Introduction to JCA and MDB

Transcript

1. Introduction to 
 JCA and MDB HASUNUMA Kenji GlassFish Users Group Japan k.hasunuma@coppermine.jp Twitter: @khasunuma
2. What's JCA? • JCA (Java Connector Architecture) brings integration between systems • JCA is also base of Java EE servers • Almost Java EE developer have been used JCA
3. JCA Overview External System 
 (e.g. EIS) Java EE Resource Adapter (.rar) Web app. (.war) Outbound Inbound Java Connector 
 Architecture (JCA)
4. Contracts (1/2) since JCA 1.0 (J2EE 1.3) • Connection management (Connection pooling) • Transaction management (w/JTA) • Security management (w/JAAS)
5. Contracts (2/2) since JCA 1.5 (J2EE 1.4) • Life cycle management • Work management • Transaction inflow management • Message inflow management
6. Application Architecture ConnectionFactory EJB Connection External System getConnection JNDI lookup Outbound Inbound I/F
7. Application c.f. JMS ConnectionFactory EJB Connection JMS broker getConnection JNDI lookup Outbound Inbound JMS
8. Application c.f. JDBC DataSource EJB Connection RDBMS getConnection JNDI lookup SQL JDBC
9. Programming w/JCA • Many cases, JCA resource adapter is provided by each systems • Recently JCA is mainly used to manage message inflow • In JCA 1.7 (Java EE 7/8), properties are set by annotations
10. Outbound @ConnectionFactoryDefinition( name = "java:comp/env/OutboundConnectionFactory", interfacename = com.example.jca.OutboundConnectionFactory, resourceAdapter = "some-rar", ... ) @Stateless public class ExampleMessageSender { @Resource(lookup = "java.comp/env/OutboundConnectionFactory") OutboundConnectionFactory factory; public void send(...) { try (OutboundConnection conn = factory.createConnection()) { ... } catch (Exception e) { ... } } }
11. Attention • Session Bean SHOULD NOT be used to listen messages • SHOULD use Message Driven Bean (MDB) to listen messages
12. What's MDB? • EJB specified for listening messages • Have a callback method and handle inbound messages provided by JCA • MDB adapts both async and sync communication
13. Inbound @MessageDriven( activationConfig = { @ActivationConfigProperty(propertyName = ..., propertyValue = ...), ... } ) public class ExampleMessageListener implements MessageListener { public void onMessage(Message message) { ... } } Callback method invoked by the Resource Adapter
14. Use case: Payara Micro • Payara Micro connects other systems on cloud via JCA adapters; • Apache Kafka • MQTT (Mosquitto, etc.) • Amazon SQS • Microsoft Azure Service Bus
15. Why MQ? • System/service requirements are different each other • Now various systems/services are integrated on cloud platforms • MQ (i.g. Async) often resolves impedance matching between each systems/services
16. JCA is ... • JCA (Java Connector Architecture) brings integration between systems • JCA is also base of Java EE servers, e.g. JMS, JDBC • Almost Java EE developer have been used JCA as JDBC data source
17. Introduction to JCA and MDB HASUNUMA Kenji GlassFish Users Group Japan k.hasunuma@coppermine.jp Twitter: @khasunuma