EPStatementImpl (Esper API Documentation)

java.lang.Object
- com.espertech.esper.core.service.EPStatementImpl

All Implemented Interfaces:

EPIterable, EPListenable, EPStatement, EPStatementSPI
```
public class EPStatementImpl
extends Object
implements EPStatementSPI
```
Statement implementation for EPL statements.

Field Summary

Fields
Modifier and Type Field and Description

protected StatementContext statementContext

Fields
Modifier and Type	Field and Description
`protected StatementContext`	`statementContext`

Constructor Summary

Constructors
Constructor and Description
`EPStatementImpl(String expressionNoAnnotations, boolean isPattern, DispatchService dispatchService, StatementLifecycleSvc statementLifecycleSvc, long timeLastStateChange, boolean isBlockingDispatch, boolean isSpinBlockingDispatch, long msecBlockingTimeout, TimeSourceService timeSourceService, StatementMetadata statementMetadata, Object userObject, StatementContext statementContext, boolean isFailed, boolean nameProvided)` Ctor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addListener(StatementAwareUpdateListener listener)` Add a statement-aware listener that observes events.
`void`	`addListener(UpdateListener listener)` Add a listener to the statement.
`void`	`addListenerWithReplay(UpdateListener listener)` Add an update listener replaying current statement results to the listener.
`void`	`destroy()` Destroy the statement releasing all statement resources.
`Annotation[]`	`getAnnotations()` Returns EPL or pattern statement annotations provided in the statement text, if any.
`UpdateDispatchViewBase`	`getDispatchChildView()`
`EventType`	`getEventType()` Returns the type of events the iterable returns.
`String`	`getExpressionNoAnnotations()` Returns the statements expression without annotations.
`EPStatementListenerSet`	`getListenerSet()` Returns the set of listeners to the statement.
`String`	`getName()` Returns the statement name.
`Viewable`	`getParentView()` Returns the parent view.
`String`	`getServiceIsolated()` Returns the name of the isolated service provided is the statement is currently isolated in terms of event visibility and scheduling, or returns null if the statement is live in the engine.
`EPStatementState`	`getState()` Returns the statement's current state.
`Iterator<StatementAwareUpdateListener>`	`getStatementAwareListeners()` Returns an iterator of statement-aware update listeners.
`StatementContext`	`getStatementContext()` Returns the statement context.
`int`	`getStatementId()` Returns the statement id.
`StatementMetadata`	`getStatementMetadata()` Returns additional metadata about a statement.
`Object`	`getSubscriber()` Returns the current subscriber instance that receives statement results.
`String`	`getText()` Returns the underlying expression text.
`long`	`getTimeLastStateChange()` Returns the system time in milliseconds of when the statement last change state.
`Iterator<UpdateListener>`	`getUpdateListeners()` Returns an iterator of update listeners.
`Object`	`getUserObject()` Returns the application defined user data object associated with the statement, or null if none was supplied at time of statement creation.
`boolean`	`isDestroyed()` Returns true if the statement state is destroyed.
`boolean`	`isNameProvided()` True if an explicit statement name has been provided, false if the statement name is system-generated.
`boolean`	`isPattern()` Returns true if statement is a pattern
`boolean`	`isStarted()` Returns true if the statement state is started.
`boolean`	`isStopped()` Returns true if the statement state is stopped.
`Iterator<EventBean>`	`iterator()` Returns a concurrency-unsafe iterator over events representing statement results (pull API).
`Iterator<EventBean>`	`iterator(ContextPartitionSelector selector)` For use with statements that have a context declared and that may therefore have multiple context partitions, allows to iterate over context partitions selectively.
`void`	`removeAllListeners()` Remove all listeners to a statement.
`void`	`removeListener(StatementAwareUpdateListener listener)` Remove a statement-aware listener that observes events.
`void`	`removeListener(UpdateListener listener)` Remove a listeners to a statement.
`SafeIterator<EventBean>`	`safeIterator()` Returns a concurrency-safe iterator that iterates over events representing statement results (pull API) in the face of concurrent event processing by further threads.
`SafeIterator<EventBean>`	`safeIterator(ContextPartitionSelector selector)` For use with statements that have a context declared and that may therefore have multiple context partitions, allows to safe-iterate over context partitions selectively.
`void`	`setCurrentState(EPStatementState currentState, long timeLastStateChange)` Set statement state.
`void`	`setListeners(EPStatementListenerSet listenerSet, boolean isRecovery)` Sets the statement listeners.
`void`	`setParentView(Viewable viewable)` Sets the parent view.
`void`	`setServiceIsolated(String serviceIsolated)` Set the statement's isolated service name, or null to clear.
`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).
`void`	`start()` Start the statement.
`void`	`stop()` Stop the statement.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - statementContext
```
protected StatementContext statementContext
```
- Constructor Detail
  - EPStatementImpl
```
public EPStatementImpl(String expressionNoAnnotations,
                       boolean isPattern,
                       DispatchService dispatchService,
                       StatementLifecycleSvc statementLifecycleSvc,
                       long timeLastStateChange,
                       boolean isBlockingDispatch,
                       boolean isSpinBlockingDispatch,
                       long msecBlockingTimeout,
                       TimeSourceService timeSourceService,
                       StatementMetadata statementMetadata,
                       Object userObject,
                       StatementContext statementContext,
                       boolean isFailed,
                       boolean nameProvided)
```
    Ctor.
    
