JavaEE Globally Catch Runtime exception

Question

I want to "globally" catch a Runtime exception, now this sounds silly right but let me explain. I have created a interceptor that I use on all my ejbs which require authorization to use, this interceptor is called every time a method is called.

See here the code:

@Secure
@Interceptor
public class SecurityInterceptor {

    @EJB
    private SessionManager sessionManager;

    @AroundInvoke
    private Object securityCheck(InvocationContext ctx) throws Exception {
        System.out.println("hello");
        List<UserGroup> allowedRoles = (List<UserGroup>) ctx.getContextData().get("rolesAllowed");
        sessionManager.isAuthorized(allowedRoles);
        return ctx.proceed();
    }
}

Now I don't want in my Named Bean to surround the body of every method that uses one of these secured beans with a try and catch block, like this:

public List<Contracts> getContracts() {
    List<Contracts> contracts = new ArrayList<>();
    try {
        contracts = contractEntityManager.getAll();
    } catch (EJBTransactionRolledbackException e) {
        Throwable throwable = ExceptionUtils.getRootCause(e);
        if (throwable instanceof NotAuthenticatedException) {
            System.out.println("Not Authenticated");
        }
        else if (throwable instanceof UnAuthorizedException) {
            System.out.println("Not Authorized");
        }
    }
    return contracts;
}

So is there some way to globally catch a runtime exception and the redirect the user to the login page if he is unauthenticated and to a error page when he is unauthorized.

Maybe my design is just generally bad and I would need to complety rethink this idea. Please let me know.

Thank you

Answer 1

So, in the end, it is the in the web tier that you want to catch the exceptions. This is easy:

• If you are only on servlets, specify the error-page element in web.xml for each exception you wish to handle, eg as follows:

   <error-page> <exception-type>fully.quallified.NotAuthenticatedException</exception-type> <location>/where/to/redirect/eg/login</location> </error-page>

  You declare the exception you want to handle globally and the URL you want to handle it, it may be a servlet, a JSP or any other resource.

• JAX-RS offers a similar mechanism with the javax.ws.rs.ext.ExceptionMapper :

   @Provider public class NotAuthenticatedExceptionMapper implements ExceptionMapper<NotAuthenticatedException> { ... }