Click here to close now.

Welcome!

AJAX & REA Authors: Dana Gardner, VictorOps Blog, Liz McMillan, Elizabeth White, Ken Fogel

Related Topics: Java, AJAX & REA

Java: Article

Learn Java in 10 Minutes

Basic Java Tutorial

What is Java?
You can find tons of definition about Java on web; my answer is simple “Programming Language to develop any kind of application with Object Oriented approach and it can run anywhere”.

Sample application
For example, you need to develop an application to track your daily expenses on your PC. The application can be developed by Java by the following manner.

Minute 1 Session
First download and install Java Development Kit (JDK) from official Oracle site. The JDK is the software environment where you can compile and run your Java programs.  Download here.

Minute 2 Session
Know the commands to compile and run a Java program.  Before that you need to set the path to point your Java compiler on your development location. Assume that you have installed JDK on your C:\Program Files\Java\jdk1.7.0 drive. You need to run the following line of code in your command prompt before accessing Java compiler.
SET PATH = C:\Program Files\Java\jdk1.7.0\bin;
Open start menu and type cmd on your Windows machine to open command window.  Now open your folder where your Java programs are saved.

For example: D:/MyJava.
Cd  D:/MyJava
D:MyJava > SET PATH = C:\Program Files\Java\jdk1.7.0\bin;


Note that “jdk1.7.0\bin” folder contains Java compiler (javac) and Java interpreter (java) applications.
Now you are ready to run a sample Java program on your machine. Unlike like regular hello world application, we are going to run a practical program to track daily expenses.

Minute 3 Session
Just learn about simple Java program and know the basic steps to compile and run a program.
A Java class is a blueprint of an object. An object in an instance of a class.

Step1: Identify Java classes
Step2: Develop Java classes
Step3: Develop main class
Step4: Compile all classes
Step5: Run main class

Main class is a Java class which has interpreter calling method named main like below:

public void main(String args[]){ // main method to run a Java program
// Code to call other objects/classes
}


Minute 4 Session
In our case, we need to develop an application for daily expense tracking. The following classes may satisfy these requirements.
ExpenseTracker
ExpenseTrackerMain


Minute 5 Session
Develop ExpenseTracker Java class.

public class ExpenseTracker {

public void addExpense(String expenditure, double amount){
System.out.print(“Expenditure ”+ expenditure+”  “+amount+” added on ”+new java.util.Date());
}

}


Save this file as ExpenseTracker.java in your working folder.


Minute 6 Session
Develop ExpenseTrackerMain class to run this application.

public class ExpenseTrackerMain {

public static void main(String as[]){
ExpenseTracker tracker = new ExpenseTracker();
String expen = JOptionPane.showInputDialog(null, “Expenditure”);
String amount = JOptionPane.showInputDialog(null, “Amount”);
Double doubleAmount = Double.parseDouble(amount);
tracker.addExpense(expen, doubleAmount);
}

}

Minute 7 Session
Compile your application.  Just open your working directory where you saved these .java files and follow the below steps.
Open command prompt and go to your working directory.

Type SET PATH = C:\Program Files\Java\jdk1.7.0\bin; // recall Minute 2 session
Type javac *.java
This command will compile both ExpenseTracker and ExpenseTrackerMain Java files. This action will generate .class files inside your working directory.

Minute 8 Session
Run your application.
Open command prompt and go to your working directory.
Just type java ExpenseTrackerMain in your command window.

Minute 9 Session
Your first Java program is done.
What is next?
Just add some methods in ExpenseTracker Java file, call those methods in ExpenseTrackerMain class, compile and run again.

Minute 10 Session
Similar to Expense Tracker application develop Task Tracker application by using the following code snippet.

public void addTask(String task, Status status){
System.out.print(“Task ”+ task +”   added on ”+new java.util.Date()+”.  Status of this task is :”+status);
}


What is next?
One of the best ways to develop your Java knowledge is by Oracle’s Java Certification program. There are numerous vendors available to teach Java in the world but there are few vendors are having good knowledge and latest updates.

You can find best Java Certification Training Labs from EPractize Labs,  leading Java Certification Preparation website for all Oracle’s certifications including latest Java 7 and Java EE 6 OCE certifications.

