Google App Engine 地理散列 [英] Google App Engine Geohashing
问题描述
我正在使用 GWT 和 App Engine 编写网络应用程序.我的应用程序需要根据纬度、经度发布和查询项目.
I am writing a web application using GWT and App Engine. My application will need to post and query items based on their latitude, longitude.
由于 google 的分布式数据库设计,您不能简单地查询一组不等式.相反,他们建议进行地理哈希.此页面描述了该方法.
As a result of google's distributed database design you can't simple query a set of inequalities. Instead they suggest doing geohashing. The method is described on this page.
http://code.google.com/appengine/articles/geosearch.html
本质上,您预先计算了一个边界框,以便您可以查询已用该边界框标记的项目.
Essentially you pre compute a bounding box so that you can query items that have been tagged with that bounding box.
流程中有一部分我不明白.切片"属性是什么意思?
There is one part of the process that I don't understand. What does the "slice" attribute mean?
感谢您的帮助!
推荐答案
有关 Geomodel 的完整 Java 移植,请参阅 http://code.google.com/p/javageomodel/.
For a complete java portage of Geomodel, please see http://code.google.com/p/javageomodel/.
有一个演示类向您解释如何使用它.
There is a demo class to explain you how to use it.
这篇关于Google App Engine 地理散列的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!