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.
7296 Stars
Code generator that simplifies mappings between different bean types, based on a convention-over-configuration approach.
2315 Stars
Intelligent object mapping library that automatically maps objects to each other.
1309 Stars
JavaBean-mapping framework that recursively copies (among other capabilities) data from one object to another.
233 Stars
Uses byte code manipulation for lightning-fast mapping. Supports annotations and API or XML configuration.
214 Stars
Annotation processor-based bean mapper.
124 Stars
Lambda and method handle-based mapping which requires code and not annotations if objects have different names.
93 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.
23873 Stars
Tool from Google that builds code quickly and reliably.
17458 Stars
Incremental builds programmed via Groovy instead of declaring XML. Works well with Maven's dependency management.
8560 Stars
Encourages the creation of small, reusable modules consisting of code and resources.
4559 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.
14931 Stars
Java 8 Jar & Android APK reverse engineering suite. (GPL-3.0-only)
6451 Stars
Further simplifies bytecode generation with a fluent API.
6343 Stars
JVM reverse engineering toolkit, essentially an IDE for Java bytecode.
4843 Stars
Bytecode generation library.
4169 Stars
Tries to simplify bytecode editing.
1542 Stars
Manipulate bytecode at runtime using real Java code.
495 Stars
Manipulate bytecode at runtime via DSL (rules); mainly for testing/troubleshooting. (LGPL-2.1-or-later)
67 Stars
Dynamically injects failure/latency at the bytecode level according to principles of chaos engineering.
58 Stars
Provides low level bytecode generation.
Caching
Libraries that provide caching facilities.
16474 Stars
High-performance, near-optimal caching library.
2040 Stars
Distributed general-purpose cache.
1239 Stars
Highly concurrent key/value datastore used for caching.
725 Stars
In-memory high performance caching library.
CLI
Libraries for everything related to the CLI.
5061 Stars
ANSI colors and styles in usage help with annotation-based POSIX/GNU/any syntax, subcommands, strong typing for both options and positional args.
2385 Stars
Easy console text-GUI library, similar to curses. (LGPL-3.0-only)
1990 Stars
Command-line argument-parsing framework with custom types and validation via implementing interfaces.
1556 Stars
Includes features from modern shells like completion or history.
1150 Stars
ANSI escape codes to format console output.
845 Stars
Annotation-based framework for parsing Git-like command-line arguments.
790 Stars
Small library to parse command-line arguments.
507 Stars
Library to draw tables in ASCII.
354 Stars
Fluent parser that uses the POSIX#getopt and GNU#getopt_long syntaxes.
349 Stars
Aids the creation of full console-based applications.
160 Stars
Graphical primitives for the console.
88 Stars
Reflectionless command line parser.
Cluster Management
Frameworks that can dynamically manage applications inside of a cluster.
823 Stars
Mesos framework that makes deployment and operations easy. It supports web services, background workers, scheduled jobs, and one-off tasks.
634 Stars
Mesos framework for long-running services and cron jobs.
Code Analysis
Tools that provide metrics and quality measurements.
30597 Stars
Provides Alibaba's coding guidelines for PMD, IDEA and Eclipse.
15166 Stars
Modern static analysis tool for verifying the correctness of code.
8540 Stars
Static analysis of coding conventions and standards. (LGPL-2.1-or-later)
6951 Stars
Catches common programming mistakes as compile-time errors.
5019 Stars
Source code analysis for finding bad coding practices.
3713 Stars
Eliminates NullPointerExceptions with low build-time overhead.
3612 Stars
Static analysis of bytecode to find potential bugs. (LGPL-2.1-only)
1795 Stars
Library for analyzing and transforming Java source code.
1167 Stars
Static analyzer for SonarQube & SonarLint. (LGPL-3.0-only)
483 Stars
Identifies and prioritizes God Classes and Highly Coupled classes.
214 Stars
Error Prone extensions: extra bug checkers and a large battery of Refaster templates.
211 Stars
Static code analysis with Neo4J-based query language. (GPL-3.0-only)
Code Coverage
Frameworks and tools that enable code coverage metrics collection for test suites.
4304 Stars
Framework that enables collection of code coverage metrics, using both offline and runtime bytecode instrumentation.
1044 Stars
Relies on offline (or static) bytecode instrumentation and class loading to collect code coverage metrics. (GPL-2.0-only)
65 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.
21838 Stars
Yeoman source code generator for Spring Boot and AngularJS.
13095 Stars
Code generator that aims to reduce verbosity.
10857 Stars
API to generate source files.
10487 Stars
Generates factory, service, and value classes.
3473 Stars
Annotation processors to generate simple, safe and consistent value objects.
835 Stars
Automatically generates the Builder pattern.
804 Stars
Companion builder class, withers and templates for Java records.
175 Stars
Simple and light code generator available as an Eclipse Plugin and also as a CLI.
145 Stars
JSR-269 code generator for algebraic data types.
144 Stars
Small framework that adds queryable properties to Java, enhancing JavaBeans.
130 Stars
Discovers files that need generated code, updates automatically and writes to the source with a convenient API.
74 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.
6223 Stars
Configuration library supporting Java properties, JSON or its human optimized superset HOCON.
3133 Stars
High-level API for Apache ZooKeeper.
921 Stars
Reduces boilerplate of properties.
612 Stars
Highly-available version-controlled service configuration repository based on Git, ZooKeeper and HTTP/2.
556 Stars
Modern configuration library for distributed apps written in Java.
407 Stars
Configuration library with support for various configuration formats and transformations.
307 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.
71 Stars
Loads yaml and properties files, supports dynamic configuration, plugins, file-watching and config event listeners.
60 Stars
Annotation-based configuration system for Java and Kotlin.
47 Stars
Twelve-factor configuration library which uses environment-specific files.
28 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.
1274 Stars
Flexible solver with Spring/Quarkus support and quickstarts for the Vehicle Routing Problem, Maintenance Scheduling, Employee Shift Scheduling and much more.
712 Stars
Off-the-shelf constraint satisfaction problem solver that uses constraint programming techniques.
356 Stars
Business planning and resource scheduling optimization solver.
