微信开发 Java SDK ，支持包括微信支付，开放平台，小程序，企业微信，视频号，公众号等的后端开发

OpenAPI Generator allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec (v2, v3)

card.io provides fast, easy credit card scanning in mobile apps

iText for Java represents the next level of SDKs for developers that want to take advantage of the benefits PDF can bring. Equipped with a better document engine, high and low-level programming capabilities and the ability to create, edit and enhance PDF documents, iText can be a boon to nearly every workflow.

The Android SDK for Parse Platform

Chat SDK Android - Open Source Mobile Messenger

Alibaba Cloud SDK for Java

Eclipse Milo™ - an open source implementation of OPC UA (IEC 62541).

Alipay Easy SDK for multi-language(java、c#、php、ts etc.) allows you to enjoy a minimalist programming experience and quickly access the various high-frequency capabilities of the Alipay Open Platform.

App 内部更新 提供12种更新的样式 支持Android全系统版本 支持自定义UI 断点续传

MinIO Client SDK for Java

JAVA安全SDK及编码规范

Official Android Tracking Library for Mixpanel Analytics

微信支付 APIv3 的官方 Java Library

The Alexa Skills Kit SDK for Java helps you get a skill up and running quickly, letting you focus on skill logic instead of boilerplate code.

The NASA WorldWind Java SDK (WWJ) is for building cross-platform 3D geospatial desktop applications in Java.

微信tinker补丁管理，后端代码+客户端sdk

Countly Product Analytics Android SDK

Evolve the Android notification experience of existing apps, with community-driven plug-ins.

微信支付 APIv3 Apache HttpClient装饰器（decorator）