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Robert Lippens

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since Jun 23, 2013
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Recent posts by Robert Lippens

Hi guys,

Ecstatic about getting my OCAJP certification yesterday, I updated my resume online and woke up to a missed call from a recruiter. Things looking better already! I called them back, no go on the job, they want (2+ years experience). Of course, this has forever been the problem, experience, experience, experience. I didn't go to school for Computer Science, I haven't worked an internship, and now I want to break into the field as a Java Developer. The cert is helping me get noticed, but it's still boiling down to experience. How can I best get experience without having a job as a programmer? Undersell myself as a freelancer for the time being? I need something to put on a resume that says "I know what I'm doing, see?"

Another question: the job I was contacted for did not simply say they wanted a guy with Java experience, but a whole host of other languages (JavaScript/JQuery, HTML, CSS, HTTP, REST, SOAP, SOA, SQL, etc.) Does anyone actually "know" all of these things when they are hired? I've worked with some of these before (as in: dabbled) but I have a hard time envisioning most candidates know much of anymore than a handful of these (unless they've been in the industry for years). I guess they're just posting up the ideal candidate, in case one exists? Help a newbie navigate this job market that has proven his bane for the last 2 years!
5 years ago

-Amit- Sharma wrote:Hey congrats .

I am also planning for the same .

would you please suggest me apart from Finegan and Liguori and Enthuware what are other resorces i should go for ?

Thanks .

These were the only two I used, other than that, just play around with the code you see in the practice exams. Try all sorts of weird scenarios - what happens if you change this, or that variable. It will give you a good understanding of how things work.
5 years ago
After 4 months of studying, I took the exam this morning and just found out I passed! Scored a comfortable 85%, not as high as I had hoped but it doesn't matter now! Enthuware mock exams helped SO much, as did the book by Finegan and Liguori. Just really happy and wanted to share it with everyone
5 years ago
The issue is the architecture. Java SE 6 will only run on 64-bit architectures for Intel mac's and he has a 32-bit (found this out via his system specs/apple website). He could have the latest OS X version but, due to his architecture, would not be able to upgrade to SE 6.
6 years ago
Hi guys,

I am trying to send my friend a program I made in Java.

His computer runs java version 1.5.0_30 using the Java(TM) 2 Runtime Environment. So, in my Eclipse project, I went to properties, and then java compiler, where I changed the default compliance to J2SE-1.5, as well as changing my system library in the build path to JRE System Library [J2SE-1.5]. I thought this would make the program run on his system but when he attempts to run my program he gets the error:

Exception in thread "main" java.lang.UnsupportedClassVersionError: Bad version number in .class file

The rest of the error messages do not relate to any of my class files, and the stacktrace just links back to and sun.misc files.

Going back to the project properties, it tells me that every execution environment I can select requires Java SE 6. My friend runs Java SE 5 on a 32 bit architecture Intel mac and cannot update to SE 6(for some reason Apple found it prudent to not support an up-to-date version of Java for 32 bit intel architectures.) My computer is a 64 bit architecture (Intel Mac) and I can't seem to get SE 5 on it.

My other friends have no problem opening the jar, so I know it is functioning properly. I was wondering if there was any way I could get it to run on his older system? I've been beating my head against this for an hour now with no success.

6 years ago
So let me see if I got this one straight.

At: System.out.println(b.h + " " + b.getH());

The inner method statement is evaluated first, and it will first activate Beta's println statement inside of the getH method. So the first thing printed will be "Beta 44".

Then, the rest of the values inside of the main method print statement will be evaluated: b.h = 4, b.getH() returns 44 so the next line will be 4 44.

The same will occur for the bottom method, yielding

Beta 44
44 44
6 years ago
I am making good progress using Enthuware's test simulation software (first test was a 52%, second 81%, third 72%). However, I don't seem to get any of the answers they have here in this code segment. Fortunately I guessed the right one, but I have no idea why the answer is what it is.

I went through it as follows: the first print statement will access Baap's h variable, and thus print "4", then b.getH(); will read Beta's getH method and give "Beta 44".

Then, similarly, bb will give b = "44" and getH will again be Beta's getH method and print "Beta 44". There was no constructor given, nor any static statements to worry about, so I figured this was the end of what should appear. I don't think the return statement in either getH method affects anything either. Thus my expected answer was:

4 Beta 44
44 Beta 44

However, the answer is apparently:

Beta 44
4 44
Beta 44
44 44

So... what am I missing here??
6 years ago
Thanks for further explanation guys, it has satisfied my brain. Yeah, some of it I can get bogged down in, but I tend to forget things unless I can explain them to myself. If it's just some arbitrary fact (well, eventually it is an arbitrary fact/axiom) I find it difficult to keep in my head. If it has a reason, then I can reason about it later in case I forget the answer.

For instance, I just learned if I have a class with a constructor that throws an exception, if I subclass this class, the subclass constructor has to throw an exception that is a SUPERclass of the constructor's exception (the opposite of how the method subclassing exception rules work). I suppose I could have just remembered this fact, but having been able to explain it to myself now, I am sure I won't forget it as easily as without!

I haven't signed up for the OCAJ7 exam yet, so it's best I plan for the long run here
6 years ago
Thanks for the link. Indeed it sounds like it's just something that has to be done.

Any local variable, formal parameter, or exception parameter used but not declared in an inner class must be declared final.

is their exact wording! I think it's just my math brain demanding proofs for everything I read, I don't like the language just telling me what to do without knowing why
6 years ago
Congrats! Those enthuware exams are obliterating me... guess they're worth it though! Going to go for OCPJP soon I guess?
6 years ago
None now! I see what's going on after your explanation.

To test it out, I made in my main, something like Worker joe = getWorker(12);

This then ran the method getWorker, inside of which did exactly what you said it would. I could call joe.perform_work(); and it would print out whatever number I assigned joe in the method, which sort of acts like a ... constructor?

One more question about this.... why must my method declaration require a final parameter? Apparently it cannot be seen accessed from the perform_work method... but it lies within the method body?
6 years ago
For your second question check out:

Apparently, float can hold larger numbers than long, but there are errors introduced because of the fact that it rounds.
6 years ago
I ran through Enthuware's practice Inheritance test, since that seems to be where I am struggling the most (along with explicit casting). Sufficient to say, I didn't do too well.

I am particularly stuck on this example of anonymous inner class/nested classes/local classes.

From what I understood an anonymous inner class looked something like this:

where you instantiate an implementation of the Interface via something like:

Now, they had the following, which I cannot follow whatsoever.

This class seems to lack the "new" keyword (aside from the return statement... which I also don't understand.) Are the first two lines equivalent to Worker getWorker = new Worker(final int i) { //implementation of interface methods here } ?

I've never seen an anonymous class example like this before, so it's throwing me for a loop!
6 years ago
Ah oops, you answered it for me - for some reason I was wondering how to access changeIt(str) but it doesn't return anything so there is nothing to access again later in the code (I could call the method again over and over though)! If changeIt(str) had had a return type of String then I would have to make a call in main like

String changed = changeIt(str);

so if I had ever wanted to refer to that new String object I made in changeIt, I could just use the variable changed, which points to the String object. I thought I had some object made with no reference to it, but all I did was print something to the screen. Too many hours of studying polymorphisms earlier, I guess...

I guess I just needed to sleep on it and let my brain process things. Thanks!
6 years ago
Ah yeah, so it doesn't get collected until the actual class is no longer loaded. However, I still will never be able to access it again, correct? If there is no active reference to it, I have no way of getting back to it, even though it won't be deleted? It just sits there, floating in the endless expanse of 1's and 0's, forever lost?
6 years ago