[ 源代码： spatial4j-0.4 ]
软件包：libspatial4j-0.4-java（0.4.1-6）
spatial/geospatial Java library
Spatial4j is a general purpose spatial / geospatial Java library. It's core capabilities are 3-fold: to provide common geospatially-aware shapes, to provide distance calculations and other math, and to read and write the shapes to strings.