com.espertech.esper.runtime.client

Interface EPStatement

All Superinterfaces:

EPIterable, EPListenable

All Known Subinterfaces:

EPStatementSPI

All Known Implementing Classes:

EPStatementImpl

public interface EPStatement
extends EPListenable, EPIterable

The statement is the means to attach callbacks to receive statement results (push, observer) and to object current results using pull.

Method Summary

Modifier and Type	Method and Description
Annotation[]	getAnnotations() Returns statement annotations.
String	getDeploymentId() Returns the deployment id.
com.espertech.esper.common.client.EventType	getEventType() Returns the type of events the statement pushes to listeners or returns for iterator.
String	getName() Returns the statement name.
Object	getProperty(com.espertech.esper.common.client.util.StatementProperty field) Returns a statement property value.
Object	getSubscriber() Returns the current subscriber instance that receives statement results.
Object	getUserObjectCompileTime() Returns the application defined user data object associated with the statement at compile time, or null if none was supplied at time of statement compilation.
Object	getUserObjectRuntime() Returns the application defined user data object associated with the statement at deployment time, or null if none was supplied at time of deployment.
boolean	isDestroyed() Returns true if the statement has been undeployed.
void	setSubscriber(Object subscriber) Attaches a subscriber to receive statement results, or removes a previously set subscriber (by providing a null value).
void	setSubscriber(Object subscriber, String methodName) Attaches a subscriber to receive statement results by calling the method with the provided method name, or removes a previously set subscriber (by providing a null value).

Methods inherited from interface com.espertech.esper.runtime.client.EPListenable

addListener, addListenerWithReplay, getUpdateListeners, removeAllListeners, removeListener

Methods inherited from interface com.espertech.esper.runtime.client.EPIterable

iterator, iterator, safeIterator, safeIterator

Method Detail

getEventType

com.espertech.esper.common.client.EventType getEventType()

Returns the type of events the statement pushes to listeners or returns for iterator.

Returns:

event type of events the iterator returns and that listeners receive

getAnnotations

Annotation[] getAnnotations()

Returns statement annotations.

See the annotation com.espertech.esper.common.client.annotation package for available annotations. Application can define their own annotations.

Returns:

annotations or a zero-length array if no annotaions have been specified.

getName

String getName()

Returns the statement name.

Returns:

statement name

getDeploymentId

String getDeploymentId()

Returns the deployment id.

Returns:

deployment id

getProperty

Object getProperty(com.espertech.esper.common.client.util.StatementProperty field)

Returns a statement property value.

Parameters:

field - statement property value

Returns:

property or null if not set

isDestroyed

boolean isDestroyed()

Returns true if the statement has been undeployed.

Returns:

true for undeployed statements, false for deployed statements.

setSubscriber

void setSubscriber(Object subscriber)
            throws EPSubscriberException

Attaches a subscriber to receive statement results, or removes a previously set subscriber (by providing a null value).

Note: Requires the allow-subscriber compiler options.

Only a single subscriber may be set for a statement. If this method is invoked twice any previously-set subscriber is no longer used.

Parameters:

subscriber - to attach, or null to remove the previously set subscriber

Throws:

EPSubscriberException - if the subscriber does not provide the methods needed to receive statement results

setSubscriber

void setSubscriber(Object subscriber,
                   String methodName)
            throws EPSubscriberException

Attaches a subscriber to receive statement results by calling the method with the provided method name, or removes a previously set subscriber (by providing a null value).

Note: Requires the allow-subscriber compiler options.

Only a single subscriber may be set for a statement. If this method is invoked twice any previously-set subscriber is no longer used.

Parameters:

subscriber - to attach, or null to remove the previously set subscriber

methodName - the name of the method to invoke, or null for the "update" method

Throws:

EPSubscriberException - if the subscriber does not provide the methods needed to receive statement results

getSubscriber

Object getSubscriber()

Returns the current subscriber instance that receives statement results.

Returns:

subscriber object, or null to indicate that no subscriber is attached

getUserObjectCompileTime

Object getUserObjectCompileTime()

Returns the application defined user data object associated with the statement at compile time, or null if none was supplied at time of statement compilation.

The user object is a single, unnamed field that is stored with every statement. Applications may put arbitrary objects in this field or a null value.

User objects are passed at time of statement compilation via options.

Returns:

user object or null if none defined

getUserObjectRuntime

Object getUserObjectRuntime()

Returns the application defined user data object associated with the statement at deployment time, or null if none was supplied at time of deployment.

The user object is a single, unnamed field that is stored with every statement. Applications may put arbitrary objects in this field or a null value.

User objects are passed at time of deployment via options.

Returns:

user object or null if none defined