CDI provides standards-based and typesafe dependency injection in Java EE 6. It integrates well with other Java EE 6 technologies like EJB, JPA, JSF, and JAX-WS. Portable extensions facilitate a richer programming model. Weld is the reference implementation of CDI and is integrated into application servers like GlassFish and JBoss.

2. Software Engineering Manager

5. More stateful and less XML-centric than Spring

10. Bridge EJB (transactional tier) and JSF (presentation tier) in the platform

12. Producer – runtime polymorphism

13. Interceptors – decouple technical and business concerns

14. Decorators – decouple business concerns

15. Event notifications – decouple event producer and consumers

16. Contextual lifecycle management decouples bean lifecycles

21. Concrete class or decorated with @Decorator

25. META-INF of JAR

28. 0 or more qualifiers

29. Type @Inject @LoggedIn User user @Inject @LoggedIn User user Request Injection What ? (Type) Which one ? (Qualifier)

30. Basic – Sample Code public interface Greeting { public String greet(String name); } @Stateless public class GreetingService { @Inject Greeting greeting; public String greet(String name) { return greeting.greet(name); } } public class SimpleGreeting implements Greeting { public String greet(String name) { return “Hello “ + name; } }

31. Field and Method Injection public class CheckoutHandler { @Inject @LoggedIn User user; @Inject PaymentProcessor processor; @Inject void setShoppingCart(@Default Cart cart) { … } }

33. Makes the bean immutable

35. No direct dependency to any particular implementation (of many)

37. Qualifier – Sample Code @Fancy public class FancyGreeting implements Greeting { public String sayHello(String name) { return “Nice to meet you, hello “ + name; } } @Stateless public class GreetingService { @Inject @Fancy Greeting greeting; public String sayHello(String name) { return greeting.sayHello(name); } } @Qualifier @Retention(RUNTIME) @Target({METHOD, FIELD, PARAMETER, TYPE}) public @interface Fancy { }

38. Multiple Qualifiers and Qualifiers with Arguments public class CheckoutHandler { @Inject CheckoutHandler(@LoggedIn User user, @Reliable @PayBy(CREDIT_CARD) PaymentProcessor processor , @Default Cart cart) { ... } }

41. Explicitly enable an @Alternative bean using beans.xml

43. Disable one of the beans using @Alternative

44. Move one implementation out of classpath

47. Everywhere: @ApplicationScoped , @RequestScoped

48. Web app: @SessionScoped (serializable)

50. Typically defined by framework authors

56. Dynamic object construction at runtime

57. Bridge the gap with Java EE DI

58. Perform custom initialization not possible in a constructor

60. Defined in the same class as the “producer” method

61. Producer – Sample Code @SessionScoped public class Preferences implements Serializable { private PaymentStrategyType paymentStrategy; . . . @Produces @Preferred public PaymentStrategy getPaymentStrategy() { switch (paymentStrategy) { case CREDIT_CARD: return new CreditCardPaymentStrategy(); case CHECK: return new CheckPaymentStrategy(); case PAYPAL: return new PayPalPaymentStrategy(); default: return null; } } } @Inject @Preferred PaymentStrategy paymentStrategy; @SessionScoped

62. Disposer – Sample Code @Produces @RequestScoped Connection connect(User user) { return createConnection(user.getId(), user.getPassword()); } void close( @Disposes Connection connection) { connection.close(); }

67. Interceptors – Business Method (Logging) @InterceptorBinding @Retention(RUNTIME) @Target({METHOD,TYPE}) public @interface LoggingInterceptorBinding { } @LoggingInterceptorBinding public class MyManagedBean { . . . } @Interceptor @LoggingInterceptorBinding public class LogInterceptor { @AroundInvoke public Object log( InvocationContext context ) { System.out.println(context.getMethod().getName()); System.out.println(context.getParameters()); return context.proceed(); } }

