Configuring an Interceptor on an EJB 3.0 Session Bean

You can designate one non-business method as the interceptor method for a stateless or stateful session bean (see "Using Annotations"). The method must have a signature of:

public Object <MethodName>(InvocationContext) throws Exception

For more information, see "Understanding EJB 3.0 Interceptors".

Using Annotations

Example 5-2 shows how to designate a method of a session bean class as an interceptor method using the @AroundInvoke annotation. Each time a client invokes a business method of this stateless session bean, OC4J intercepts the invocation and invokes the interceptor method myInterceptor. The client invocation proceeds only if the interceptor method returns InvocationContext.proceed().

Example 5-2 @AroundInvoke in an EJB 3.0 Session Bean

@Stateless
public class HelloWorldBean implements HelloWorld 
{
    public void sayHello() 
    {
        System.out.println("Hello!");
    }

    @AroundInvoke
    public Object myInterceptor(InvocationContext ctx) throws Exception 
    {
        Principal p = ctx.getEJBContext().getCallerPrincipal;
        if (!userIsValid(p))
        {
            throw new SecurityException(
                "Caller: '" + p.getName() +
                "' does not have permissions for method " + ctx.getMethod()
            );
        }
        return ctx.proceed();
    }
}