    Parameters:
    
    isPattern - is true to indicate this is a pure pattern expression
    
    dispatchService - for dispatching events to listeners to the statement
    
    statementLifecycleSvc - handles lifecycle transitions for the statement
    
    isBlockingDispatch - is true if the dispatch to listeners should block to preserve event generation order
    
    isSpinBlockingDispatch - true to use spin locks blocking to deliver results, as locks are usually uncontended
    
    msecBlockingTimeout - is the max number of milliseconds of block time
    
    timeLastStateChange - the timestamp the statement was created and started
    
    timeSourceService - time source provider
    
    statementMetadata - statement metadata
    
    userObject - the application define user object associated to each statement, if supplied
    
    statementContext - the statement service context
    
    expressionNoAnnotations - expression text witout annotations
    
    isFailed - indicator to start in failed state
    
    nameProvided - true to indicate a statement name has been provided and is not a system-generated name
- Method Detail
  - getStatementId
```
public int getStatementId()
```
    Description copied from interface: EPStatementSPI
    
    Returns the statement id.
    
    Specified by:
    
    getStatementId in interface EPStatementSPI
    
    Returns:
    
    statement id
  - start
```
public void start()
```
    Description copied from interface: EPStatement
    
    Start the statement.
    
    Specified by:
    
    start in interface EPStatement
  - stop
```
public void stop()
```
    Description copied from interface: EPStatement
    
    Stop the statement.
    
    Specified by:
    
    stop in interface EPStatement
  - destroy
```
public void destroy()
```
    Description copied from interface: EPStatement
    
    Destroy the statement releasing all statement resources.
    A destroyed statement cannot be started again.
    
    Specified by:
    
    destroy in interface EPStatement
  - getState
```
public EPStatementState getState()
```
    Description copied from interface: EPStatement
    
    Returns the statement's current state.
    
    Specified by:
    
    getState in interface EPStatement
    
    Returns:
    
    state enum
  - setCurrentState
```
public void setCurrentState(EPStatementState currentState,
                            long timeLastStateChange)
```
    Description copied from interface: EPStatementSPI
    
    Set statement state.
    
    Specified by:
    
    setCurrentState in interface EPStatementSPI
    
    Parameters:
    
    currentState - new current state
    
    timeLastStateChange - the timestamp the statement changed state
  - getParentView
```
public Viewable getParentView()
```
    Description copied from interface: EPStatementSPI
    
    Returns the parent view.
    
    Specified by:
    
    getParentView in interface EPStatementSPI
    
    Returns:
    
    viewable is the statement parent viewable
  - setParentView
```
public void setParentView(Viewable viewable)
```
    Description copied from interface: EPStatementSPI
    
    Sets the parent view.
    
    Specified by:
    
    setParentView in interface EPStatementSPI
    
    Parameters:
    
    viewable - is the statement viewable
  - getText
```
public String getText()
```
    Description copied from interface: EPStatement
    
    Returns the underlying expression text.
    
    Specified by:
    
    getText in interface EPStatement
    
    Returns:
    
    expression text
  - getName
```
public String getName()
```
    Description copied from interface: EPStatement
    
    Returns the statement name.
    
