How to: Implement a BatchMessageListenerContainer for bulk consuming a JMS queue
I recently faced the need for a JMS consumer in Spring Integration - capable of consuming burst of high volume without stressing my target Oracle database with too many comm
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Well - this is a simple and compact solution that is entirely based on a single class derived from DefaultMessageListenerContainer.
I have only tested with message-driven-channel-adapter and a ChainedTransactionManager though - since this is sort of the basic scenario when needing to do stuff like this.
This is the code:
package dk.itealisten.myservice.spring.components; import org.springframework.jms.listener.DefaultMessageListenerContainer; import javax.jms.Destination; import javax.jms.JMSException; import javax.jms.Message; import javax.jms.MessageConsumer; import java.util.ArrayList; import java.util.Enumeration; public class BatchMessageListenerContainer extends DefaultMessageListenerContainer { public static final int DEFAULT_BATCH_SIZE = 100; public int batchSize = DEFAULT_BATCH_SIZE; /** * Override the method receiveMessage to return an instance of BatchMessage - an inner class being declared further down. */ @Override protected Message receiveMessage(MessageConsumer consumer) throws JMSException { BatchMessage batch = new BatchMessage(); while (!batch.releaseAfterMessage(super.receiveMessage(consumer))) ; return batch.messages.size() == 0 ? null : batch; } /** * As BatchMessage implements the javax.jms.Message interface it fits perfectly into the DMLC - only caveat is that SimpleMessageConverter dont know how to convert it to a Spring Integration Message - but that can be helped. * As BatchMessage will only serve as a container to carry the actual javax.jms.Message's from DMLC to the MessageListener it need not provide meaningful implementations of the methods of the interface as long as they are there. */ protected class BatchMessage implements Message { public ArrayList<Message> messages = new ArrayList<Message>(); /** * Add message to the collection of messages and return true if the batch meets the criteria for releasing it to the MessageListener. */ public boolean releaseAfterMessage(Message message) { if (message != null) { messages.add(message); } // Are we ready to release? return message == null || messages.size() >= batchSize; } // Below is only dummy-implementations of the abstract methods of javax.jms.Message @Override public String getJMSMessageID() throws JMSException { return null; } @Override public void setJMSMessageID(String s) throws JMSException { } @Override public long getJMSTimestamp() throws JMSException { return 0; } @Override public void setJMSTimestamp(long l) throws JMSException { } @Override public byte[] getJMSCorrelationIDAsBytes() throws JMSException { return new byte[0]; } @Override public void setJMSCorrelationIDAsBytes(byte[] bytes) throws JMSException { } @Override public void setJMSCorrelationID(String s) throws JMSException { } @Override public String getJMSCorrelationID() throws JMSException { return null; } @Override public Destination getJMSReplyTo() throws JMSException { return null; } @Override public void setJMSReplyTo(Destination destination) throws JMSException { } @Override public Destination getJMSDestination() throws JMSException { return null; } @Override public void setJMSDestination(Destination destination) throws JMSException { } @Override public int getJMSDeliveryMode() throws JMSException { return 0; } @Override public void setJMSDeliveryMode(int i) throws JMSException { } @Override public boolean getJMSRedelivered() throws JMSException { return false; } @Override public void setJMSRedelivered(boolean b) throws JMSException { } @Override public String getJMSType() throws JMSException { return null; } @Override public void setJMSType(String s) throws JMSException { } @Override public long getJMSExpiration() throws JMSException { return 0; } @Override public void setJMSExpiration(long l) throws JMSException { } @Override public long getJMSDeliveryTime() throws JMSException { return 0; } @Override public void setJMSDeliveryTime(long l) throws JMSException { } @Override public int getJMSPriority() throws JMSException { return 0; } @Override public void setJMSPriority(int i) throws JMSException { } @Override public void clearProperties() throws JMSException { } @Override public boolean propertyExists(String