org.apache.geode.cache.query

Interface CqQuery

public interface CqQuery

Interface for continuous query. This provides methods for managing a CQ once it is created through the QueryService. The methods allow you to retrieve CQ related information, operate on CQ like execute, stop, close and get the state of the CQ.

Since:

GemFire 5.5

Method Summary

Modifier and Type	Method and Description
void	close() Close the CQ and stop execution.
void	execute() Start executing the CQ or if this CQ is stopped earlier, resumes execution of the CQ.
<E> CqResults<E>	executeWithInitialResults() Starts executing the CQ or, if the CQ is in a stopped state, resumes execution.
CqAttributes	getCqAttributes() Get CqAttributes for this CQ.
CqAttributesMutator	getCqAttributesMutator() Get CqAttributesMutator for this CQ.
String	getName() Get the name of the CQ.
Query	getQuery() Get the query object generated for this CQs query.
String	getQueryString() Get the original query string that was specified with CQ.
CqState	getState() Get the state of the CQ in CqState object form.
CqStatistics	getStatistics() Get statistics information for this CQ.
boolean	isClosed() This allows to check if the CQ is closed.
boolean	isDurable() This allows to check if the CQ is durable.
boolean	isRunning() This allows to check if the CQ is in running or active.
boolean	isStopped() This allows to check if the CQ is in stopped.
void	stop() Stops this CqQuery without releasing resources.

Method Detail

getQueryString

String getQueryString()

Get the original query string that was specified with CQ.

Returns:

String the query string associated with CQ.

getQuery

Query getQuery()

Get the query object generated for this CQs query.

Returns:

Query query object for the query string.

getName

String getName()

Get the name of the CQ.

Returns:

the name of the CQ.

getStatistics

CqStatistics getStatistics()

Get statistics information for this CQ.

Returns:

CqStatistics CQ statistics object.

getCqAttributes

CqAttributes getCqAttributes()

Get CqAttributes for this CQ.

Returns:

CqAttributes cqAttribute set with this CqQuery.

See Also:

CqAttributes

getCqAttributesMutator

CqAttributesMutator getCqAttributesMutator()

Get CqAttributesMutator for this CQ.

Returns:

CqAttributesMutator.

See Also:

CqAttributesMutator

executeWithInitialResults

<E> CqResults<E> executeWithInitialResults()
                                    throws CqClosedException,
                                           RegionNotFoundException,
                                           CqException

Starts executing the CQ or, if the CQ is in a stopped state, resumes execution. Gets the current resultset for the CQ query. The CQ is executed on the primary server, and then redundant servers as needed. If execution fails on all servers, a CqException is thrown. If the query is complex and the data set is large, this execution may take a long time, which may cause a socket read timeout in the client. To allow adequate time, you may need to set a longer pool read-timeout in the client.

Type Parameters:

E - the type contained in the returned CqResults

Returns:

SelectResults resultset obtained by executing the query.

Throws:

CqClosedException - if this CqQuery is closed.

RegionNotFoundException - if the specified region in the query string is not found.

IllegalStateException - if the CqQuery is in the RUNNING state already.

CqException - if failed to execute and get initial results.

execute

void execute()
      throws CqClosedException,
             RegionNotFoundException,
             CqException

Start executing the CQ or if this CQ is stopped earlier, resumes execution of the CQ. The CQ is executed on primary and redundant servers, if CQ execution fails on all the server then a CqException is thrown.

Throws:

CqClosedException - if this CqQuery is closed.

RegionNotFoundException - if the specified region in the query string is not found.

IllegalStateException - if the CqQuery is in the RUNNING state already.

CqException - if failed to execute.

stop

void stop()
   throws CqClosedException,
          CqException

Stops this CqQuery without releasing resources. Puts the CqQuery into the STOPPED state. Can be resumed by calling execute or executeWithInitialResults.

Throws:

IllegalStateException - if the CqQuery is in the STOPPED state already.

CqClosedException - if the CQ is CLOSED.

CqException - if failed to stop.

getState

CqState getState()

Get the state of the CQ in CqState object form. CqState supports methods like isClosed(), isRunning(), isStopped().

Returns:

CqState state object of the CQ.

See Also:

CqState

close

void close()
    throws CqClosedException,
           CqException

Close the CQ and stop execution. Releases the resources associated with this CqQuery.

Throws:

CqClosedException - Further calls on this CqQuery instance except for getState() or getName().

CqException - - if failure during cleanup of CQ resources.

isRunning

boolean isRunning()

This allows to check if the CQ is in running or active.

Returns:

boolean true if running, false otherwise

isStopped

boolean isStopped()

This allows to check if the CQ is in stopped.

Returns:

boolean true if stopped, false otherwise

isClosed

boolean isClosed()

This allows to check if the CQ is closed.

Returns:

boolean true if closed, false otherwise

isDurable

boolean isDurable()

This allows to check if the CQ is durable.

Returns:

boolean true if durable, false otherwise

Since:

GemFire 5.5