    Specified by:
    
    getName in interface EPStatement
    
    Returns:
    
    statement name
  - iterator
```
public Iterator<EventBean> iterator(ContextPartitionSelector selector)
```
    Description copied from interface: EPStatement
    
    For use with statements that have a context declared and that may therefore have multiple context partitions, allows to iterate over context partitions selectively.
    
    Specified by:
    
    iterator in interface EPStatement
    
    Parameters:
    
    selector - selects context partitions to consider
    
    Returns:
    
    iterator
  - safeIterator
```
public SafeIterator<EventBean> safeIterator(ContextPartitionSelector selector)
```
    Description copied from interface: EPStatement
    
    For use with statements that have a context declared and that may therefore have multiple context partitions, allows to safe-iterate over context partitions selectively.
    
    Specified by:
    
    safeIterator in interface EPStatement
    
    Parameters:
    
    selector - selects context partitions to consider
    
    Returns:
    
    safe iterator
  - iterator
```
public Iterator<EventBean> iterator()
```
    Description copied from interface: EPIterable
    
    Returns a concurrency-unsafe iterator over events representing statement results (pull API).
    The iterator is useful for applications that are single-threaded, or that coordinate the iterating thread with event processing threads that use the sendEvent method using application code locks or synchronization.
    The iterator returned by this method does not make any guarantees towards correctness of results and fail-behavior, if your application processes events into the engine instance using the sendEvent method by multiple threads.
    Use the safeIterator method for concurrency-safe iteration. Note the safe iterator requires applications to explicitly close the safe iterator when done iterating.
    
    Specified by:
    
    iterator in interface EPIterable
    
    Returns:
    
    event iterator
  - safeIterator
```
public SafeIterator<EventBean> safeIterator()
```
    Description copied from interface: EPIterable
    
    Returns a concurrency-safe iterator that iterates over events representing statement results (pull API) in the face of concurrent event processing by further threads.
    In comparison to the regular iterator, the safe iterator guarantees correct results even as events are being processed by other threads. The cost is that the iterator holds one or more locks that must be released via the close method. Any locks are acquired at the time this method is called.
    This method is a blocking method. It may block until statement processing locks are released such that the safe iterator can acquire any required locks.
    An application MUST explicitly close the safe iterator instance using the close method, to release locks held by the iterator. The call to the close method should be done in a finally block to make sure the iterator gets closed.
    Multiple safe iterators may be not be used at the same time by different application threads. A single application thread may hold and use multiple safe iterators however this is discouraged.
    
    Specified by:
    
    safeIterator in interface EPIterable
    
    Returns:
    
    safe iterator; NOTE: Must use the close method to close the safe iterator, preferably in a finally block
  - getEventType
```
public EventType getEventType()
```
    Description copied from interface: EPIterable
    
    Returns the type of events the iterable returns.
    
    Specified by:
    
    getEventType in interface EPIterable
    
    Returns:
    
    event type of events the iterator returns
  - getListenerSet
```
public EPStatementListenerSet getListenerSet()
```
    Returns the set of listeners to the statement.
    
    Specified by:
    
    getListenerSet in interface EPStatementSPI
    
    Returns:
    
    statement listeners
  - setListeners
```
public void setListeners(EPStatementListenerSet listenerSet,
                         boolean isRecovery)
```
    Description copied from interface: EPStatementSPI
    
    Sets the statement listeners.
    Care must be taken in the use of this method as unsynchronized modification to the listeners of a statement can yield problems.
    
    Specified by:
    
    setListeners in interface EPStatementSPI
    
    Parameters:
    
    listenerSet - set
    
    isRecovery - whether we are recovering
  - addListener
```
public void addListener(UpdateListener listener)
```
    Add a listener to the statement.
    
