Oracle 1z0-816 Exam Dumps

Question 6 of 40

Given:

Which one is correct?

An IllegalThreadStateException is thrown at run time.

Three threads are created.

The compilation fails.

Four threads are created.

Correct Answer: A

An IllegalThreadStateException is thrown at runtime. In the given code, `t1.start();` is called twice. According to the Java documentation, starting a thread that has already been started is not allowed and will result in an IllegalThreadStateException.

Question 7 of 40

Examine these module declarations:

Which two statements are correct? (Choose two.)

The ServiceProvider module is the only module that, at run time, can provide the com.example.api API.

The placement of the com.example.api API in a separate module, ServiceAPI, makes it easy to install multiple provider modules.

The Consumer module should require the ServiceProvider module.

The ServiceProvider module should export the com.myimpl package.

The ServiceProvider module does not know the identity of a module (such as Consumer) that uses the com.example.api API.

Correct Answer: B, E

The placement of the com.example.api API in a separate module, ServiceAPI, indeed makes it easier to install multiple provider modules. By having the API in its own module, different modules can implement the API without modifying the API module itself, thus allowing for flexibility and easy swapping of implementations. The ServiceProvider module, on the other hand, does not need to know the identity of any modules that use the com.example.api API. This separation of concerns adheres to the principle of module decoupling, where the provider does not need to be aware of the consumers of the service.

Question 8 of 40

Assume ds is a DataSource and the EMP table is defined appropriately.

What does executing this code fragment do?

inserts two rows (101, 'SMITH', 'HR') and (102, 'JONES', NULL)

inserts two rows (101, 'SMITH', 'HR') and (102, 'JONES', 'HR')

inserts one row (101, 'SMITH', 'HR')

throws a SQLException

Correct Answer: B

The code uses a PreparedStatement to insert rows into the EMP table. Initially, it sets the values (101, 'SMITH', 'HR') and executes the update, inserting the row. After that, it resets some of the parameter values and executes the update again. The second set of values are (102, 'JONES', 'HR') because only the second parameter is changed to 'JONES', while the third parameter ('HR') remains unchanged from the previous setting. Therefore, two rows (101, 'SMITH', 'HR') and (102, 'JONES', 'HR') are inserted.

Question 9 of 40

Given:

var fruits = List.of(“apple”, “orange”, “banana”, “lemon”);

You want to examine the first element that contains the character n.

Which statement will accomplish this?

String result = fruits.stream().filter(f −> f.contains(“n”)).findAny();

fruits.stream().filter(f −> f.contains(“n”)).forEachOrdered(System.out::print);

Optional result = fruits.stream().filter(f −> f.contains(“n”)).findFirst ();

Optional result = fruits.stream().anyMatch(f −> f.contains(“n”));

Correct Answer: C

To examine the first element that contains the character 'n', you should use the stream method 'findFirst()' after filtering elements that contain 'n'. This returns an Optional containing the first occurrence that matches the condition or an empty Optional if no such element is found.

Question 10 of 40

Given:

What is required to make the Foo class thread safe?

No change is required.

Make the declaration of lock static.

Replace the lock constructor call with new ReentrantLock (true).

Move the declaration of lock inside the foo method.

Correct Answer: A

The given Foo class is already thread-safe because it uses a ReentrantLock to ensure that only one thread can enter the critical section defined by the foo method at a time. The lock is acquired before accessing the shared resource (state) and is properly released in the finally block, ensuring that the lock is released even if an exception is thrown. All necessary precautions for thread safety are already in place.