222 Stars
Includes an interface for the FlatZinc language, enabling it to execute MiniZinc models. (AGPL-3.0)
CSV
Frameworks and libraries that simplify reading/writing CSV data.
920 Stars
One of the fastest and most feature-complete parsers. Also comes with parsers for TSV and fixed-width records.
593 Stars
Performance-optimized, dependency-free and RFC 4180 compliant.
527 Stars
Powerful CSV parser with support for Dozer, Joda-Time and Java 8.
194 Stars
Jackson extension for reading and writing CSV.
Data Structures
Efficient and specific data structures.
67019 Stars
Google's data interchange format.
10662 Stars
Data interchange format that originated at Facebook.
4309 Stars
Clean, lightweight protocol buffers.
3641 Stars
Fast and efficient compressed bitmap.
3041 Stars
Data interchange format with dynamic typing, untagged data, and absence of manually assigned IDs.
2463 Stars
Lightning-fast, transactional, file-based FIFO.
770 Stars
Persistent and immutable analogue of the Java Collections Framework.
720 Stars
Fast and efficient columnar storage format for Hadoop-based workloads.
563 Stars
Fast and persistent queue based on memory-mapped files.
56 Stars
Probabilistic data structure for computing union, intersection, and set cardinality in loglog space.
0 Stars
Columnar storage format based on assembly algorithms from Google's paper on Dremel.
0 Stars
Simple Binary Encoding, one of the fastest message formats around.
Database
Everything that simplifies interactions with the database.
23704 Stars
Allows for distributed and scalable data structures on top of a Redis server.
20355 Stars
High-performance JDBC connection pool.
15031 Stars
High-performance SQL database for time series. Supports InfluxDB line protocol, PostgreSQL wire protocol, and REST.
13656 Stars
High-performance, column-oriented, distributed data store.
12011 Stars
Small client for interaction with Redis, with methods for commands.
11480 Stars
Mobile database to run directly inside phones, tablets or wearables.
11242 Stars
Low latency data streaming platform for change data capture.
11050 Stars
Distributed SQL query engine for big data.
8643 Stars
Simple database migration tool.
6563 Stars
Distributed ID generate service.
6350 Stars
Generates typesafe code based on SQL schema.
4967 Stars
Database-independent library for tracking, managing and applying database schema changes.
4961 Stars
Embedded database engine that provides concurrent collections backed on disk or in off-heap memory.
4841 Stars
Typesafe unified queries.
4778 Stars
Dynamic data management framework. It contains many of the pieces that comprise a typical database management system.
4318 Stars
Small SQL database notable for its in-memory functionality.
3129 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.
2840 Stars
Efficient, in-memory (opt. persisted to disk), off-heap key-value store.
2115 Stars
Client for the Elasticsearch REST API.
2089 Stars
Database access library that utilizes Java 8's Stream API for querying.
2025 Stars
Convenient abstraction of JDBC.
1963 Stars
Distributed, schema on-the-fly, ANSI SQL query engine for Big Data exploration.
1217 Stars
Highly concurrent transactional schema-less and ACID-compliant embedded database.
1119 Stars
Brings metrics and failover strategies to the most common connection pooling solutions.
1038 Stars
High-performance relational database layer over HBase for low-latency applications.
662 Stars
Typesafe database queries via symbolic execution of Java 8 Lambdas (on top of JPA or jOOQ).
532 Stars
Universal, flexible, high-performance distributed ID generator.
440 Stars
NoSQL document database and application platform. (LGPL-2.1-only)
391 Stars
LDAPv3 compliant directory service, developed for the Java platform, providing a high performance, highly available, and secure store for the identities.
205 Stars
ArangoDB Java driver.
137 Stars
Client library for etcd.
109 Stars
JDBC connection pool library with advanced performance monitoring capabilities.
98 Stars
Spring Data JPA MongoDB Expressions
Allows you to use MongoDB query language to query your relational database.
19 Stars
Build JPA Criteria queries using a Stream-like API.
13 Stars
Launcher for MariaDB that requires no installation or external dependencies.
13 Stars
Lightweight ORM with database reverse engineering features.
0 Stars
Lettuce is a scalable Redis client for building non-blocking Reactive applications.
Date and Time
Libraries related to handling date and time.
785 Stars
Parse and build iCalendar [RFC 5545](https://tools.ietf.org/html/rfc5545) data models.
451 Stars
Advanced date and time library. (LGPL-2.1-only)
402 Stars
Additional date-time classes that complement those in JDK 8.
189 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.
17532 Stars
Compile-time injection framework without reflection.
12581 Stars
Lightweight and opinionated framework that completes Dagger.
826 Stars
Extensions and utilities that enhance Google Guice.
357 Stars
Ultra-lightweight, JSR-330-compliant dependency injection library.
256 Stars
Microservice-focused compile-time injection framework without reflection.
151 Stars
CDI extension framework.
113 Stars
Lightweight and dynamic dependency injection framework.
57 Stars
Lightweight dependency injection framework. (LGPL-3.0-only)
Development
Augmentation of the development process at a fundamental level.
5730 Stars
Parse, modify and generate Java code.
2516 Stars
Re-energizes Java with powerful features like type-safe metaprogramming, structural typing and extension methods.
2427 Stars
Unlimited runtime class and resource redefinition. (GPL-2.0-only)
1809 Stars
JVM modification that allows unlimited redefinition of loaded classes at runtime. (GPL-2.0-only)
331 Stars
Seamless aspect-oriented programming extension.
293 Stars
Symbol solver.
137 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.
97 Stars
Allows checked exceptions in functional interfaces and converts exceptions to Optional return.
76 Stars
Ignores checked exceptions without bytecode manipulation. Can also be used inside Java 8 stream operations.
27 Stars
Enable infinite recursion using tail call optimization.
Distributed Applications
Libraries and frameworks for writing distributed and fault-tolerant applications.
13674 Stars
Gateway service that provides dynamic routing, monitoring, resiliency, security, and more.
12432 Stars
Coordination service with distributed configuration, synchronization, and naming registry for large distributed systems.
10070 Stars
Functional fault tolerance library.
6615 Stars
Realtime computation system.
