ven jovovich

Thanks a lot for your time and suggestions.

Regard,
Ven.

Hi everyone,
I need some information to take a decision which matters a lot to me. I know this is a
bit lengthy and I request you to read through it.
Currently I am working as an application developer with the Java language and
frameworks like Spring and Hibernate. Sometimes I do have to write custom frameworks
for specific purposes. I like to design application / algorithms and frameworks more than
just learning an existing framework and using it. Yes, I do use and love Vim as my primary
editor and I love to code.
Recently my boss has offered me a position in which I will have to work with big data.
Below are the prerequisite skills for for the position:
hands-on experience in Core Java, Unix/Linux, SQL and good analytical skills to grasp
and apply the concepts in Hadoop.

- Mandatory: Core java, Unix / Linux, SQL
- Good to have: Python, Spring / .Net / C++
- Highly desirable: Linux administration, Big Data Skills (Hadoop, HBase, Cassandra,
Spark, Splunk, Marklogic, MongoDB etc)

I have an intermediate understanding of SQL, Python, Unix/Linux. From a quick
search I have found that big data is about huge volumes of data and Hadoop is a framework
for handling such data.
Having read what I enjoy doing, do you guys think I will be comfortable with
big data? Will I get to design some framework / algorithm or write code from
scratch? Is big data only about data analysis and making sense of the data to a business?

Any light in this matter would be of immense help.

Regards,
Ven.

Noted. Thanks.

Thanks Surendra, but would you suggest starting with one before the other?

Just to make things a little more interesting, check out what "intern()" does. ;)

Regards,
Ven.

Hi all,
My manager has assigned me to a project which involves both Spring
and Hibernate. I know absolutely nothing of either. Please suggest which one to
start with. I am really confused, I don't even quite know if one of these is loosely
related or dependent on the other.
Currently I am familiar with core Java, Servlets, JSP and Oracle SQL, PL/SQL.
Thanks in advance.

Regards,
Ven.

Thanks Winston, lots to learn here.

Thanks Matthew and Winston.

@Winston: what Matthew says is what I meant It's not just the documentation, even the code is... not wrong... just bad design. I agree that documentation sucks and my sincere respect to that programmer, maybe I would have made the same mistake(s).
Neither am I paid for my command over the English lang.

Regards,
Ven.

Hi all,
Can there be any situation where one would invoke a static method on an instance?
I thought that there are no advantages of calling a static method on an instance as the object handle gets
replaced with the class name during compilation. I came across some propietary code (which I can't
put up here) where we are doing just this... and I can't understand why, even the documentaion states
that we call this static "method on an instance of the class".

Regards,
Ven.

Thanks a lot guys
Although I read the doc, somehow I had overlooked @throws... damn...

Resolved.

Regards,
Ven.

Hi all,
I understand that there are two ways to get a java.lang.reflect.Field object:
1. getDeclaredFields() - returns Field[]
2. getField("field_name") - returns a Field for "field_name" ONLY IF field_name is
public in it's class.

What I am not getting is point number 2. Why can we only get a Field object of
a field that is public? We can anyways get an array of all declared fields, so
this has got nothing to do with security etc...

Looking forward to your response.

Regards,
Ven.

Thanks Ulf,

A thousand apologies.... somehow I managed to interpret "Class c = boolean.class;" as "boolean b; Class c = b.class;".

Regards,
Ven.

Hi all,
I found the below mentioned statement here: http://docs.oracle.com/javase/tutorial/reflect/class/classNew.html
Class c = boolean.class; // correct

Somehow it doesn't compile on my machine (JDK 1.6).
My code:
import java.util.*; class A { public static void main(String[] args) { int i; boolean b; Class c = b.class; Class c2 = i.class; // System.out.println(java.lang.String.class); // System.out.println("abc".class()); } }
Error:
A.java:7: cannot find symbol symbol : class b location: class A Class c = b.class; ^ A.java:8: cannot find symbol symbol : class i location: class A Class c2 = i.class; ^ 2 errors shell returned 1
Please help.

Regards,
Ven.

Paul Clapham wrote:Yes, it's certainly possible that all of your application threads could be waiting. Did you consider that to be a potential problem? If so, why?

Thanks Paul. This was just a toy program I was trying... but yes it is a problem because my program has not completed executing, yet it is doing nothing, on the contrary it is may have acquired some locks (sleeping). Sounds like deadlock-for-a-short-interval-of-time. It would be nice if you would add your views to this.

Jeff Verdegan wrote:
We don't sleep to give other threads a chance to run. We don't do anything to give other threads a chance to run, except maybe set threads' priorities to possibly give some desired shape to the distribution (although even that does not have well defined results). The JVM takes care of scheduling for us. The only reason you would sleep is if you want your current thread to stop working for some time, for its own reasons.

Thanks Jeff. Agreed 100%. This was just a toy program that I was experimenting with and had spared no thoughts on design, all I wanted (blindly) was to give the producer a chance to run. Surely I will keep these things in mind from now on.

Regards,
Ven.

Thanks a lot Jeff.

This doesn't make sense. The producer shouldn't care what the consumers are doing. That's the reason we decouple them and make it multithreaded--producing and consuming are independent tasks.

Excellent point you got there... maybe I was thinking too much about threads and lost sight of the basics....

(is this a state when the JVM executes no thread(s)?).

No clue what you're saying here.

What I meant was, the producer thread is sleeping (or waiting) for the consumer threads to complete and the consumer threads are in turn sleeping, so the JVM is not executing any thread(s) except keeping track of how long the consumer threads have slept, so is the JVM in a state in which it executes no threads?

Also, why are your consumers sleeping in the first place?

I wanted to make sure that the producer would have a chance to run but it won't.

Regards,
Ven.