org.jberet.support.io

Class JmsItemReader

java.lang.Object

org.jberet.support.io.ItemReaderWriterBase

org.jberet.support.io.JmsItemReaderWriterBase

org.jberet.support.io.JmsItemReader

All Implemented Interfaces:

javax.batch.api.chunk.ItemReader

@Named
 @Dependent
public class JmsItemReader
extends JmsItemReaderWriterBase
implements javax.batch.api.chunk.ItemReader

An implementation of javax.batch.api.chunk.ItemReader that reads data items from a JMS destination. It can reads the following JMS message types:

• ObjectMessage: the object contained in the message is retrieved and returned;
• MapMessage: a new java.util.Map is created, populated with the data contained in the incoming MapMessage, and returned;
• TextMessage: the text contained in the message is retrieved and returned;
• Message: but not one of its subtype, null is returned.

If beanType is set to javax.jms.Message, readItem() returns the incoming JMS message as is. Otherwise, readItem() method determines the actual data type based on the message type.

This reader ends when any of the following occurs:

• receiveTimeout (in milliseconds) has elapsed when trying to receive a message from the destination;
• any null body is retrieved from a message;
• any message is of type Message, but not one of its subtype.

Since:

1.1.0

See Also:

JmsItemWriter, JmsItemReaderWriterBase

Field Summary

Fields

Modifier and Type	Field and Description
protected Class	beanType The fully-qualified class name of the data item to be returned from readItem() method.
protected javax.jms.MessageConsumer	consumer
protected String	messageSelector Only messages with properties matching the message selector expression are delivered.
protected long	receiveTimeout The number of milliseconds a JMS MessageConsumer blocks until a message arrives.

Fields inherited from class org.jberet.support.io.JmsItemReaderWriterBase

connection, connectionFactory, connectionFactoryInstance, connectionFactoryLookupName, destination, destinationInstance, destinationLookupName, session, sessionMode

Fields inherited from class org.jberet.support.io.ItemReaderWriterBase

NEW_LINE, resource, skipBeanValidation

Constructor Summary

Constructors

Constructor and Description
JmsItemReader()

Method Summary

Modifier and Type	Method and Description
Serializable	checkpointInfo()
void	close()
void	open(Serializable checkpoint)
Object	readItem()

Methods inherited from class org.jberet.support.io.ItemReaderWriterBase

getInputStream, getOutputStream, getValidator, validate

Methods inherited from class java.lang.Object

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

Field Detail

receiveTimeout

@Inject
protected long receiveTimeout

The number of milliseconds a JMS MessageConsumer blocks until a message arrives. Optional property, and defaults to 0, which means it blocks indefinitely.

messageSelector

@Inject
protected String messageSelector

Only messages with properties matching the message selector expression are delivered. A value of null or an empty string indicates that there is no message selector for the message consumer. See JMS API Session.createConsumer(javax.jms.Destination, java.lang.String)

beanType

@Inject
protected Class beanType

The fully-qualified class name of the data item to be returned from readItem() method. Optional property and defaults to null. If it is specified, its valid value is:

• javax.jms.Message: an incoming JMS message is returned as is.

When this property is not specified, readItem() method returns an object whose actual type is determined by the incoming JMS message type.

consumer

protected javax.jms.MessageConsumer consumer

Constructor Detail

JmsItemReader

public JmsItemReader()

Method Detail

open

public void open(Serializable checkpoint)
          throws Exception

Specified by:

open in interface javax.batch.api.chunk.ItemReader

Overrides:

open in class JmsItemReaderWriterBase

Throws:

Exception

readItem

public Object readItem()
                throws Exception

Specified by:

readItem in interface javax.batch.api.chunk.ItemReader

Throws:

Exception

checkpointInfo

public Serializable checkpointInfo()
                            throws Exception

Specified by:

checkpointInfo in interface javax.batch.api.chunk.ItemReader

Throws:

Exception

close

public void close()

Specified by:

close in interface javax.batch.api.chunk.ItemReader

Overrides:

close in class JmsItemReaderWriterBase