9.2.10.2. Use Interceptors with CDI

Example 9.19. Interceptors without CDI

Without CDI, interceptors have two problems.
  • The bean must specify the interceptor implementation directly.
  • Every bean in the application must specify the full set of interceptors in the correct order. This makes adding or removing interceptors on an application-wide basis time-consuming and error-prone. 
@Interceptors({
  SecurityInterceptor.class,
  TransactionInterceptor.class,
  LoggingInterceptor.class
})
@Stateful public class BusinessComponent {
  ...
}

Procedure 9.7. Use interceptors with CDI

  1. Define the interceptor binding type.

    @InterceptorBinding
@Retention(RUNTIME)
@Target({TYPE, METHOD})
public @interface Secure {}

  2. Mark the interceptor implementation.

    @Secure
@Interceptor
public class SecurityInterceptor {
  @AroundInvoke
  public Object aroundInvoke(InvocationContext ctx) throws Exception {
    // enforce security ...
    return ctx.proceed();
    }
}

  3. Use the interceptor in your business code.

    @Secure
public class AccountManager {
  public boolean transfer(Account a, Account b) {
    ...
  }
}

  4. Enable the interceptor in your deployment, by adding it to META-INF/beans.xml or WEB-INF/beans.xml.

    <beans>
  <interceptors>
    <class>com.acme.SecurityInterceptor</class>
    <class>com.acme.TransactionInterceptor</class>
  </interceptors>
</beans>
    The interceptors are applied in the order listed.
Result:

CDI simplifies your interceptor code and makes it easier to apply to your business code.

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