s) throws JMSException { return false; } @Override public boolean getBooleanProperty(String s) throws JMSException { return false; } @Override public byte getByteProperty(String s) throws JMSException { return 0; } @Override public short getShortProperty(String s) throws JMSException { return 0; } @Override public int getIntProperty(String s) throws JMSException { return 0; } @Override public long getLongProperty(String s) throws JMSException { return 0; } @Override public float getFloatProperty(String s) throws JMSException { return 0; } @Override public double getDoubleProperty(String s) throws JMSException { return 0; } @Override public String getStringProperty(String s) throws JMSException { return null; } @Override public Object getObjectProperty(String s) throws JMSException { return null; } @Override public Enumeration getPropertyNames() throws JMSException { return null; } @Override public void setBooleanProperty(String s, boolean b) throws JMSException { } @Override public void setByteProperty(String s, byte b) throws JMSException { } @Override public void setShortProperty(String s, short i) throws JMSException { } @Override public void setIntProperty(String s, int i) throws JMSException { } @Override public void setLongProperty(String s, long l) throws JMSException { } @Override public void setFloatProperty(String s, float v) throws JMSException { } @Override public void setDoubleProperty(String s, double v) throws JMSException { } @Override public void setStringProperty(String s, String s1) throws JMSException { } @Override public void setObjectProperty(String s, Object o) throws JMSException { } @Override public void acknowledge() throws JMSException { } @Override public void clearBody() throws JMSException { } @Override public <T> T getBody(Class<T> aClass) throws JMSException { return null; } @Override public boolean isBodyAssignableTo(Class aClass) throws JMSException { return false; } } }Below is a sample showing how it could be used in a Spring application context:
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:int="http://www.springframework.org/schema/integration" xmlns:jms="http://www.springframework.org/schema/integration/jms" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd http://www.springframework.org/schema/integration http://www.springframework.org/schema/integration/spring-integration-4.0.xsd http://www.springframework.org/schema/integration/jms http://www.springframework.org/schema/integration/jms/spring-integration-jms-4.0.xsd"> <!-- Plug in the BatchMessageListenerContainer in a message-driven-channel-adapter --> <jms:message-driven-channel-adapter container-class="dk.itealisten.myservice.spring.components.BatchMessageListenerContainer" acknowledge="transacted" channel="from.mq" concurrent-consumers="5" max-concurrent-consumers="15" connection-factory="jmsConnectionFactory" transaction-manager="transactionManager" destination="my.mq.queue" /> <!-- Flow processing the BatchMessages being posted on the "from.mq" channel --> <int:chain input-channel="from.mq" output-channel="nullChannel"> <int:splitter expression="payload.messages" /> <!-- This is where we deal with conversion to spring messages as the payload is now a single standard javax.jms.Message implementation --> <int:transformer ref="smc" method="fromMessage"/> <!-- And finally we persist --> <int:service-activator ref="jdbcPublisher" method="persist"/> </int:chain> <!-- Various supporting beans --> <!-- A bean to handle the database persistance --> <bean id="jdbcPersistor" class="dk.itealisten.myservice.spring.components.JdbcPersistor" p:dataSource-ref="dataSource" /> <!-- A bean to handle the conversion that could not take place in the MessageListener as it don't know how to convert a BatchMessage --> <bean id="smc" class="org.springframework.jms.support.converter.SimpleMessageConverter"/> <!-- Transaction manager must make sure messages are committed outbound (JDBC) before cleaned up inbound (JMS). --> <bean id="transactionManager" class="org.springframework.data.transaction.ChainedTransactionManager"> <constructor-arg name="transactionManagers"> <list> <bean class="org.springframework.jms.connection.JmsTransactionManager" p:connectionFactory-ref="jmsConnectionFactory" /> <bean class="org.springframework.jdbc.datasource.DataSourceTransactionManager" p:dataSource-ref="dataSource" /> </list> </constructor-arg> </bean>讨论(0)
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