How
to create, build and run a Java Hello World program with Eclipse
If you
are new to Java programming and Eclipse IDE, this step-by-step tutorial helps
you get started to be familiar with the most Java IDE by writing your first
Java program using Eclipse. And you will be able to build and run your program
inside Eclipse.
1. Download and
Install Eclipse IDE
Eclipse
is the most popular Integrated Development Environment (IDE) for developing
Java applications. It is robust, feature-rich, easy-to-use and powerful IDE
which is the #1 choice of almost Java programmers in the world. And it is
totally FREE.
As of
now (fall 2016), the latest release of Eclipse is Neon (version 4.6). Click the
following link to download Eclipse:
http://www.eclipse.org/downloads/eclipse-packages
You will
see the download page like this:
You can
install Eclipse either by downloading the Eclipse Installer or package (zip
file). I’d recommend you to download by package. Eclipse comes with various
packages for different development purposes. For Java, there are two main
packages listed as you see above:
·
Eclipse IDE for Java EE Developers: This
is for developing Java EE applications (web applications using Servlets &
JSP).
·
Eclipse IDE for Java Developers: This
is for developing Java SE applications, a subset of the Java EE Developer
package.
So I
recommend you to install the Eclipse IDE for Java EE Developers package
because sooner or later you will need to build Java web applications, although
this tutorial only shows you how to write a Java console application.
Click on
the link 32-bit or 64-bit (depending on the
bit version of your operating system) to start download the package.
You will
see the package name like this: eclipse-jee-neon-R-win32-x86_64.zip
Extract
this ZIP file into a directory on your computer. You will see a directory
called eclipse containing Eclipse’s installed files:
Eclipse
Neon requires Java 8 or newer so make sure you have JDK 8 already installed on
your computer. If not, follow
this tutorial to install JDK.
Click eclipse.exe file
(Windows) to start the IDE. You will see the splash screen of Eclipse Neon:
That’s
it! You have successfully installed Eclipse IDE. Next, let’s see how to create
a workspace.
2. Choose a Workspace
Directory
Eclipse
organizes projects by workspaces. A workspace is a group of related projects
and it is actually a directory on your computer. That’s why when you start
Eclipse, it asks to choose a workspace location like this:
By
default, Eclipse created a workspace directory at your USER_HOME\workspace. If you want to choose another directory, click Browse. Here I chose a different workspace:
Check Use
this as the default and do not ask again if you don’t want to be asked
whenever you start Eclipse. You can always change workspace when Eclipse is
running.
Click OK.
You should see the welcome screen:
Now, we
are ready to create a Java project.
3. Change Perspective
Before
creating a new Java project, let familiarize yourself with Perspective.
Imagine a perspective is a predefined configuration specialized for a specific
aspect of development process such as Java, Java EE, Debug, Database
Development, Web, etc. Depending on your need, you can switch
back and forth among different perspectives during a development session.
Since we
installed Eclipse IDE for Java EE Developers, the default perspective is Java
EE. To change perspective, go to Window > Perspective > Open
Perspective > Other… You will see a small dialog listing all
available perspectives:
Here we
choose Java perspective. Click OK. Here’s how the Java perspective would look like:
4. Create a Java
Project
To
create a new Java project in Eclipse, go to File > New > Java
Project. The New Java Project wizard dialog appears let
you specify configurations for the project:
Enter
project name: HelloWorld. Leave the rest as it is, and click Finish.
You
should see the HelloWorld project is created in the Package Explorer view as
following:
It’s
recommended to create a package for your project. Right click on the project,
and select New > Package from the context menu:
In the New Java Package dialog, enter the name your package. Here I
enter net.codejava:
Now, it’s
time to create a Java class for your hello world application.
5. Write Your First
Java Program
To
create a new Java class under a specified package, right click on the package
and select New > Class from the context menu:
The New Java Class dialog appears, type the name of class as HelloWorld and choose the option to generate the main() method:
And click Finish. The HelloWorld class is generated like this:
Now, type
some code in the main() method to print the message “Hello World” to the console:
That’s it.
We have created a Java hello world program using Eclipse IDE.
6. Compile, Build and
Run Your First Java Program
By
default, Eclipse compiles the code automatically as you type. And it will
report compile errors in the Problems view at the bottom like
this:
If you
want to disable automatically build feature, click the menu Project and uncheck Build Automatically:
However,
it’s strongly recommended to keep the auto build mode for it helps you detect
errors instantly.
Now,
let’s run the hello world application. Click menu Run > Run (or
press Ctrl + F11), Eclipse will execute the application and show
the output in the Console view:
That’s
it! The HelloWorld program has run and printed the output “Hello World”
and terminates.
We hope
this tutorial help you get started with Eclipse and Java easily. Thank you for
reading.
References