6284 Stars
Highly scalable in-memory datagrid with a free open-source version.
4570 Stars
Lightweight threads and actors for the JVM.
4244 Stars
Simple failure handling with retries and circuit breakers.
2361 Stars
Fault-tolerant distributed coordination framework.
2300 Stars
In-memory data management system that provides reliable asynchronous event notifications and guaranteed message delivery.
1041 Stars
Toolkit for reliable messaging and cluster creation.
621 Stars
Embeddable Cluster-Membership library based on SWIM and gossip protocol.
79 Stars
High-performance reverse proxy server with specialized session management and credential replay functionality.
44 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.
473 Stars
Provides transactions for REST, SOA and microservices with support for JTA and XA.
243 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.
2588 Stars
Packs JARs, assets and the JVM for native distribution on Windows, Linux and macOS.
1152 Stars
Simple and powerful packaging and deployment. A fat JAR on steroids, or a "Docker for Java" that supports JVM-optimized containers.
562 Stars
Binary artifact management toolkit which hosts them on the file system or S3.
516 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.
482 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.
374 Stars
Deploy desktop apps as native Mac, Windows or Linux bundles.
330 Stars
Setup authoring tool for cross-platform deployments.
128 Stars
really-executable-jars-maven-plugin
Maven plugin for making self-executing JARs.
45 Stars
Builds optimized runtimes over HTTP.
0 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.
Document Processing
Libraries that assist with processing office document formats.
2187 Stars
Create and manipulate Microsoft Open XML files.
2007 Stars
Supports OOXML (XLSX, DOCX, PPTX) as well as OLE2 (XLS, DOC or PPT).
767 Stars
High performance library to read and write large Excel (XLSX) worksheets.
571 Stars
API for document format conversion using third-party converters such as MS Word.
81 Stars
Annotation-based API for reading data from Excel sheets into POJOs with focus on reduced overhead.
Financial
Libraries related to the financial domain.
2173 Stars
Library for technical analysis.
855 Stars
Integration with the Stripe API.
605 Stars
Trading bot framework.
502 Stars
Platform for trading venues.
332 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.
1058 Stars
Pluggable type systems. Includes nullness types, physical units, immutability types and more. (GPL-2.0-only WITH Classpath-exception-2.0)
559 Stars
JVM formal verification tool containing a model checker and more. Created by NASA.
222 Stars
Detects likely program invariants and generates JML specs based on those invariants.
151 Stars
Translates JML specifications into SMT-LIB format and passes the proof problems implied by the program to backend solvers. (GPL-2.0-only)
104 Stars
Concolic unit testing engine. Automatically generates unit tests using formal methods.
54 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.
5879 Stars
Functional component library that provides persistent data types and functional control structures.
2235 Stars
Enhances Java 8 Streams.
2105 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.
1612 Stars
Implements numerous basic and advanced programming abstractions that assist composition-oriented development.
1323 Stars
Monad and stream utilities, comprehensions, pattern matching, functional extensions for all JDK collections, future streams, trampolines and much more.
570 Stars
Java 8 annotation processor and framework for deriving algebraic data types constructors, pattern-matching and morphisms. (GPL-3.0-only)
480 Stars
Collection of stream utilities.
Game Development
Frameworks that support the development of games.
23878 Stars
All-round cross-platform, high-level framework.
4981 Stars
Robust framework that abstracts libraries like OpenGL/CL/AL.
4563 Stars
JavaFX Game Development Framework.
3933 Stars
Game engine for modern 3D development.
1125 Stars
Port of the renowned C++ 2D physics engine.
766 Stars
AWT-based, lightweight 2D game engine.
506 Stars
Beginner-friendly, master-ready framework for rapidly prototyping and building 2D games.
0 Stars
High-level 2D game engine with built-in physics based on Swing.
Geospatial
Libraries for working with geospatial data and algorithms.
5695 Stars
Road-routing engine. Used as a Java library or standalone web service.
1774 Stars
Library that provides tools for geospatial data. (LGPL-2.1-only)
1236 Stars
Map rendering based on OpenStreetMap data. (LGPL-3.0-only)
941 Stars
General-purpose spatial/geospatial library.
418 Stars
GeoHash utilities in Java.
213 Stars
Spatial extension of the H2 database. (LGPL-3.0-only)
100 Stars
Library for developing geospatial applications.
66 Stars
Library for using the GeoHash algorithm.
GUI
Libraries to create modern graphical user interfaces.
2900 Stars
Successor of Swing.
767 Stars
Visual layout tool for JavaFX applications.
136 Stars
Graphical widget toolkit.
High Performance
Everything about high-performance computation, from collections to specific libraries.
17698 Stars
Inter-thread messaging library.
3641 Stars
Concurrency tools currently missing from the JDK.
1866 Stars
Fast and compact type-specific collections.
1014 Stars
Carefully designed extension of the Java Collections Framework with primitive specializations and more.
1001 Stars
Primitive collections.
0 Stars
Data structures and utility methods that are common in high-performance applications.
0 Stars
Collections framework inspired by Smalltalk.
HTTP Clients
Libraries that assist with creating HTTP requests and/or binding responses.
43401 Stars
Typesafe REST client.
9625 Stars
HTTP client binder inspired by Retrofit, JAXRS-2.0, and WebSocket.
6329 Stars
Asynchronous HTTP and WebSocket client library.
4601 Stars
Client-side IPC library that is battle-tested in the cloud.
2655 Stars
Simplified, lightweight HTTP client library.
1489 Stars
A toolset of low-level Java components focused on HTTP and associated protocols.
1397 Stars
Pluggable HTTP transport abstraction with support for java.net.HttpURLConnection, Apache HTTP Client, Android, Google App Engine, XML, Gson, Jackson and Protobuf.
316 Stars
Client-side response routing for Spring's RestTemplate.
264 Stars
HTTP client extensions library.
74 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.
169451 Stars
Provides Java support for lightweight projects with a simple, modern workflow by using extensions from the internal marketplace.
2777 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.
33199 Stars
Multi-format 1D/2D barcode image processing library.
5245 Stars
High-quality thumbnail generation library.
1985 Stars
Collection of plugins that extend the number of supported image file formats.
