S314168 - What's New in Enterprise Java Bean Technology @ JavaOne Brazil 2010
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Transcript of S314168 - What's New in Enterprise Java Bean Technology @ JavaOne Brazil 2010
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What's New in Enterprise JavaBean TechnologyArun Gupta, Java EE & GlassFish Guyblogs.sun.com/arungupta, @arungupta
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Beijing 2010
December 13–16, 2010
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The following is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions.The development, release, and timing of any features or functionality described for Oracle’s products remains at the sole discretion of Oracle.
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Agenda
• Introduction• Ease of Use Improvements• New Functionality
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EJB 3.1 Specification
• Goals– Continued focus on ease-of-use– New features
• JSR (Java Specification Request) 318– Expert Group Formed – August 2007– Public Draft – October 2008– Proposed Final Draft – March 2009– Final Specification – December 2009
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Ease of Use Improvements
• Optional Local Business Interfaces• Simplified Packaging• EJB 3.1 “Lite” API• Portable Global JNDI Names• Simple Component Testing
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Session BeanWith “No-interface” View
@Statelesspublic class HelloBean {
public String sayHello(String msg) { return “Hello “ + msg; }}
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No-interface View Client
@EJB HelloBean h;
...
h.sayHello(“bob”);
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JavaTM EE Platform 5 Packaging
foo.ear
WEB-INF/web.xml
WEB-INF/classes/
com/acme/FooServlet.class
WEB-INF/classes
com/acme/Foo.class
foo_web.war
com/acme/FooBean.classcom/acme/Foo.class
foo_ejb.jar
foo.ear
lib/foo_common.jar
com/acme/Foo.class
WEB-INF/web.xml
WEB-INF/classes/
com/acme/FooServlet.class
foo_web.war
com/acme/FooBean.class
foo_ejb.jar
OR
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foo.warWEB-INF/classes/com/acme/
FooServlet.class
FooBean.class
Simplified Packaging
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EJB 3.1 “Lite”
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Portable EJB JNDI Names
Each session bean gets the following entries :
• Globally unique namejava:global[/<app-name>]/<module-name>/<ejb-name>
• Unique name within same application java:app/<module-name>/<ejb-name>
• Unique name within defining modulejava:module/<ejb-name>
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Session Bean
@Stateless
public class HelloBean implements Hello {
public String sayHello(String msg) {
return “Hello “ + msg;
}
}
If deployed as hello.jar, JNDI entries are:
java:global/hello/HelloBeanjava:app/hello/HelloBeanjava:module/HelloBean
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Simple Testing : Session Bean
@Stateless
@Local(Bank.class)
public class BankBean implements Bank {
@PersistenceContext EntityManager accountDB;
public String createAccount(AcctDetails d)
{ … }
public void removeAccount(String acctID)
{ … }
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Embeddable API
public class BankTester {
public static void main(String[] args) {
EJBContainer container =
EJBContainer.createEJBContainer();
// Acquire Local EJB reference
Bank bank = (Bank) container.getContext().
lookup(“java:global/bank/BankBean”);
testAccountCreation(bank);
container.close();
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Test Client Execution
% java -classpath bankClient.jar :
bank.jar :
javaee.jar :
<vendor_rt>.jar
com.acme.BankTester
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New Features
• Singletons• Startup / Shutdown callbacks• Automatic timer creation
– Cron-like syntax
• Asynchronous session bean invocations
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Singleton
@Singleton
public class SharedBean {
private SharedData shared;
@PostConstruct
private void init() {
shared = ...;
}
public int getXYZ() {
return shared.xyz;
}
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Singleton Concurrency Options
• Single threaded (default)– For consistency with all existing bean types
• Container Managed Concurrency– Control access via method-level locking metadata
• Bean Managed Concurrency – All concurrent invocations have access to bean instance
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Startup / Shutdown Callbacks
@Singleton
@Startup
public class StartupBean {
@PostConstruct
private void onStartup() { … }
@PreDestroy
private void onShutdown() { … }
}
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Timers
• Automatically created EJB Timers• Calendar-based Timers – cron like semantics
– Every 14th minute within the hour, for the hours 1 and 2 am(minute=”*/14”, hour=”1,2”)
– Every 10 seconds starting at 30(second=”30/10”)
– Every 5 minutes of every hour(minute=”*/5”, hour=”*”)
– 2pm on Last Thur of Nov of every year(hour=”14”, dayOfMonth=”Last Thu”, month=”Nov”)
– Every Mon & Wed midnight @Schedule(dayOfWeek=”Mon,Wed”)
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Automatic Timer Creation
@Stateless
public class BankBean {
@PersistenceContext EntityManager accountDB;
@Resource javax.mail.Session mailSession;
// Callback the last day of each month at 8 a.m.
@Schedule(hour=”8”, dayOfMonth=”Last”)
void sendMonthlyBankStatements() {
...
}
}
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Asynchronous Session Beans
• Control returns to the client before the container dispatches invocation to a bean instance
• @Asynchronous – method or class• Return type – void or Future<V>• “Fire and and Forget” or async results via
Future<V>• Best effort delivery – persistent delivery
guarantees are not required by spec• Transaction context does not propagate
– REQUIRED → REQUIRED_NEW
• Security principal propagates
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Asynchronous Session BeansCode Sample
@Stateless@Asynchronouspublic class SimpleAsyncEJB { public Future<Integer> addNumbers(int n1, int n2) { Integer result;
result = n1 + n2; try { // simulate JPA queries + reading file system Thread.currentThread().sleep(2000); } catch (InterruptedException ex) { ex.printStackTrace(); }
return new AsyncResult(result); }}
http://blogs.sun.com/arungupta/entry/totd_137_asynchronous_ejb_a
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References
• glassfish.org• blogs.sun.com/theaquarium• youtube.com/user/GlassFishVideos• facebook.com/glassfish• Follow @glassfish
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What's New in Enterprise JavaBean Technology
Arun Gupta, Java EE & GlassFish Guyblogs.sun.com/arungupta, @arungupta