用Java也能调用的C++库
The missing Java distribution of native C++ libraries
https://github.com/bytedeco/javacpp-presets
高性能文本去重复
Diff Match Patch is a high-performance library in multiple languages that manipulates plain text.
https://github.com/google/diff-match-patch
光学字符识别引擎
https://github.com/tesseract-ocr/tesseract
日出日落
Library for computing the sunrise/sunset from GPS coordinates and a date, in Java.
https://github.com/mikereedell/sunrisesunsetlib-java
行政区划
https://github.com/modood/Administrative-divisions-of-China
Q.E.D.