1659 Stars
JNA wrapper for Tesseract OCR API.
1237 Stars
Simple, efficient and hardware-accelerated image-scaling library implemented in pure Java 2D.
361 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.
4742 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.
2821 Stars
ClassGraph (formerly FastClasspathScanner) is an uber-fast, ultra-lightweight, parallelized classpath scanner and module scanner for Java, Scala, Kotlin and other JVM languages.
2818 Stars
jOOR stands for jOOR Object Oriented Reflection. It is a simple wrapper for the java.lang.reflect package.
1543 Stars
ReflectASM is a very small Java library that provides high performance reflection by using code generation.
608 Stars
Allows dynamic instantiation without default constructor, e.g. constructors which have required arguments, side effects or throw exceptions.
106 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.
6452 Stars
Feature-rich, open source job scheduling library that can be integrated within virtually any Java application.
3818 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.
2522 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.
1351 Stars
Persistent and cluster-friendly scheduler.
620 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.
273 Stars
Lightweight framework to simply define jobs, define triggers and start the scheduler.
136 Stars
Simple library with minimal footprint and straightforward API.
JSON
Libraries for serializing and deserializing JSON to and from Java objects.
25764 Stars
Very fast processor with no additional dependencies and full data binding.
23643 Stars
Serializes objects to JSON and vice versa. Good performance with on-the-fly usage.
9883 Stars
Modern JSON library, less opinionated and uses built-in types like List and Map.
9308 Stars
Similar to GSON, but offers performance gains if you need to instantiate the library more often.
9082 Stars
Extract data from JSON using XPATH-like syntax.
3196 Stars
JSON parsing and serializing library based on Jackson's streaming API. Outperforms GSON & Jackson's library.
1600 Stars
JSON to JSON transformation tool.
1519 Stars
Fast and flexible library with iterator and lazy parsing API.
1027 Stars
JSON library with advanced compile time databinding.
463 Stars
High-performance JSON parser, 2x faster than Jackson.
402 Stars
Set of Jackson modules for Java 8 datatypes and features.
336 Stars
Convert Java to JSON. Convert JSON to Java. Pretty print JSON. Java JSON serializer.
296 Stars
Streaming JsonPath processor dedicated to processing big and complicated JSON data.
258 Stars
Open-source Jackson module to support JSON serialization and deserialization of JavaMoney data types.
218 Stars
Powerful and easy-to-use Java-to-JSON conversion library.
205 Stars
Binding layer between classes and JSON documents similar to JAXB.
70 Stars
Reflection-free Json binding via source code generation with Jackson-like annotations.
JVM and JDK
Current implementations of the JVM/JDK.
20742 Stars
Polyglot embeddable JVM. (GPL-2.0-only WITH Classpath-exception-2.0)
20714 Stars
Open JDK community home. (GPL-2.0-only WITH Classpath-exception-2.0)
4253 Stars
Downstream version of OpenJDK optimized for online e-commerce, financial, logistics applications.
3397 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.
3146 Stars
Community-driven OpenJDK builds, including both HotSpot and OpenJ9.
2118 Stars
No-cost, multiplatform, production-ready distribution of OpenJDK by Amazon. (GPL-2.0-only WITH Classpath-exception-2.0)
1755 Stars
VM with non-blocking, concurrent GC for iOS. (GPL-2.0-only WITH Classpath-exception-2.0)
1225 Stars
JVM with JIT, AOT modes and iOS port.
527 Stars
SAP's no-cost, rigorously tested and JCK-verified OpenJDK friendly fork. (GPL-2.0-only WITH Classpath-exception-2.0)
352 Stars
Built from OpenJDK, thoroughly tested and passed the JCK. (GPL-2.0-only WITH Classpath-exception-2.0)
271 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.
20357 Stars
Analyzes and visualizes log files. Some features require payment.
14406 Stars
Tool for managing log files.
7622 Stars
Open-source aggregator suited for extended role and permission management. (GPL-3.0-only)
3446 Stars
Complete rewrite with a powerful plugin and configuration architecture.
3089 Stars
Robust logging library with interesting configuration options via Groovy.
2396 Stars
Abstraction layer/simple logging facade.
2134 Stars
Enables logging for all JDBC transactions without changes to the code.
1905 Stars
Extensible, open-source library for HTTP request and response logging.
733 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.
55 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.
24702 Stars
Fast, reliable, large-scale data processing engine.
13914 Stars
Distributed and multi-threaded deep learning library.
11747 Stars
Analytics engine for statistics over big data.
6155 Stars
Statistical Machine Intelligence and Learning Engine provides a set of machine learning algorithms and a visualization library.
4405 Stars
High-level and engine-agnostic framework for deep learning.
2869 Stars
CLI tool to transpile models into native code.
2161 Stars
Scalable algorithms focused on collaborative filtering, clustering and classification.
1782 Stars
Framework for building real-time, large-scale machine learning applications. Includes end-to-end applications for collaborative filtering, classification, regression, and clustering.
1537 Stars
Cloud native streaming and complex event processing engine.
1311 Stars
Provides tools for classification, regression, clustering, model development and interfaces with other libraries such as scikit-learn, pytorch and TensorFlow.
1084 Stars
Provides several algorithms and pre-trained models for natural language processing.
792 Stars
Algorithms for pre-processing, classification, regression, and clustering with support for multi-threaded execution. (GPL-3.0-only)
473 Stars
High-performance mathematics, linear algebra and optimisation needed for data science, machine learning and scientific computing.
184 Stars
Collection of algorithms for data mining tasks ranging from pre-processing to visualization. (GPL-3.0-only)
64 Stars
Seamlessly integrate with remote deep learning and language models programmatically.
Messaging
Tools that help send messages between clients to ensure protocol independency.
29797 Stars
High-throughput distributed messaging system.
24744 Stars
Simple publish/subscribe event bus.
21671 Stars
Fast, reliable, and scalable distributed messaging platform.
14523 Stars
Distributed pub/sub-messaging system.
5783 Stars
Glues together different transport APIs via Enterprise Integration Patterns.
2398 Stars
Cross-platform XMPP client library.
2389 Stars
Implementation of ZeroMQ.
