Using App Engine Datastore Low Level API with Java

问题

How to find the total number of entries in an entity type in App Engine Datastore using Low Level API?

I there a function or filter to query for this purpose?

I am using Java to implement this.

回答1:

App Engine has an API for getting datastore statistics programmatically:

DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
Entity globalStat = datastore.prepare(new Query("__Stat_Total__")).asSingleEntity();
Long totalBytes = (Long) globalStat.getProperty("bytes");
Long totalEntities = (Long) globalStat.getProperty("count")

See the documentation: https://cloud.google.com/appengine/docs/java/datastore/stats

You can get entities of a kind using __Stat_Kind__

来源：https://stackoverflow.com/questions/27573330/using-app-engine-datastore-low-level-api-with-java