classes and methods, private methods, and removal of static initializers.
455 Stars
Integration testing, API mocking and faking, and code coverage.
Utility
Libraries which provide general utility functions.
48926 Stars
Collections, caching, primitives support, concurrency libraries, common annotations, string processing, I/O, and more.
34093 Stars
Allows to troubleshoot production issues for applications without modifying code or restarting servers.
5580 Stars
Cross-platform for visualizing and manipulating large graph networks. (GPL-3.0-only)
2608 Stars
Library that helps with constructing difficult regular expressions.
2055 Stars
Rate limiting library based on token-bucket algorithm.
1712 Stars
Bulk data loader that helps data transfer between various databases, storages, file formats, and cloud services.
1311 Stars
Java/JavaFX tool capable of powerful ETL and data visualization.
1150 Stars
Utilities for text or data comparison and patching.
982 Stars
Provides simple APIs to access any Amazon S3-compatible object storage server.
923 Stars
Provides a shell into a JVM that's running CRaSH. Used by Spring Boot and others. (LGPL-2.1-or-later)
904 Stars
Provides an ontology editor and a framework to build knowledge-based systems.
716 Stars
Collection of object-oriented primitives.
506 Stars
Port of Underscore.js functions.
42 Stars
Lightweight, pure Java library implementing the Git version control system.
33 Stars
Generates postman collection, environment and integration tests from java code.
27 Stars
Micro library to watch for directory file system changes, simplifying java.nio.file.WatchService.
Version Managers
Utilities that help create the development shell environment and switch between different Java versions.
5691 Stars
Java Version Manager inspired by RVM and rbenv. Supports UNIX-based platforms.
5297 Stars
Java Version Manager inspired by rbenv. Can configure globally or per project. Tested on Debian and macOS.
2790 Stars
Java Version Manager inspired by nvm. Supports macOS, Linux and Windows.
Web Crawling
Libraries that analyze the content of websites.
11070 Stars
Scalable crawler with downloading, url management, content extraction and persistent.
10463 Stars
Scrapes, parses, manipulates and cleans HTML.
4470 Stars
Simple and lightweight web crawler.
2736 Stars
Highly extensible, highly scalable web crawler for production environments.
833 Stars
SDK for building low-latency and scalable web crawlers.
Web Frameworks
Frameworks that handle the communication between the layers of a web application.
12485 Stars
Built on Akka, it provides predictable and minimal resource consumption (CPU, memory, threads) for highly-scalable applications in Java and Scala.
6905 Stars
Microframework for web applications.
5817 Stars
Lightweight, modular framework that aims to be elegant and simple.
1929 Stars
Set of libraries that facilitate fast, efficient, evolvable and well-tested HTTP applications.
1910 Stars
Full-stack web framework.
1760 Stars
Event-driven framework that uses standard web components. Server-side architecture with Ajax on the client side.
1689 Stars
JSF framework with both free and commercial/support versions and frontend components.
1628 Stars
Scalable, fast and modular micro-framework that offers multiple programming models.
1409 Stars
Minimally opinionated framework for runnable apps.
783 Stars
Opinionated web framework which is built around the concepts of True Object-Oriented Programming and immutability.
781 Stars
Small, highly modularized, Sinatra-like framework.
764 Stars
Lightweight asynchronous framework built from the ground up for developing high-performance web applications.
705 Stars
Component-based web application framework similar to Tapestry, with a stateful GUI.
290 Stars
Asynchronous framework for rapid development of high-performance web application.
111 Stars
Component-oriented framework for creating dynamic, robust, highly scalable web applications.
About
Created by @ResamVi. You can find the code here. Theme made by Lexington Themes.