2348 Stars
Message broker that implements JMS and converts synchronous to asynchronous communication.
1267 Stars
RabbitMQ client.
954 Stars
Provides a RESTful API on top of Kafka.
823 Stars
Fast and reliable message broker built on top of Kafka.
587 Stars
NATS client.
128 Stars
Apache Qpid makes messaging tools that speak AMQP and support many languages and platforms.
42 Stars
Simple, lightweight, and performant dispatch library for decoupling messages (requests and events) and message handlers.
0 Stars
Efficient, reliable, unicast and multicast message transport.
Microservice
Tools for creating and managing microservices.
31090 Stars
Dynamic service discovery, configuration and service management platform for building cloud native applications.
22651 Stars
Flow control component enabling reliability, resilience and monitoring for microservices.
14286 Stars
Kubernetes stack tailored for the HotSpot and Graal VM.
12518 Stars
REST-based service registry for resilient load balancing and failover.
6196 Stars
Modern full-stack framework with focus on modularity, minimal memory footprint and startup time.
4891 Stars
Asynchronous RPC/REST client/server library built on top of Java 8, Netty, HTTP/2, Thrift and gRPC.
4800 Stars
Java libraries for using OpenAI's GPT-3 API.
4445 Stars
Wrapping of the Discord REST API and its WebSocket events.
3608 Stars
Two-style approach for writing microservices: Functional-reactive and as an implementation of MicroProfile.
3489 Stars
Client provides access to the full Kubernetes & OpenShift REST APIs via a fluent DSL.
1642 Stars
Libraries for writing composable microservices.
941 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.
91161 Stars
Implementation and explanation of the most common design patterns.
22308 Stars
No-nonsense implementation of FizzBuzz made by serious businessmen for serious business purposes. (No explicit license)
16771 Stars
Modern Java - A Guide to Java 8
Popular Java 8 guide.
11242 Stars
Tool for working with messy data: cleaning, transforming, extending it with web services and linking it to databases.
6007 Stars
Java-to-Objective-C translator for porting Android libraries to iOS.
5306 Stars
Browser extension which allows to navigate through code on GitHub more efficiently.
2613 Stars
Library for the Svix API to send webhooks and verify signatures.
2472 Stars
In-memory file system.
2269 Stars
Wrapper around AWS' API.
2082 Stars
High performance HTTP proxy atop Netty's event-based networking library.
1747 Stars
Ultra-fast, SQL-like queries on Java collections.
1582 Stars
Analogue of Gradle Wrapper for Maven, allows building projects without installing maven.
1470 Stars
Source transpiler to TypeScript/JavaScript.
1410 Stars
Feature Flags for Java.
1245 Stars
Mailing with a clean and fluent API.
1201 Stars
Framework for building chatbots. (GPL-3.0-only)
1132 Stars
Static website generator.
981 Stars
Implementation of the Feature Toggles pattern.
900 Stars
Extensions for Maven 3.3.1+ that allows writing the POM model in dialects other than XML.
663 Stars
Basic currency and money classes and algorithms not provided by the JDK.
629 Stars
Tools for resolving generic types.
498 Stars
Simple wrapper for the org.w3c.dom package, to allow for fluent XML document creation and manipulation with an API inspired by jQuery.
478 Stars
Open-source, reverse-proxy framework.
401 Stars
Obfuscation via renaming and shrinking.
400 Stars
Framework for fragment-based message processing. (Apache-2.0 OR LGPL-3.0-or-later)
381 Stars
Detect uses of legacy Java APIs.
246 Stars
JCuda offers Java bindings for CUDA and CUDA-related libraries.
166 Stars
Lightweight, small and customizable FTP server.
73 Stars
Processes XML by using annotations or XPath within code.
38 Stars
Source code obfuscator.
24 Stars
RR4J is a tool that records java bytecode execution and later allows developers to replay locally.
0 Stars
Small utility library for using handlers and commands with pipelines.
Mobile Development
Tools for creating or managing mobile applications.
1755 Stars
Cross-platform solution for writing native mobile apps. (GPL-2.0-only WITH Classpath-exception-2.0)
580 Stars
Open-source, cross-platform engine to develop native mobile (iOS, Android, etc.) apps.
Monitoring
Tools that monitor applications in production.
17164 Stars
Distributed tracing system which gathers timing data needed to troubleshoot latency problems in microservice architectures.
13559 Stars
Open-source APM tool.
7843 Stars
Expose metrics via JMX or HTTP and send them to a database.
5724 Stars
Dynamic and observable thread pool framework.
2998 Stars
Performance monitoring and profiling.
2216 Stars
Provides a multi-dimensional data model, DSL, autonomous server nodes and much more.
1706 Stars
Open-source performance monitoring and transaction tracing for JVM apps.
1701 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.
1266 Stars
Open-source Java APM.
1201 Stars
Integration with [Sentry](https://github.com/getsentry/sentry), an application error tracking and performance analysis platform.
824 Stars
JMX over REST.
627 Stars
Modern monitoring & analytics.
572 Stars
Combines the power of AOP with monitoring and/or logging tools.
539 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.
491 Stars
Jaeger client.
161 Stars
Remote developer console from the browser for Java 8 via bytecode injection.
154 Stars
Lightweight platform monitoring tool for Java VMs.
53 Stars
Out of the box monitoring of Failsafe Circuit Breaker in Spring-Boot environment.
22 Stars
Performance monitor with distributing transaction tracing for JVM apps.
0 Stars
Real-time monitoring system with custom-monitor and agentless.
Native
For working with platform-specific native libraries.
8663 Stars
Work with native libraries without writing JNI. Also provides interfaces to common system libraries.
4564 Stars
Provides efficient and easy access to native C++.
1278 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).
475 Stars
Converts bytecode to OpenCL which allows execution on GPUs.
Natural Language Processing
Libraries that specialize in processing text.
9841 Stars
Provides a set of fundamental tools for tasks like tagging, named entity recognition, and sentiment analysis. (GPL-3.0-or-later)
475 Stars
Provides common annotators for plain text input. (Research and Academic Use License)
198 Stars
Collection of reusable NLP tools for linguistic pre-processing, machine learning, lexical resources, etc.
