English ▼
Skip to page content Skip to main navigation
e.g. "templates" or "datastore"

# Prospective Search (Java)

Prospective search allows an application to register a large set of queries that are simultaneously matched against a stream of input documents. For every document presented, prospective search returns the IDs of all registered queries matching the document. Prospective search is particularly useful when building applications that process streaming data sources such as those that provide notification, monitoring, or filtering services.

#### Experimental!

Prospective Search is an experimental, innovative, and rapidly changing new feature for App Engine. Unfortunately, being on the bleeding edge means that we may make backwards-incompatible changes to Prospective Search. We will inform the community when this feature is no longer experimental.

The following documents describe the Java API for the prospective search service.

- Overview
- Javadoc Reference