    Specified by:
    
    addListener in interface EPListenable
    
    Parameters:
    
    listener - to add
  - addListenerWithReplay
```
public void addListenerWithReplay(UpdateListener listener)
```
    Description copied from interface: EPStatement
    
    Add an update listener replaying current statement results to the listener.
    The listener receives current statement results as the first call to the update method of the listener, passing in the newEvents parameter the current statement results as an array of zero or more events. Subsequent calls to the update method of the listener are statement results.
    Current statement results are the events returned by the iterator or safeIterator methods.
    Delivery of current statement results in the first call is performed by the same thread invoking this method, while subsequent calls to the listener may deliver statement results by the same or other threads.
    Note: this is a blocking call, delivery is atomic: Events occurring during iteration and delivery to the listener are guaranteed to be delivered in a separate call and not lost. The listener implementation should minimize long-running or blocking operations.
    Delivery is only atomic relative to the current statement. If the same listener instance is registered with other statements it may receive other statement result s simultaneously.
    If a statement is not started an therefore does not have current results, the listener receives a single invocation with a null value in newEvents.
    
    Specified by:
    
    addListenerWithReplay in interface EPStatement
    
    Parameters:
    
    listener - to add
  - removeListener
```
public void removeListener(UpdateListener listener)
```
    Remove a listeners to a statement.
    
    Specified by:
    
    removeListener in interface EPListenable
    
    Parameters:
    
    listener - to remove
  - removeAllListeners
```
public void removeAllListeners()
```
    Remove all listeners to a statement.
    
    Specified by:
    
    removeAllListeners in interface EPListenable
  - addListener
```
public void addListener(StatementAwareUpdateListener listener)
```
    Description copied from interface: EPListenable
    
    Add a statement-aware listener that observes events.
    
    Specified by:
    
    addListener in interface EPListenable
    
    Parameters:
    
    listener - to add
  - removeListener
```
public void removeListener(StatementAwareUpdateListener listener)
```
    Description copied from interface: EPListenable
    
    Remove a statement-aware listener that observes events.
    
    Specified by:
    
    removeListener in interface EPListenable
    
    Parameters:
    
    listener - to remove
  - getStatementAwareListeners
```
public Iterator<StatementAwareUpdateListener> getStatementAwareListeners()
```
    Description copied from interface: EPListenable
    
    Returns an iterator of statement-aware update listeners.
    The returned iterator does not allow the remove operation.
    
    Specified by:
    
    getStatementAwareListeners in interface EPListenable
    
    Returns:
    
    iterator of statement-aware update listeners
  - getUpdateListeners
```
public Iterator<UpdateListener> getUpdateListeners()
```
    Description copied from interface: EPListenable
    
    Returns an iterator of update listeners.
    The returned iterator does not allow the remove operation.
    
    Specified by:
    
    getUpdateListeners in interface EPListenable
    
    Returns:
    
    iterator of update listeners
  - getTimeLastStateChange
```
public long getTimeLastStateChange()
```
    Description copied from interface: EPStatement
    
    Returns the system time in milliseconds of when the statement last change state.
    
    Specified by:
    
    getTimeLastStateChange in interface EPStatement
    
    Returns:
    
    time in milliseconds of last statement state change
  - isStarted
```
public boolean isStarted()
```
    Description copied from interface: EPStatement
    
    Returns true if the statement state is started.
    
    Specified by:
    
    isStarted in interface EPStatement
    
    Returns:
    
    true for started statements, false for stopped or destroyed statements.
  - isStopped
```
public boolean isStopped()
```
    Description copied from interface: EPStatement
    
    Returns true if the statement state is stopped.
    
    Specified by:
    
    isStopped in interface EPStatement
    
    Returns:
    
    true for stopped statements, false for started or destroyed statements.
  - isDestroyed
```
public boolean isDestroyed()
```
    Description copied from interface: EPStatement
    
    Returns true if the statement state is destroyed.
    
    Specified by:
    
    isDestroyed in interface EPStatement
    
    Returns:
    
    true for destroyed statements, false for started or stopped statements.
  - setSubscriber
```
public void setSubscriber(Object subscriber)
```
    Description copied from interface: EPStatement
    
    Attaches a subscriber to receive statement results, or removes a previously set subscriber (by providing a null value).
    Only a single subscriber may be set for a statement. If this method is invoked twice any previously-set subscriber is no longer used.
    
    Specified by:
    
    setSubscriber in interface EPStatement
    
    Parameters:
    
    subscriber - to attach, or null to remove the previously set subscriber
  - setSubscriber
```
public void setSubscriber(Object subscriber,
                          String methodName)
```
    Description copied from interface: EPStatement
    
    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).
    Only a single subscriber may be set for a statement. If this method is invoked twice any previously-set subscriber is no longer used.
    
