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Posted on 28 October 2009 by Srinivas Nelakuditi

Upgrade or obsolete ?

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Neal Ford Technical Architect of ThoughtWorks spoke about the importance of upgrading your skills in the current scenario and stay relevant to avoid future shocks. He gave an example of how the role of blacksmith has been replaced or rendered useless with the advent of technology changes.

I can clearly relate to Ford and I have seen a number of instances where a developer thought that languages like C and C++ are going to be the bread and butter for ever. But one fine morning saw their entire code base to be moved to a new language or platform which they are not knowledgeable.

A person specializing in only one area may find his prospects good for a short while but with the quick change of technologies & outsourcing of jobs, It is always better to have multiple skills and have a broader perspective towards technologies.

Trends to watch are web development, mobile development,  Social networking arena , Cloud Computing & new functional languages.

What  you can do to make your career smoother:

1. Upgrade and keep upgrading.

2. Do not stick to one technology or framework, experiment with new stuff day after day.

3. Do not assume you are an expert in one technology, language or framework. Keep learning new ideas.

4.Take certifications in a new technology when ever possible.

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Posted on 05 March 2009 by Srinivas Nelakuditi

Amazon SimpleDB Web Service with Simple JPA API, Typica API and Java

aws logoIn this article I will explain how to use Amazon SimpleDB web service using Java Persistence API (SimpleJPA) + Typica API

Read the previous blog, In which we were using Typica API only. Compare the StudentDAOImpl in this project and the previous project where we were using Typica API only.

Using SimpleJPA + Typica API simplified the code and it is easy to develop complex applications.

Read my previous blog post about using Amazon SImpleDB using Typica API Only.

What are we going to do in this tutorial

I am going to create a student object. After creating the student object, we will use Amazon SimpleDB web service to create a student in Amazon SimpleDB database, update the student, list all students in the datbase, print count of students in the database, delete a student from the database.

All we are doing is CRUD operations [Create, Read, Update, Delete] with student object.

Prerequisites:

To run this you will need a Amazon SimpleDB account with Amazon Web Services.

Step 0: let us create a Entity Manager

public class SimpleDBEntityManagerFactory
{

public static EntityManager getEntityManager()
{
final EntityManagerFactoryImpl factory = new EntityManagerFactoryImpl(“studentdb”,null);
EntityManager em = factory.createEntityManager();

return em;
}

}

Create a file called simplejpa.properties and add it to your classpath.

Contents of simplejpa.properties are as below:

accessKey = sdfgsdfhsryerhsdfhsdfh
secretKey = dfsdfhsdfhsdfhsdjfsdjf
printQueries = true
sessionless = false
threads = 10
groovyBeans = false

The accessKey and secretKey above are provided by Amazon web service, when you register with them.

Step 1: Now let us create our Student Domain

EntityManager em = SimpleDBEntityManagerFactory.getEntityManager();
student.setId(String.valueOf(id));
em.persist(student);

A domain called student will be created on running the above snippet of code.

Domain is same as a table in relational database with columns.

Each row in a domain is called item.

Each item will have attributes.

Each attribute will have a name and value.

Continue Reading ….

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Posted on 04 March 2009 by Srinivas Nelakuditi

Amazon SimpleDB Web Service with Typica API and Java

aws logoIn this article I will explain how to use Amazon SimpleDB web service from a Java application.

I am going to create a student object. After creating the student object, we will use Amazon SimpleDB web service to create a student in Amazon SimpleDB database, update the student, list all students in the datbase, print count of students in the database, delete a student from the database.

All we are doing is CRUD operations [Create, Read, Update, Delete] with student object.

Prerequisites:

To test this you will need a Amazon SimpleDB account with Amazon Web Services.

Step 0: let us create a database in Amazon SimpleDB

com.xerox.amazonws.sdb.SimpleDB studentDB = new SimpleDB(key,password);

The key and password above are provided by Amazon web service, when you register with them.

Step 1: Now let us create our Student Domain

studentDB.createDomain(“student”);

Domain is same as a table in relational database with columns.

Each row in a domain is called item.

Each item will have attributes.

Each attribute will have a name and value.

Continue Reading ….

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Posted on 03 February 2009 by Srinivas Nelakuditi

Core Java

Core Java Page

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Posted on 02 February 2009 by Srinivas Nelakuditi

Java origins & history

Java Logo

Java Logo

1991
The Green Project begins looking for a purpose. They discuss what they do and don’t like d about various technologies. They take apart many electronic devices, like cable TV set-top boxes and remote controls to find a way for the appliances to talk to each other. They discover that the consumer electronic devices like VCRs and settop boxes all have different CPUs and limited memory.
April, 1991
The Green Project (Naughton, Gosling and Sheridan) settles on smart consumer electronics as the delivery platform. Gosling starts development of a new programming language called Oak, named for the tree outside his window. Loosely based on Objective C, the language was cut to a bare minimum to be able to fit in the limited space in consumer electronic devices. Furthermore, it was explicitly not tied to any particular CPU.
August, 1991
Oak is running its first programs.
Winter, 1991
Gosling and Naughton go skiing at Joy’s place in Aspen and demo the system to him.
October, 1992
“*7″, a cross between a PDA and a remote control, is ready. This is demoed to Scott McNealy who is blown away. Following that demo, the Green Project is set up as First Person Inc., a wholly owned Sun subsidiary.
Early 1993
The Green Project hears about a Time-Warner request for proposal for a settop box operating system. First Person quickly shifts focus from smart consumer electronics (which is proving to be more hype than reality) to the settop box OS market, and place a bid with Time-Warner. They lose the bid.
Summer 1993
NCSA releases the first version of Mosaic.
Early 1994
First Person concludes that like smart consumer electronics settop boxes were more hype than reality. Without a market to be seen First Person is rolled back into Sun.However around this time someone realizes that the requirements for smart consumer electronics and settop box software (small, platform independent secure reliable code) are the same requirements for the nascent Web. For a third time the project is redirected, this time at the Web. Patrick Naughton writes a prototype browser called WebRunner in one weekend of inspired hacking.
Early 1995
Gosling gives first public talk about Oak at a conference.
May, 1995
First alpha version of Java released to the general public.
Java Duke

Java Duke

Continue Reading ….

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