The following Training Labs teach beginner to expert level in Java 7 programming.
1Z0-803 - Oracle Certified Associate, Java SE 7 Programmer  -  Java SE 7 OCA Training Lab
1Z1-804 - Oracle Certified Professional, Java SE 7 Programmer - Java EE 7 OCP Online Training

More Stories By Kenrick Freemen

Kenrick Freemen is a software architect doing consulting for banking and education domains. He has more than 6 years of experience in developing Java EE applications. He is a Sun Certified Java Programmer, Oracle Certified Professional, Java EE 5 Web Services Developer and Sun Certified Java EE Architect.

@CloudExpo Stories
VictorOps is making on-call suck less with the only collaborative alert management platform on the market. With easy on-call scheduling management, a real-time incident timeline that gives you contextual relevance around your alerts and powerful reporting features that make post-mortems more effective, VictorOps helps your IT/DevOps team solve problems faster.
SYS-CON Events announced today that GENBAND, a leading developer of real time communications software solutions, has been named “Silver Sponsor” of SYS-CON's WebRTC Summit, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. The GENBAND team will be on hand to demonstrate their newest product, Kandy. Kandy is a communications Platform-as-a-Service (PaaS) that enables companies to seamlessly integrate more human communications into their Web and mobile applicatio...
Roberto Medrano, Executive Vice President at SOA Software, had reached 30,000 page views on his home page - http://RobertoMedrano.SYS-CON.com/ - on the SYS-CON family of online magazines, which includes Cloud Computing Journal, Internet of Things Journal, Big Data Journal, and SOA World Magazine. He is a recognized executive in the information technology fields of SOA, internet security, governance, and compliance. He has extensive experience with both start-ups and large companies, having been ...
Skeuomorphism usually means retaining existing design cues in something new that doesn’t actually need them. However, the concept of skeuomorphism can be thought of as relating more broadly to applying existing patterns to new technologies that, in fact, cry out for new approaches. In his session at DevOps Summit, Gordon Haff, Senior Cloud Strategy Marketing and Evangelism Manager at Red Hat, will discuss why containers should be paired with new architectural practices such as microservices ra...
Companies today struggle to manage the types and volume of data their customers and employees generate and use every day. With billions of requests daily, operational consistency can be elusive. In his session at Big Data Expo, Dave McCrory, CTO at Basho Technologies, will explore how a distributed systems solution, such as NoSQL, can give organizations the consistency and availability necessary to succeed with on-demand data, offering high availability at massive scale.
From telemedicine to smart cars, digital homes and industrial monitoring, the explosive growth of IoT has created exciting new business opportunities for real time calls and messaging. In his session at @ThingsExpo, Ivelin Ivanov, CEO and Co-Founder of Telestax, shared some of the new revenue sources that IoT created for Restcomm – the open source telephony platform from Telestax. Ivelin Ivanov is a technology entrepreneur who founded Mobicents, an Open Source VoIP Platform, to help create, de...
The industrial software market has treated data with the mentality of “collect everything now, worry about how to use it later.” We now find ourselves buried in data, with the pervasive connectivity of the (Industrial) Internet of Things only piling on more numbers. There’s too much data and not enough information. In his session at @ThingsExpo, Bob Gates, Global Marketing Director, GE’s Intelligent Platforms business, to discuss how realizing the power of IoT, software developers are now focu...
Security can create serious friction for DevOps processes. We've come up with an approach to alleviate the friction and provide security value to DevOps teams. In her session at DevOps Summit, Shannon Lietz, Senior Manager of DevSecOps at Intuit, will discuss how DevSecOps got started and how it has evolved. Shannon Lietz has over two decades of experience pursuing next generation security solutions. She is currently the DevSecOps Leader for Intuit where she is responsible for setting and driv...
Operational Hadoop and the Lambda Architecture for Streaming Data Apache Hadoop is emerging as a distributed platform for handling large and fast incoming streams of data. Predictive maintenance, supply chain optimization, and Internet-of-Things analysis are examples where Hadoop provides the scalable storage, processing, and analytics platform to gain meaningful insights from granular data that is typically only valuable from a large-scale, aggregate view. One architecture useful for capturing...
