Gary Marshall

I'm reading the description of the content of your course and what I see is this: the course teaches you how to create a Spring / REST API that then is a product that is available for consumption by a client application. Is this correct? I do not see this as a video course that teaches a developer how to create applications using the Spring framework with REST. Can you please clarify?

Thank you
Gary

All:

Ok, I'm a linux / Fedora noob, and I wholeheartedly admit it. I've been told a few times by linux seniors about not using Root to do stuff with and I've been behaving myself, but yesterday I got bit.

I downloaded Tomcat 7 on my System 76 machine that has Fedora 19 installed. The tar.gz was placed in the Downloads folder. I found a good website that walked me through the installation process. Using Files I right-clicked the tar.gz and click "move to": and selected the "/usr/share" directory and I got the "Error opening file '/usr/share/apache-tomcat-7.0.42.tar.gz': Permission denied" message indicating I did not have the privilege to do this, which kinda sucks, since it is my own personal machine. I lord over this thing and to tell me I can't do something is...welll blasphemous. As an experienced windows user I'm getting really bent up at this OS which keeps refusing to do silly simple things I want done within Files, like I do when I use file explorer in windows like, for example, move a file from one folder to another.

So, in order to get around this nonsense I did a CHMOD 777 on the /usr folder. Yeah I know what your thinking. "You dumb a**!" And your right. As I stated I'm a noob and my ignorance bit me. See by doing the CHMOD 777 on the /usr folder I hosed up the sudo utility and it rendered my password for my root user useless, which meant I could no longer do a lot of stuff, which meant my OS was also practically useless.

OK, so noob mistake. I copied selected folders of data off to an external hard drive and reinstalled the OS. I had my data on a different drive than the fedora install but I see that I have to install all of the software that I use ie: java, tomcat, mysql, intelliJ, etc, etc.

So I tell you all this in order to ask this question: Is this the way it works with linux / Fedora? If I screw up and render the OS useless to the point that I have to reinstall the OS does that mean I will also have to reinstall all of the software I use? Is there a way to avoid reinstall all of the software one uses when a reinstalll of the OS is required?

Thank you for your time.
Gary

All:

Greetings and salutations, and a happy new year to all!

So I have become fed up with my windows 4g laptop and I'm ready to buy my next laptop. My next laptop will have the goodies - 16g, perhaps 32g of memory, a huge SSD drive and an expensive Intel chip.

I am becoming increasingly worn out by and disenchanted with the Windows OS. I'm thinking that its time for me to dig in and learn the linux OS. I would like to get to the point where I can get around the system and do simple and not so simple tasks and be as productive as I am in the Windows environment. My simple question to you fine techies out there is this: What would you recommend as a good linux OS? Would you recommend Ubuntu, Red Hat, Fidora (are these two the same?), CentOS?

What would your recommendations be given a brand new machine configured with the good hardware? Oh and by the way, I only have about, oh say four months of experience of application development on a MAC machine. I'd thought I'd throw that into the mix.

Thank you all for your time and suggestions.
Gary

Thank your Mr. Bear, for your suggestion concerning the Mac.

As I mentioned, among many other things, I am learning Linux. My question concerning the Mac: will I be able to learn the commands as well as how to administer a Linux OS on a MAC just as well as I could if I were to be running a true Linux system on some other (non Mac) machine?

Thank you again, sir
Gary

All:

I am now working for a company that has me learning things by the hour. Great! Seriously, I like it. I find that in my quest for all the technical knowledge I need to accumulate I am spending time at home during the evening hours working on things.

This is all well and good except for the fact that my 4GB Windows Vista machine is now cramping up on me as I get deep into the software I am playing with. So I'm thinking about buying a new laptop that has the horsepower and memory that I need to do the work that I need to do. And, by the way I can be a real little piggy when I'm at work. I will have JBoss open, Eclipse AND NetBeans open, one or two command line windows (or terminal sessions), not to mention at least one FireFox browser session running. I'll be starting and stopping servers, writing and saving program code, googling all around the world for solutions to problems I'm having or answers to questions I have, and who knows what else. Of course, while all this is going on, I'll need to view a Youtube video on installing something or other.

So anyway, I would like to get a laptop because I want the portability. Obviously this laptop has to have the maximum memory it can hold and I would like it to have either a 750GB or 1TB hard drive. And I want a screaming processor. I want a laptop that will not cramp up whatever the load I put on it.

I've been considering several Windows type laptops that I would just wipe the hard drive and load up Red Hat Fedora (I'm learning that also). I've found a HP machine that comes with what appears to be a good Intel processor and 16 GB memory and 1TB hard drive. But I also found a MAC Book Pro that also has 16GB memory and a speedy 750GB hybrid SSD drive that costs twice as much as the windows machines. Hmm....Mac....

Any suggestions?
Thank you for your time and suggestions.
Gary

Got it. I understand. Thank you for your time.
Gary

All:
Snippet of code taken from one of the questions contained in the K&B SCJP6 Study Guide Master Exam:
public class Numbers { public Numbers(int...nums){} public Numbers negate(){ Numbers neg = new Numbers(); // Line 1: NO COMPILER ERROR? return neg; } public void show(){} public static void main(String...args){ new Numbers(1,3,-5).negate().show(); } }

I understand, according to the same book I referred to, that if I coded a constructor in my class then the compiler will not provide a no-arg constructor for me. OK, quick question: Can someone please tell me why the line of code at "Line 1" does not cause a compiler error?
Thank you for your time
Gary

All:

I have the paperback version of the K&B SCJP 5 Study Guide and have I have just completed the Master Exam found on the disk that comes with the book. Now I would like to review my answers to the questions using the answer guide that is provided but I do not see any button anywhere that allows me to do this. The only item I can find now is a widow that includes a bar graph illustrating my results. Does anybody here know how I can bring up the "Exam Review" window for the exam just completed?