Networking
Libraries for building network servers.
40868 Stars
High-performance RPC framework.
33951 Stars
Framework for building high-performance network applications.
11670 Stars
RPC framework based on protobuf and HTTP/2.
3630 Stars
Web server providing both blocking and non-blocking APIs based on NIO. Used as a network layer in WildFly. (LGPL-2.1-only)
2543 Stars
Programmatically use SSH, SCP or SFTP.
1829 Stars
Provides a clean and simple API for efficient TCP and UDP client/server network communication using NIO and Kryo.
949 Stars
Framework built on Netty with APIs tailored to specific protocols and support for multiple programming paradigms.
910 Stars
Abstract, event-driven async I/O API for network operations over TCP/IP and UDP/IP via Java NIO.
598 Stars
Integrates standard Java web-related APIs with Quasar fibers and actors.
242 Stars
Easy-to-use, annotation-based library for creating Thrift clients and serializable types.
199 Stars
Implements a ByteChannel interface over SSLEngine, enabling easy-to-use (socket-like) TLS.
154 Stars
High throughput data ingestion logger to Fluentd and Fluent Bit.
32 Stars
Represent, parse and encode URNs, as in RFC 2141. (GPL-3.0-only)
17 Stars
Client for server-sent events (SSE).
0 Stars
NIO framework. Used as a network layer in Glassfish.
ORM
APIs that handle the persistence of objects.
20019 Stars
Couples objects with stored procedures or SQL statements.
6126 Stars
Robust and widely used, with an active community. (LGPL-2.1-only)
1489 Stars
Provides simple and fast data access.
1256 Stars
ActiveRecord ORM for rapid development and convention over configuration.
466 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.
441 Stars
Simple database and CSV mapper.
411 Stars
Language-natural persistence layer.
323 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.
213 Stars
Supports a number of persistence standards: JPA, JAXB, JCA and SDO.
PaaS
Java platform as a service.
Tools to help with PDF files.
3794 Stars
Open-source iText fork. (LGPL-3.0-only & MPL-2.0)
2789 Stars
Toolbox for creating and manipulating PDFs.
2072 Stars
XML/XHTML and CSS 2.1 renderer. (LGPL-2.1-or-later)
1991 Stars
Properly supports modern PDF standards based on flyingsaucer and Apache PDFBox.
1906 Stars
Extracts tables from PDF files.
1639 Stars
Creates PDF files programmatically.
477 Stars
Report engine for creating PDF and other formats (DOCX, XLSX, HTML, etc) using Eclipse-based visual editor.
249 Stars
Abstraction layer to JasperReports. (LGPL-3.0-only)
224 Stars
Simplifies JasperReports. (LGPL-3.0-only)
194 Stars
Creates PDFs from XSL-FO.
0 Stars
Complex reporting engine. (LGPL-3.0-only)
Performance analysis
Tools for performance analysis, profiling and benchmarking.
3146 Stars
Analyze the JIT compiler optimisations made by the HotSpot JVM.
2351 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)
1252 Stars
Low-overhead, bias-free sampling profiler.
686 Stars
Logs and records platform JVM stalls.
460 Stars
Utilities for latency measurement and reporting.
Apache Commons
Reusable, open source Java software.
2782 Stars
Provides extra functionality for classes in java.lang.
1028 Stars
Collection of I/O utilities.
703 Stars
Extends or augments the Java Collections Framework.
605 Stars
Lightweight, self-contained mathematics and statistics components.
530 Stars
Generic object pooling component.
466 Stars
General encoding/decoding algorithms, e.g. phonetic, base64 or URL.
450 Stars
Image library.
389 Stars
Component for reading and writing comma separated value files.
381 Stars
JDBC helper library.
366 Stars
Command-line arguments parser.
353 Stars
Defines an API for working with tar, zip and bzip2 files.
349 Stars
Database connection pooling services.
290 Stars
Easy-to-use wrappers around the Java reflection and introspection APIs.
266 Stars
Collection of network utilities and protocol implementations.
256 Stars
Byte Code Engineering Library - analyze, create, and manipulate Java class files.
245 Stars
File upload capability for your servlets and web applications.
241 Stars
Virtual File System component for treating files, FTP, SMB, ZIP and such like as a single logical file system.
214 Stars
Framework to define validators and validation rules in an xml file.
208 Stars
Reading of configuration/preferences files in various formats.
208 Stars
Expression language which extends the Expression Language of the JSTL.
165 Stars
Library for sending e-mail from Java.
153 Stars
Wrapper around a variety of logging API implementations.
150 Stars
API for dealing with external process execution and environment management in Java.
98 Stars
Java Caching System.
96 Stars
Alternative invocation mechanism for unix-daemon-like java code.
83 Stars
Object-graph navigation language.
76 Stars
Chain of Responsibility pattern implementation.
55 Stars
XML-to-Java-object mapping utility.
55 Stars
Commons Rng provides implementations of pseudo-random numbers generators.
55 Stars
Implementation of the State Chart XML specification aimed at creating and maintaining a Java SCXML engine.
47 Stars
Common implementation of RDF 1.1 that could be implemented by systems on the JVM.
33 Stars
Utilities for manipulating Java Beans using the XPath syntax.
32 Stars
General purpose graph APIs and algorithms.
25 Stars
Library for creating dynamic proxies.
24 Stars
Bean Scripting Framework - interface to scripting languages, including JSR-223.
23 Stars
Function that can be manipulated as an object, or an object representing a single, generic function.
21 Stars
Provides an easy way to enhance (weave) compiled bytecode.
17 Stars
XML based scripting and processing engine.
14 Stars
Java Compiler Interface.
Other
Other kinds of platforms
3639 Stars
Fast, lightweight and productive microservices framework with built-in [security](https://github.com/networknt/light-oauth2/).
1337 Stars
High-level framework for developing enterprise applications with a rich web interface, based on Spring, EclipseLink and Vaadin.
252 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.
892 Stars
Provides a unified API to Apache Commons Exec and ProcessBuilder.
130 Stars
Stops processes started from Java or the system processes via PID.
34 Stars
Convenient API around Apache Commons Exec.