SYS-CON Events announced today that Vitria Technology, Inc. will exhibit at SYS-CON’s @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Vitria will showcase the company’s new IoT Analytics Platform through live demonstrations at booth #330. Vitria’s IoT Analytics Platform, fully integrated and powered by an operational intelligence engine, enables customers to rapidly build and operationalize advanced analytics to deliver timely business outcomes ...
Thanks to Docker, it becomes very easy to leverage containers to build, ship, and run any Linux application on any kind of infrastructure. Docker is particularly helpful for microservice architectures because their successful implementation relies on a fast, efficient deployment mechanism – which is precisely one of the features of Docker. Microservice architectures are therefore becoming more popular, and are increasingly seen as an interesting option even for smaller projects, instead of bein...
DevOps is about increasing efficiency, but nothing is more inefficient than building the same application twice. However, this is a routine occurrence with enterprise applications that need both a rich desktop web interface and strong mobile support. With recent technological advances from Isomorphic Software and others, it is now feasible to create a rich desktop and tuned mobile experience with a single codebase, without compromising performance or usability.
SYS-CON Events announced today Arista Networks will exhibit at SYS-CON's DevOps Summit 2015 New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Arista Networks was founded to deliver software-driven cloud networking solutions for large data center and computing environments. Arista’s award-winning 10/40/100GbE switches redefine scalability, robustness, and price-performance, with over 3,000 customers and more than three million cloud networking ports depl...
The speed of software changes in growing and large scale rapid-paced DevOps environments presents a challenge for continuous testing. Many organizations struggle to get this right. Practices that work for small scale continuous testing may not be sufficient as the requirements grow. In his session at DevOps Summit, Marc Hornbeek, Sr. Solutions Architect of DevOps continuous test solutions at Spirent Communications, will explain the best practices of continuous testing at high scale, which is r...
Software is eating the world. Companies that were not previously in the technology space now find themselves competing with Google and Amazon on speed of innovation. As the innovation cycle accelerates, companies must embrace rapid and constant change to both applications and their infrastructure, and find a way to deliver speed and agility of development without sacrificing reliability or efficiency of operations. In her Day 2 Keynote DevOps Summit, Victoria Livschitz, CEO of Qubell, discussed...
NaviSite, Inc., a Time Warner Cable company, has opened a new enterprise-class data center located in Santa Clara, California. The new data center will enable NaviSite to meet growing demands for its enterprise-class Cloud and Managed Services from existing and new customers. This facility, which is owned by data center solution provider Digital Realty, will join NaviSite’s fabric of nine existing data centers across the U.S. and U.K., all of which are designed to provide a resilient, secure, hi...
SYS-CON Events announced today that Open Data Centers (ODC), a carrier-neutral colocation provider, will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Open Data Centers is a carrier-neutral data center operator in New Jersey and New York City offering alternative connectivity options for carriers, service providers and enterprise customers.
When it comes to the Internet of Things, hooking up will get you only so far. If you want customers to commit, you need to go beyond simply connecting products. You need to use the devices themselves to transform how you engage with every customer and how you manage the entire product lifecycle. In his session at @ThingsExpo, Sean Lorenz, Technical Product Manager for Xively at LogMeIn, will show how “product relationship management” can help you leverage your connected devices and the data th...
Thanks to Docker, it becomes very easy to leverage containers to build, ship, and run any Linux application on any kind of infrastructure. Docker is particularly helpful for microservice architectures because their successful implementation relies on a fast, efficient deployment mechanism – which is precisely one of the features of Docker. Microservice architectures are therefore becoming more popular, and are increasingly seen as an interesting option even for smaller projects, instead of bein...
Security can create serious friction for DevOps processes. We've come up with an approach to alleviate the friction and provide security value to DevOps teams. In her session at DevOps Summit, Shannon Lietz, Senior Manager of DevSecOps at Intuit, will discuss how DevSecOps got started and how it has evolved. Shannon Lietz has over two decades of experience pursuing next generation security solutions. She is currently the DevSecOps Leader for Intuit where she is responsible for setting and driv...