Java and Spring Framework Online Test

A company is designing the class hierarchy for various cache implementations:

public class Cache {}

public class DiskCache extends Cache {}

public class MemoryCache extends Cache {}

public class OptimizedDiskCache extends DiskCache {}

Select all the answers that will result in a runtime exception.

(Select all acceptable answers.)

Consider the following Spring bean:

@Component
public class TaskExecutor {

    @Value("${thread.count:10}")
    private int threadCount;
    @Value("worker.thread.name")
    private String threadNameTemplate;
    private AtomicInteger counter = new AtomicInteger();
    private ExecutorService executorService;

    @PostConstruct
    public void init() {
        ThreadFactory threadFactory = (runnable) -> new Thread(threadNameTemplate + counter.incrementAndGet());
        executorService = Executors.newFixedThreadPool(threadCount, threadFactory);
    }
}

Select the statements that are correct.

(Select all acceptable answers.)

Refactor the AlertService and MapAlertDAO classes:

• Create a new package-private interface, named AlertDAO, that contains the same methods as MapAlertDAO.
• MapAlertDAO should implement the AlertDAO interface.
• AlertService should have a constructor that accepts AlertDAO.
• The raiseAlert and getAlertTime methods should use the object passed through the constructor.