Sybex Practice Tests 11, possible errata, chapter 7, Q 57 and Q 58 and Q 59

[Mike Gualeni]

Hi there,

Question 57 on page 258 asks what needs to be included in the module-info for it to be a service provider:

Question 56:
You have the following interface in a module named animal.insect.api.

package animal.insect.api.bugs;

public interface Bug {
    int crawl();
}

Question 57:
And you have the following class in a module named animal.insect.impl and the service provider interface module from question 56 (from above). What needs to be included in the module-info for it to be a service provider? (Choose two.)

package animal.insect.impl;

import animal.insect.api.bugs.Bug;

public class Worm implements Bug {
    @Override
    public int crawl() {
        return 1;
    }
}

A. requires animal.insect.api.bugs;
B. requires animal.insect.lookup;
C. requires animal.printer;
D. provides animal.insect.impl.Worm;
E. provides animal.insect.api.bugs.Bug with animal.insect.impl.Worm;
F. provides animal.insect.impl.Worm with animal.insect.api.bugs.Bug;

And the answer on page 514 is:

A, E. This module is a service provider. It needs a requires directive for the service provider interface, which is option A. It also needs a provides directive which specifies both the interface and implementation. Option E has both in the correct order.

But A is not right because the directive is:

requires <module> not requires <package>

And question 58 also:

Suppose you have the following class in a module named animal.insect.lookup, the service provider interface from question 56 (from above), and the service provider from question 57. What needs to be included in the module-info file besides an exports directive for it to be a service locator? (Choose two.)

package animal.insect.lookup;

import animal.insect.api.bugs.Bug;
import java.util.List;
import java.util.ServiceLoader;
import java.util.stream.Collectors;

public class InsectFinder {
    public static List<Bug> findAllBugs() {
        return ServiceLoader.load(Bug.class)
            .stream()
            .map(ServiceLoader.Provider::get)
            .collect(Collectors.toList());
    }
}

A. provides animal.insect.lookup;
B. provides animal.insect.lookup.InsectFinder;
C. requires animal.insect.api.bugs;
D. requires animal.insect.api.Bug;
E. uses animal.insect.api.bugs;
F. uses animal.insect.api.bugs.Bug;

And the answer on page 514 is:

C,F. This module is a service locator. It needs three directives: exports, requires, and uses. The requires directive specifies the module it depends on, which is option C. The uses directive specifies the service provider interface it references, which is option F.

Answer C is not right because like on question 58 requires directive needs a module not a package! And animal.insect.api.bugs is a package. In question 56 they name the interface module animal.insect.api not animal.insect.api.bugs

And the same problem is on question 59, with answer A,B, but A is not right because in A in the requires directive the package animal.insect.api.bugs is mentioned but it should be the module animal.insect.api!

[Jeanne Boyarsky]

Doh! You are correct. Added to the errata.

[M Janssen]

Ch 7 #57 has been added twice to the list on https://www.selikoff.net/ocp11-pt/.
I think Ch 7 #58 and #59 should be added, and Ch 7 #57 only once.

[Jeanne Boyarsky]

Added 58 to errata. 59 is on our "list of things to check if they should be clarified"