    Specified by:
    
    setSubscriber in interface EPStatement
    
    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
  - getSubscriber
```
public Object getSubscriber()
```
    Description copied from interface: EPStatement
    
    Returns the current subscriber instance that receives statement results.
    
    Specified by:
    
    getSubscriber in interface EPStatement
    
    Returns:
    
    subscriber object, or null to indicate that no subscriber is attached
  - isPattern
```
public boolean isPattern()
```
    Description copied from interface: EPStatement
    
    Returns true if statement is a pattern
    
    Specified by:
    
    isPattern in interface EPStatement
    
    Returns:
    
    true if statement is a pattern
  - getStatementMetadata
```
public StatementMetadata getStatementMetadata()
```
    Description copied from interface: EPStatementSPI
    
    Returns additional metadata about a statement.
    
    Specified by:
    
    getStatementMetadata in interface EPStatementSPI
    
    Returns:
    
    statement metadata
  - getUserObject
```
public Object getUserObject()
```
    Description copied from interface: EPStatement
    
    Returns the application defined user data object associated with the statement, or null if none was supplied at time of statement creation.
    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 creation as a parameter the create method.
    
    Specified by:
    
    getUserObject in interface EPStatement
    
    Returns:
    
    user object or null if none defined
  - getAnnotations
```
public Annotation[] getAnnotations()
```
    Description copied from interface: EPStatement
    
    Returns EPL or pattern statement annotations provided in the statement text, if any.
    See the annotation com.espertech.esper.client.annotation package for available annotations.
    
    Specified by:
    
    getAnnotations in interface EPStatement
    
    Returns:
    
    annotations or a zero-length array if no annotaions have been specified.
  - getStatementContext
```
public StatementContext getStatementContext()
```
    Description copied from interface: EPStatementSPI
    
    Returns the statement context.
    
    Specified by:
    
    getStatementContext in interface EPStatementSPI
    
    Returns:
    
    statement context
  - getExpressionNoAnnotations
```
public String getExpressionNoAnnotations()
```
    Description copied from interface: EPStatementSPI
    
    Returns the statements expression without annotations.
    
    Specified by:
    
    getExpressionNoAnnotations in interface EPStatementSPI
    
    Returns:
    
    expression
  - getServiceIsolated
```
public String getServiceIsolated()
```
    Description copied from interface: EPStatement
    
    Returns the name of the isolated service provided is the statement is currently isolated in terms of event visibility and scheduling, or returns null if the statement is live in the engine.
    
    Specified by:
    
    getServiceIsolated in interface EPStatement
    
    Returns:
    
    isolated service name or null for statements that are not currently isolated
  - setServiceIsolated
```
public void setServiceIsolated(String serviceIsolated)
```
    Description copied from interface: EPStatementSPI
    
    Set the statement's isolated service name, or null to clear.
    
    Specified by:
    
    setServiceIsolated in interface EPStatementSPI
    
    Parameters:
    
    serviceIsolated - name of isolated service
  - isNameProvided
```
public boolean isNameProvided()
```
    Description copied from interface: EPStatementSPI
    
    True if an explicit statement name has been provided, false if the statement name is system-generated.
    
    Specified by:
    
    isNameProvided in interface EPStatementSPI
    
    Returns:
    
    indicator if statement name exists
  - getDispatchChildView
```
public UpdateDispatchViewBase getDispatchChildView()
```

Class EPStatementImpl

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

statementContext

Constructor Detail

EPStatementImpl

Method Detail

getStatementId

start

stop

destroy

getState

setCurrentState

getParentView

setParentView

getText

getName

iterator

safeIterator

iterator

safeIterator

getEventType

getListenerSet

setListeners

addListener

addListenerWithReplay

removeListener

removeAllListeners

addListener

removeListener

getStatementAwareListeners

getUpdateListeners

getTimeLastStateChange

isStarted

isStopped

isDestroyed

setSubscriber

setSubscriber

getSubscriber

isPattern

getStatementMetadata

getUserObject

getAnnotations

getStatementContext

getExpressionNoAnnotations

getServiceIsolated

setServiceIsolated

isNameProvided

getDispatchChildView