Jeanne Boyarsky

I'm now "double certified". I've passed all three of the part 1 (1Z0-815), part 2 (1Z0-816) and upgrade (1Z0-817).

My blog posts on these

part 1 (1Z0-815)

part 2 (1Z0-816)

upgrade (1Z0-817)

should I take the 816 or 817

what does it mean to be Java 11 certified

Congratulations Ivana!

Also, don't worry about this on the real exam. The real exam tells you how many answers are correct. If you got this question and it said "choose 2" you'd know right away!

I got this question by email. Posting here since I prefer to answer book questions in the forum.

On Page 489, the example says that the Files.walk() method looks at the input parameter's subdirectories and prints files there too.

But on Question 17, I was told the answer was G instead of EFG. Why is this? What about the test question makes it different from the example?

E is "It prints all .java files in the /animals directory tree"
F is "It prints all .java files in the /animals/cute directory tree"
G is "It prints all .java files in the root directory tree"

E and F are more specific than G. So yes, you could argue that they are true. It's an interpretation of English thing. We took it as "only prints". I'll make a note for the Java 11 book so we clarify this.

Luciano,
It would count as 0 points. The good news is that the "review" screen will warn you that you didn't supply enough answers. (This is the same screen used when you mark questions for review.) Similarly, if you try to select 3 answers and only 2 are allowed, the software will prompt you that you need to uncheck one before choosing another.

So it's hard to accidentally chose the wrong number of answers. Which is good. You can worry about focusing on getting the *right* answers during the exam without worrying about giving to few or too many.

Brecht Geeraerts wrote:Hi all,

I have a question related to the aforementioned book also in Chapter 7 Concurrency (but on page 337).

As you can see in the image, the following is stated: "... the ExecutorSercive interface does not implement AutoCloseable...". Since both are interfaces and one interface does not implement another interface - but rather extends - shouldn't this be changed?

It is not (yet) mentioned on the errata list for the book.

Good catch! I've added it to the errata list and credited you. We will be sure to fix this in our 1Z0-816 book!

I took (and passed) 1Z0-816 today. That's the first step in starting book 2!

I blogged a bit about it.

Jen,
No, you are not allowed to use the JavaDoc (or any other reference material.)  Anything you need to know needs to be in your head.

If you dont' already have a study guide, I recommend buying one. That distills the information you need to learn. Granted it is still a lot. But at least you won't waste time and mental space on APIs known not to be on the exam.

Almost never. There might be one or two questions. (Because there are some questions that there are only so many ways to ask.). I remember when I took the OCA 8 and saw a question on the exam that matched almost exactly one I wrote. But that's rare.

You need to understand the concepts. Memorizing questions will not help. Luckily, the questions you encounter in study guides are often harder than the ones on the exam.

This is a Java 8 cert book. We assume you are using Java 8. We didn't test with Java 7 and I wouldn't expect it to work. So the first thing to do is change your classpath to use Java 8.

java -cp "c:\Program Files (x86)\Java\jdk1.7.0_55\db\lib\derby.jar;."

Tony Esposito wrote:Hi Jeanne,
Any new "news" on this topic?
Thanks.

Anthony (Tony) Esposito

Sorry. I was unexpectedly* unavailable this week. I'll reply today or tomorrow from the email account.

* when it is expectedly, I arrange for coverage

The last thing you rmain method does is call networkClientModule = new NetworkClientModule();. This is the code that winds up creating the NetworkClientModule.oServer.

You ahve two choices:

Add a check for whether NetworkClientModule.oServer is null before calling it

Move the initialize code earlier in your program so actionPerformed() can't run before that happens

Comparing primitives uses ==
if (num1 == num 2) { }

Pablo,
Good question.

Consider this code:
public void test() {   Hopper h = new Hopper();   h.hop(); }

This is good. The hop[() method doesn't declare an exception so test() doesn't need to either. Now we have an example that doesn't compile:

public void test() {   Bunny b = new Bunny();   b.hop();  // does not compile }

b.hop() declares a checked exception. But test() does not handle or declare it so that's a compiler error. Good so far? Now think about this one:

public void test(Hopper h) {   h.hop(); }


If the caller calls it with test(new Hopper()), all would be fine. But if the caller calls it with test(new Bunny()), we have a problem. The checked exception has nowhere to go.

Since the type of Hopper could be any subclass, this situation presents the compiler with a problem. Java solves that problem by not allowing you (the developer) to add checked exceptions to a method signature that you override. Since Java does not permit this, it knows that all subclasses of Hopper will not throw a checked exception from hop() so the test(Hopper h) method is happy.

Now off I go: Hop. Hop. Hop.

Brecht Geeraerts wrote:@Jeanne: I'm not doubting that the book will exist. In fact, I'm very eager to get my hands on it.

I know. I was teasing Paul. (Who also knows it will exist)

Brecht Geeraerts wrote: The previous books (OCA, OCP) are very good.

Thanks!