Reactive libraries
Libraries for developing reactive applications.
48057 Stars
Allows for composing asynchronous and event-based programs using observable sequences.
14448 Stars
Polyglot event-driven application framework.
13132 Stars
Toolkit and runtime for building concurrent, distributed, fault-tolerant and event-driven applications.
5061 Stars
Library for building reactive fast-data applications.
4835 Stars
Provides a standard for asynchronous stream processing with non-blocking backpressure.
REST Frameworks
Frameworks specifically for creating RESTful services.
9653 Stars
Sinatra inspired framework.
8528 Stars
Opinionated framework for setting up modern web applications with Jetty, Jackson, Jersey and Metrics.
3398 Stars
Automates the generation of API documentation using Spring Boot projects.
2517 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.
1628 Stars
Simple, secure and extremely fast framework consisting of an embedded HTTP server, GUI components and dependency injection.
1114 Stars
Fully certified and portable implementation of the JAX-RS specification.
1006 Stars
Opinionated framework for JSON- or GraphQL-APIs based on a JPA data model.
936 Stars
Thin wrapper on the JBoss Netty HTTP stack that provides scaling and performance.
934 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.
701 Stars
JAX-RS reference implementation.
656 Stars
Pioneering framework with powerful routing and filtering capabilities, and a unified client and server API.
287 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.
3611 Stars
Includes a data-frame, an embedded column store, and hundreds of methods to transform, summarize, or filter data.
2662 Stars
Graph library that provides mathematical graph-theory objects and algorithms.
1534 Stars
Light-weight library for plotting data. Many customizable chart types are available.
1263 Stars
2D chart library for Swing, JavaFX and server-side applications. (LGPL-2.1-only)
676 Stars
Library for visualizing (mainly Swing) and interacting with node-edge graphs.
604 Stars
Facilitates processing biological data by providing algorithms, file format parsers, sequencing and 3D visualization commonly used in bioinformatics.
527 Stars
Scientific charting library with focus on performance optimised real-time data visualisation at 25 Hz update rates for large data sets.
408 Stars
Library for modeling and analyzing dynamic graphs.
240 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.
140 Stars
Library for creating, manipulating and solving Boolean and Pseudo-Boolean formulas.
128 Stars
Modular, light and easy graph framework for theoretic algorithms.
109 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)
76 Stars
Library for geophysical scientific computation, visualization and digital signal analysis.
Search
Engines that index documents for search and analysis.
72211 Stars
Distributed, multitenant-capable, full-text search engine with a RESTful web interface and schema-free JSON documents.
2910 Stars
High-performance, full-featured, cross-platform, text search engine library.
1347 Stars
Enterprise search engine optimized for high-volume traffic.
55 Stars
Simple and light full text indexing and searching library.
Security
Libraries that handle security, authentication, authorization or session management.
26326 Stars
Integrated SSO and IDM for browser apps and RESTful web services.
12628 Stars
Multiplatform, transparent, client-side encryption of files in the cloud. (GPL-3.0-only)
10562 Stars
JSON web token for Java and Android.
4366 Stars
Performs authentication, authorization, cryptography and session management.
2618 Stars
System for distributing and managing secrets.
2463 Stars
Security engine.
2417 Stars
All-purpose cryptographic library and JCA provider offering a wide range of functions, from basic helpers to PGP/SMIME operations.
1906 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.
1175 Stars
Fine-grained authorization for applications with support for RBAC, ABAC, and ReBAC.
808 Stars
Access management solution that includes authentication, SSO, authorization, federation, entitlements and web services security.
524 Stars
High-level SSL context builder for configuring HTTP clients with SSL/TLS.
370 Stars
User-friendly cryptographic library that supports Argon2, Bcrypt, Scrypt, PBKDF2 and various other cryptographic hash functions.
295 Stars
Advanced password strength estimation.
291 Stars
Enforce password policy by validating candidate passwords against a configurable rule set.
214 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.
212 Stars
One-time password generator library according to RFC 4226 (HOTP) and RFC 6238 (TOTP).
209 Stars
Binding for the Networking and Cryptography (NaCl) library.
200 Stars
JSON Web Key Set parser.
105 Stars
Provides permission-based authorization services.
46 Stars
Fluent Builder API for JCA and JSSE classes and especially X.509 certificates.
11 Stars
Easily create and parse JSON Web Tokens and create customized JWT validators using a fluent API.
8 Stars
Detects publicly disclosed vulnerabilities contained within a project's dependencies.
0 Stars
Provides a simple and misuse-proof API for common cryptographic tasks.
Serialization
Libraries that handle serialization with high efficiency.
24009 Stars
Memory-efficient serialization library that can access serialized data without unpacking and parsing it.
6282 Stars
Fast and efficient object graph serialization framework.
1593 Stars
JDK-compatible, high-performance object graph serialization.
1432 Stars
Efficient binary serialization format.
15 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.
7771 Stars
Robust, all-round server for Servlet and JSP.
7055 Stars
Tiny, easily embeddable HTTP server.
3907 Stars
Provides a Web server and javax.servlet container, plus support for HTTP/2, WebSocket, OSGi, JMX, JNDI, JAAS and many other integrations.
3094 Stars
Formerly known as JBoss and developed by Red Hat with extensive Java EE support. (LGPL-2.1-only)
463 Stars
Tomcat plus Java EE.
Template Engine
Tools that substitute expressions in a template.
2864 Stars
Aims to be a substitute for JSP and works for XML files.
1488 Stars
Logicless and semantic Mustache templates.
1131 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.
1018 Stars
Library to generate text output (HTML web pages, e-mails, configuration files, source code, etc.) based on templates and changing data.
971 Stars
Template engine for generating source code, web pages, emails, or any other formatted text output.
920 Stars
Compiles to classes, and uses an easy syntax, several features to make development easier and provides fast execution and a small footprint.
761 Stars
Optimized, memory efficient and speedy template engine producing statically typed, plain objects.
705 Stars
Implementation of Pug (formerly known as Jade).
302 Stars
Modular, configurable and fully tested template engine.
288 Stars
Typesafe Mustache templating engine.
60 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.
2738 Stars
Provides a way to describe features in a plain language which customers can understand.