68. Interceptors – Business Method (Transaction) @InterceptorBinding @Retention(RUNTIME) @Target({METHOD,TYPE}) public @interface Transactional { } @Transactional public class ShoppingCart { . . . } @Interceptor @Transactional public class @TransactionInterceptor { @Resource UserTransaction tx; @AroundInvoke public Object manageTransaction(InvocationContext context) { tx.begin() Object response = context.proceed(); tx.commit(); return response; } } http://blogs.sun.com/arungupta/entry/totd_151_transactional_interceptors_using public class ShoppingCart { @Transactional public void checkOut() { . . . }

69. Decorator – Sample Code public interface Account { public BigDecimal getBalance(); public User getOwner(); public void withdraw(BigDecimal amount); public void deposit(BigDecimal amount); } @Decorator public abstract class LargeTransactionDecorator implements Account { @Inject @Delegate @Any Account account; @PersistenceContext EntityManager em; public void withdraw(BigDecimal amount) { … } public void deposit(BigDecimal amount); … } } <beans ... <decorators> <class> org.example.LargeTransactionDecorator </class> </decorators> </beans>

73. An “observer” bean watches an event

74. Events can have qualifiers

76. Events – Sample Code @Inject @Any Event<PrintEvent> myEvent; void print() { . . . myEvent.fire ( new PrintEvent(5) ); } void onPrint( @Observes PrintEvent event){…} public class PrintEvent { public PrintEvent(int pages) { this.pages = pages; } . . . } void addProduct( @Observes(during = AFTER_SUCCESS) @Created Product product)

78. “ Stereotype stacking”

80. Stereotypes – Sample Code (Make Your Own) @RequestScoped @Transactional(requiresNew=true) @Secure @Named @Stereotype @Retention(RUNTIME) @Target(TYPE) public @interface Action {}

83. Loose coupling, Strong typing

84. Lesser errors due to typos in String-based names

85. Easier and better tooling

88. CDI runtime creates the instance when needed by the client

89. CDI runtime destroys the instance when the context ends

93. Can be enabled or disabled at deployment using “beans.xml”

94. Order of interceptors can be controlled using “beans.xml”

96. Monitoring: All EJBs exposed via JMX

97. Timers

98. Asynchronous, TX execution with <Future>

99. Declarative “convention over configuration” TX, Security

101. Built-in stereotypes for ease-of-development - @Model

106. ApplicationScope during any Web service invocation

109. Running CDI in Java SE environment

111. Integration with 3 rd -party frameworks like Spring, Seam, Wicket

112. New technology based upon the CDI programming model

114. Intercepts deployment of hybrid applications

115. Discover (using criteria), bind, track, inject the service

116. Metadata – filter, wait timeouts, dynamic binding http://blogs.sun.com/sivakumart/entry/typesafe_injection_of_dynamic_osgi

118. Integrates well with other Java EE 6 technologies

119. Portable Extensions facilitate richer programming model

122. glassfish.org

123. oracle.com/goto/glassfish

124. blogs.sun.com/theaquarium

125. youtube.com/GlassFishVideos

126. Follow @glassfish

127. http://docs.jboss.org/weld/reference/latest/en-US/html/

129. IDE Support

131. IDE Support http://blogs.jetbrains.com/idea/2009/11/cdi-jsr-299-run-with-me/

132. IDE Support http://docs.jboss.org/tools/whatsnew/

133. IDE Support http://docs.jboss.org/tools/whatsnew/

134. Qualifier – Sample Code X @Fancy public class SimpleGreeting implements Greeting { public String greet(String name) { return “Nice to meet you, hello “ + name; } } public interface Greeting { public String greet(String name); } @Inject Greeting greeting; @Inject @Default Greeting greeting; @Inject @Any Greeting greeting; @Inject @Fancy Greeting greeting; @Inject @Any @Fancy Greeting greeting; @Inject @Any @Default Greeting greeting; public class SimpleGreeting implements Greeting { public String greet(String name) { return “Hello “ + name; } }

135. Custom Scopes – Sample Code @ScopeType @Retention(RUNTIME) @Target({TYPE, METHOD}) public @interface ClusterScoped {} public @interface TransactionScoped {} public @interface ThreadScoped {}