Class QueryEngine

All Implemented Interfaces:

public class QueryEngine
extends java.lang.Object
implements QueryExecution

An execution of a query. The query is not modified so can be reused. A new QueryEngine object should be created because the internal state after (and during) execution of a query is not defined. This implementation executes the triple pattern generation on a one thread, executes the constraint filters on another, and leaving the application thread just to return results.

See Also:
Query, QueryResults

Constructor Summary
QueryEngine(Query q)
Method Summary
 void abort()
          Stop in mid execution.
 void close()
          Normal end of use of this execution
 QueryResults exec()
          Do it!
 void init()
          Initialise a query execution.
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail


public QueryEngine(Query q)
Method Detail


public void init()
Initialise a query execution. May be called before exec. If it has not be called, the query engine will initialise itself during the exec() method.
Specified by:
init in interface QueryExecution


public QueryResults exec()
Description copied from interface: QueryExecution
Do it!
Specified by:
exec in interface QueryExecution


public void abort()
Description copied from interface: QueryExecution
Stop in mid execution. No guarantee that the concrete implementation actual will stop or that it wil do so immediately.
Specified by:
abort in interface QueryExecution


public void close()
Normal end of use of this execution
Specified by:
close in interface QueryExecution

Copyright 2001 Hewlett-Packard. All Rights Reserved.