732 Stars
Automated Acceptance testing and reporting library that works with Cucumber, JBehave and JUnit to make it easier to write high quality executable specifications.
445 Stars
Provides a fluent API which allows for simpler composition.
255 Stars
Aims to provide a fluent API to write tests in long and descriptive sentences that read like plain English.
159 Stars
Extensively configurable framework that describes stories.
112 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.
4840 Stars
Port of Ruby's fake data generator.
992 Stars
Automates data setup in unit tests by generating fully-populated, reproducible objects. Includes JUnit 5 extension.
739 Stars
Fake data generator.
531 Stars
Another fake data generator.
445 Stars
Generates fake objects from a template.
173 Stars
JUnit test runner and plugins for running JUnit tests with pseudo-randomness.
118 Stars
Sets up beans from YAML fixtures.
Frameworks
Provide environments to run tests for a specific use case.
8671 Stars
Functional testing and performance measurements.
6600 Stars
Load testing tool designed for ease of use, maintainability and high performance.
6564 Stars
Common testing framework.
3360 Stars
Test library for specifying and asserting architecture rules.
1732 Stars
Fast mutation-testing framework for evaluating fault-detection abilities of existing JUnit or TestNG test suites.
1097 Stars
Consumer-driven contract testing.
587 Stars
Engine for property-based testing built on JUnit 5.
465 Stars
Integration testing framework that focuses on both client- and server-side messaging.
382 Stars
Integration and functional testing platform for Java EE containers.
Matchers
Libraries that provide custom matchers.
2742 Stars
Google's fluent assertion and proposition framework.
2684 Stars
Fluent assertions that improve readability.
2122 Stars
Matchers that can be combined to create flexible expressions of intent.
1028 Stars
Simplifies testing JSON strings.
917 Stars
Library that simplifies JSON comparison in tests.
304 Stars
Simplifies testing for XML output.
Miscellaneous
Other stuff related to testing.
8176 Stars
Provides throwaway instances of common databases, Selenium web browsers, or anything else that can run in a Docker container.
392 Stars
Captures log entries for unit testing purposes.
246 Stars
TestNG-like data provider/runner for JUnit.
240 Stars
Reports whether instances of a given class are immutable.
71 Stars
Tests if a request/response matches a given RAML definition.
53 Stars
Automatically performs tests on basic POJO methods. (LGPL-3.0-only)
30 Stars
Captures console output for unit testing purposes.
14 Stars
Captures log entries and provides assertions for unit and integration testing.
Mocking
Tools which mock collaborators to help testing single, isolated units.
15106 Stars
Mocking framework that lets you write tests with a clean and simple API.
6689 Stars
Stubs and mocks web services.
4696 Stars
Allows mocking of systems integrated with HTTPS.
4397 Stars
Concise web services for stubs and mocks.
4182 Stars
Mocks static methods, constructors, final classes and methods, private methods, and removal of static initializers.
463 Stars
Integration testing, API mocking and faking, and code coverage.
Utility
Libraries which provide general utility functions.
50637 Stars
Collections, caching, primitives support, concurrency libraries, common annotations, string processing, I/O, and more.
36113 Stars
Allows to troubleshoot production issues for applications without modifying code or restarting servers.
6068 Stars
Cross-platform for visualizing and manipulating large graph networks. (GPL-3.0-only)
2628 Stars
Library that helps with constructing difficult regular expressions.
2462 Stars
Rate limiting library based on token-bucket algorithm.
1767 Stars
Bulk data loader that helps data transfer between various databases, storages, file formats, and cloud services.
1343 Stars
Utilities for text or data comparison and patching.
1320 Stars
Java/JavaFX tool capable of powerful ETL and data visualization.
1166 Stars
Provides simple APIs to access any Amazon S3-compatible object storage server.
1058 Stars
Provides an ontology editor and a framework to build knowledge-based systems.
936 Stars
Provides a shell into a JVM that's running CRaSH. Used by Spring Boot and others. (LGPL-2.1-or-later)
748 Stars
Collection of object-oriented primitives.
537 Stars
Port of Underscore.js functions.
42 Stars
Generates postman collection, environment and integration tests from java code.
42 Stars
Lightweight, pure Java library implementing the Git version control system.
28 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.
6286 Stars
Java Version Manager inspired by RVM and rbenv. Supports UNIX-based platforms.
6097 Stars
Java Version Manager inspired by rbenv. Can configure globally or per project. Tested on Debian and macOS.
3126 Stars
Java Version Manager inspired by nvm. Supports macOS, Linux and Windows.
Web Crawling
Libraries that analyze the content of websites.
11529 Stars
Scalable crawler with downloading, url management, content extraction and persistent.
11101 Stars
Scrapes, parses, manipulates and cleans HTML.
4583 Stars
Simple and lightweight web crawler.
3002 Stars
Highly extensible, highly scalable web crawler for production environments.
0 Stars
SDK for building low-latency and scalable web crawlers.
Web Frameworks
Frameworks that handle the communication between the layers of a web application.
12557 Stars
Built on Akka, it provides predictable and minimal resource consumption (CPU, memory, threads) for highly-scalable applications in Java and Scala.
7815 Stars
Microframework for web applications.
5860 Stars
Lightweight, modular framework that aims to be elegant and simple.
1942 Stars
Set of libraries that facilitate fast, efficient, evolvable and well-tested HTTP applications.
1904 Stars
Full-stack web framework.
1836 Stars
JSF framework with both free and commercial/support versions and frontend components.
1786 Stars
Event-driven framework that uses standard web components. Server-side architecture with Ajax on the client side.
1730 Stars
Scalable, fast and modular micro-framework that offers multiple programming models.
1414 Stars
Minimally opinionated framework for runnable apps.
941 Stars
Lightweight asynchronous framework built from the ground up for developing high-performance web applications.
815 Stars
Opinionated web framework which is built around the concepts of True Object-Oriented Programming and immutability.
785 Stars
Small, highly modularized, Sinatra-like framework.
753 Stars
Component-based web application framework similar to Tapestry, with a stateful GUI.
295 Stars
Asynchronous framework for rapid development of high-performance web application.
123 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.