Also I'm wondering if the questions on this master exam are supposed to be more difficult or as difficult as the real exam. Don't know if anybody can legally answer this question or not but I thought I'd through it out there in the chance it can be answered.

Thanks to all for your assistance
Gary

All:

This code from the JavaBeat SCJP1.6 bank of questions focusing on NavigableSet:
public class Ques08{ public static void main(String[] args) { Rank rank1 = new Rank(1); Rank rank2 = new Rank(2); Rank rank3 = new Rank(3); Rank rank4 = new Rank(4); Rank rank5 = new Rank(5); NavigableSet<Rank> ranks = new TreeSet<Rank>(); ranks.add(rank2); ranks.add(rank3); ranks.add(rank1); ranks.add(rank5); ranks.add(rank4); for (Rank rank: ranks){ System.out.println(rank); //sysprint 1 } ranks.pollFirst(); ranks.pollLast(); System.out.println(); System.out.println(ranks.pollLast().toString()); //sysprint 2 } } class Rank implements Comparable<Rank>{ private int rank; public Rank(int rank){ this.rank = rank; } @Override public int compareTo(Rank second) { return -1; } public String toString(){ return rank + ""; } }
The result of this run is "3" and I understand this result is because by the time we reach line "sysprint 2", "3" will be the last entry in the ranks TreeSet. What is confounding me is the sorting of the elements in the TreeSet. I am told that the compareTo() method in the Rank class "tries to sort the elements in descending order". Well, what displays after the execution of the "sysprint 1" line of code is:

4
5
1
3
2

Quite possibly the answer to my question is staring me in the face and I just don't see it. Can anybody please explain to me why, given the configured compareTo() method in the Rank class, the order of the elements in the ranks treeset is not in true descending order? Why am I wrong when I am expecting the elements in the TreeSet to look like:

5
4
3
2
1

??
Thank you for your time.
Gary

Sorry.

This question came from the ePractice: Java Standard Edition 6 Programmer Certified Professional Exam from Oracle.

OOPS... Looks like I gotta get better glasses...

Thank you for your time.
Gary

All:
Consider this code:
public class Lockdown implements Runnable { public static void main(String[] args) { new Thread(new Lockdown()).start(); new Thread(new Lockdown()).start(); } public void run() { locked(Thread.currentThread().getId()); } synchronized void locked(long id) { System.out.print(id + "a "); System.out.print(id + "b "); } }
A given run of this code can produce the results "11a 10a 11b 10b".

OK. I understand that the locked() method is synchronized so that only one thread at a time can use it. I also see that the run() method is NOT synchronized. I don't understand how this result is possible because while the run() method is NOT synchronized the locked() method is. So lets see, one of the threads starts and gets into the run() method first and then invokes the locked() method, thereby getting the lock on the object. That is supposed to prevent the other thread from executing the same method at the same time, correct? Which is what we want because both threads are using the same runnable. But, obviously that is not happening here. Could the JVM be swapping out the two threads and that's why I am getting this kind of result occasionally? If not, please help me understand how this result occurs.

Thanks to all for your time and consultation.
Gary

Thank you all for your time in responding.

I'm so terribly new at the OSGI thing that its possible I did not understand what the PM was telling me in our first interview. A week ago I asked him again, via email, about using J2EE in the development work - which, I now recall is the development of a "framework" for the modular applications, not the applications themselves. The app development could possibly happen in the future. Here is a snippet of his email response to me:

"....... I suspect we will be writing some J2EE web apps but right now we are testing that under OSGI Pax-Wicket which departs from the normal J2EE model of doing web app deployment...."

So there you go. That's what he meant by not using any J2EE frameworks, I guess.

@Jignesh Patel: What is concerning me is NOT learning something new but rather possibly silo-ing myself into a technology that may or may not be in demand in two years. However thanks to the news from Mr. Knoerschild concerning Java 8 and its relation to OSGI, perhaps I don't need to be concerned about marketability.

Thanks again
Gary

Talk about timing.

I am being presented a job opportunity where I would learn and develop using OSGI. The project is being defined to me as a two-year long project, with, thus far, "possible" additional opportunities; the additional work mostly dependent upon the success of this two-year project.

Now I am a complete newbie at OSGI. And while I always welcome the opportunity to learn new technologies, I have to admit I have a little bit of fear over this one. That is because I'm not sure where this OSGI thing is going.

See, I had not heard of OSGI until my first interview with this project manager a couple of weeks ago. The project manager stated to me that the project involves OSGI, JBoss and Postgres (sp?). He wanted me to know further that there are no Java EE frameworks involved here. As I stated, this is a two year long project. So my fear is that if I go to work on this project for two years and learn all there is to know about this platform, then if I find that I have to put myself back on the job market, will my skill set still be marketable? For two years I will not be working with Java EE, or Spring or Struts, or JPA and Hibernate, the technologies that most java shops are looking for on a job candidate's resume. Will I be able to find another decent java developer position if I work on OSGI for two years? This is the question that keeps nagging me concerning this opportunity.

I certainly welcome and thank you all for your professional perspective concerning my opportunity and my concern.
Thank you
Gary

oh jeez. That's right, I forgot that one.
Thank you Henry