How to install Java

 

To run the java file, you need to download the JDK (Java Development Kit). JDK is software which is used to compile and run the Java program.

You need to download the JDK latest version which will be consisting of the compiler and a JVM (Java Virtual Machine).

The compiler will help the Java program to convert into machine understandable codes also known as the byte codes. After the process of compilation will be finished, the byte codes will be run in the machine through JVM.

So without JDK you won’t be able to run and execute java programming language.

 

Which JDK version to be installed for Mac and Windows:   

Since JDK has different versions, so you might get confused which version is compatible with your pc/mac.

You should always download the long term support version of JDK. If you download the short term support version, then the support will be for a limited period, may be 6 months or so.

JDK version 8 and version 11 are the long term support version of JDK. Mac operating system is best compatible with JDK version 11.

Since windows system is divided into 32-bit and 64-bit operating system, hence this might be tricky for you to choose the right version of JDK.

For 32-bit operating system, you need to install JDK version 8 and for 64-bit operating system, you need to download JDK version 11.

To check whether your pc is 32-bit or 64-bit operating system, do right click on my computer and go to properties. In properties window, you will find your system type.

 How to download JDK:

Go to your computer browser and type JDK download.

Click on the first link (www.oracle.com)

Now you will be landed on the Java standard edition download page.

Since we are using Windows 64-bit operating system, we are downloading JDK version 11. You can download the required version of JDK as per your system requirement.

Just click on the JDK download link and your downloading will start immediately.

 

Note: You have to create an oracle account in order to download the JDK. Without an account, you won’t be allowed to download the JDK. The account opening process is very simple. You just have to fill the basic information in the form and your account will be activated immediately. You will also get a verification email in your given email id.

 

After the download process will be finished, you have to install the JDK in your system. The installation process is very simple. You just have to follow the step by step instructions and your Java will be installed easily.

To install Java in your machine, just double click on the JDK.

 

Now just follow the instructions. In few steps you will get Java installed in your computer.

You just have to keep the settings as default and click on the next button.

In order to check whether Java has successfully been installed in your computer, just open the command prompt and type the bellow command.

java -version

As soon as you type the above command and hit the enter button, it will immediately show you the Java version installed in your machine.

Sometimes, your computer may not find the JDK file location even after a successfully JDK installation. In that case you have to tell your computer the exact location of JDK file.

Otherwise the command prompt might show error as your computer could not identify the exact JDK location.

Don’t worry. You can easily fix this issue.

Just trace the path to the bin folder inside the JDK. The JDK is normally installed inside the C drive of your computer.

Now copy the path and paste it to the environment variable. Once you paste the path to the environment variable, your machine will get to know where the JDK has been installed in your machine.

How to find the environment variable in your computer:

Go to the properties of your computer.

 Then click on the advanced system settings.

Click on the Environment variables button.

Now edit the value of path variable under the system variables section.

You have to paste the path in the variable value field and click on ok button.

That’s it. Now the environment variable has been set which will let your computer know the exact location of JDK.

Go ahead and type the same command in the command prompt and the command prompt will surely return the java version of your computer this time.

 

How to run your first Java code:

After installing JDK, your computer is fully capable to compile and run a Java program now.

Let’s see how we can write our very first Java program and execute the same.

 

Step 1:

Open your notepad and type the below java program.

You have to save the file in the same name as mentioned in the public class with a .java extension.

If you are not being able to understand the codes written above, you don’t have to be worried at all.

We are going to discussion everything in detail in our other future lessons.

Now open your command prompt and go to the location where you have saved your notepad file.

In our case, we have saved our notepad file in desktop, so we go to desktop.

In command prompt write javac Filename.java (filename with extension) and press enter. This will allow the compiler to compile the java codes into machine readable byte codes.

Note: After compilation, you will notice there is another file with .class extension at the same location where your .java file was saved. This file contains byte codes.

Then you have to pass java Filename (filename without extension) command and this will show you the message inside the java program.

Congratulations! You have successfully compiled and run your first java program.

You could observe the entire compilation and execution of the program took place without the help of any IDE (Integrated development environment).

 

Installing IDE for Java programming:

As you have noticed, we did not use any IDE to execute our first java program.

IDE stands for an integrated developing environment where you get most advanced features which are going to help you a lot and make your programming experience smooth and enjoyable.

We are using here Eclipse IDE to compile and run our Java program.

 

How to download Eclipse IDE:

Go to Google.com and search for Eclipse IDE download.

Open the first website (www.eclipse.org). 

Click on the download button. As soon as you click on download button, your download will automatically start.

After downloading completes, install the IDE. The installation process is very simple. You just have to follow the instructions and thereby your IDE will be ready to use.

 

How to run Java program in Eclipse IDE:

It’s very easy to run a Java program in Eclipse IDE.

Unlike a notepad, your Eclipse IDE will automatically show you any probable error if occurs during the coding process.

The IDE also shows the programming codes in different colors that help the coder understand their codes better.

It provides auto-complete feature for coding and also one-click compilation and program executive feature.

After you have successfully installed your Eclipse IDE, launch the IDE.

In order to write your first Java program, click on Create a Java project.

Write a project name and click on Finish button.

Have a look at the project explorer now.

There are 2 folders automatically created under your given project name.

Right click on the src folder go to New and click on Class.

Now give a package name and class name.

Also make sure that the “public static void main(String[] args)”  method stub is checked.

And finally click on the Finish button.

Now you will see, a .java file has already been created and lot of program codes have already been written by the IDE.

To print Hello World in the console, add the below codes and click on the RUN button.

          System.out.println("Hello World !");

As soon as you click on the run button, your program will be compiled and executed.

You will also be able to see the Hello World message in the console.  

                                               

Congratulations! You have successfully been able to run your first Java program in Eclipse IDE.