streams.esper

Class EsperStatementSubscriber

java.lang.Object

streams.esper.EsperStatementSubscriber

Direct Known Subclasses:

EsperTrimmedStatementSubscriber

public class EsperStatementSubscriber
extends Object

The subscriber outputs data from an EPStatement to a Streams QueueService.

A subscriber object directly binds query results to a Java object. According the the Esper documentation a subscriber is much faster than an UpdateListener.

This class provides a generic implementation of a subscriber. As such it needs to know (i) the Streams sink it shall write data to and (ii) the keys for the Streams Data item. The subscriber follows no implementation pattern but requiring the subscriber class to implement an update method. This #update(Object...) method is simply requires to have an array of or a fixed number of objects as parameters. To have a generic implementation, we need to know the keys (in the extreme only the number of parameters) for the Streams Data item.

Since:

0.0.1

Version:

0.3.0

Author:

Thomas Scharrenbach

Field Summary

Fields

Modifier and Type	Field and Description
static String	KEY_STREAM Key of the name of the stream in data items.

Constructor Summary

Constructors

Constructor and Description
EsperStatementSubscriber(List<stream.io.Sink> sinksList, String[] keys) Create a new subscriber with the specified keys writing to the specified Sink.

Method Summary

Methods

Modifier and Type	Method and Description
void	update(Map<String,Serializable> values)
void	update(Serializable... values)
protected void	write(stream.Data item) Write the data item to all sinks.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

KEY_STREAM

public static final String KEY_STREAM

Key of the name of the stream in data items.

Since:

0.3.0

See Also:

Constant Field Values

Constructor Detail

EsperStatementSubscriber

public EsperStatementSubscriber(List<stream.io.Sink> sinksList,
                        String[] keys)

Create a new subscriber with the specified keys writing to the specified Sink.

Parameters:

sinksList -

keys -

Since:

0.0.1

Method Detail

update

public void update(Serializable... values)
            throws Exception

Parameters:

values - the values of an Esper event.

Throws:

Exception

Since:

0.0.1

update

public void update(Map<String,Serializable> values)
            throws Exception

Parameters:

values - the values of an Esper event.

Throws:

Exception

Since:

0.0.1

write

protected void write(stream.Data item)
              throws Exception

Write the data item to all sinks.

Parameters:

item -

Throws:

Exception

Since:

0.3.0