How to Compile and Run Java Program in CMD Using Notepad

When you will reach at the end of this Tutorial, You are able to:

• To download and Installation JDK

• To Setting up Java Environment for Windows PC (JAVA_HOME)

• Understand What and Why about JAVA_HOME Environment Variable.

• Create .java file using notepad.

• Write a Simple java program using notepad.

• Compile and Run Java Program using cmd.

So, let’s learn Step by Step to Run and Java Program in CMD using notepad.

Step 1: 

Download JDK (Java SE Development Kit) form given Link:

https://www.oracle.com/java/technologies/javase/javase-jdk8-downloads.html

Step 2: 

You will get jdk-16.0.1_windows-x64_bin.exe file. Now Install JDK

Step 3:  

After Installation, You have to Set Up Java path environment variable, for that

    - Go to system properties in windows 10

    - Go to Advanced System Settings, it will open the System Properties window.

    - Select Environment Variables from the properties window. It will open the Environment Variables window.

- In Environment Variable window, Under System Variables select path and click edit. This will Open Edit Environment variable window.

    - Now go to C:\  --> program Files -->Java ---> jdk-16.0.1 --> bin

    - In my case: C:\Program Files\Java\jdk-16.0.1\bin

    - Copy this path and go to Environment Variable dialogue.

    - In Edit Environment Variable  Window click new and paste the path(C:\Program Files\Java\jdk-16.0.1\bin) we have already copied.

- Click OK

Step 4: 

Setting Up JAVA_HOME PATH environment variable

    

    - Go to system properties in windows 10

    - Go to Advanced System Settings, it will open the System Properties window.

    - Select Environment Variables from the properties window. It will open Environment Variables.

    - Now go to C:\  --> program Files --> Java --> jdk-16.0.1

    - In my case: C:\Program Files\Java\jdk-16.0.1

    - Copy this path and go to Environment Variable dialogue.

    - In the Environment Variable window, Under System Variables click new. It will open the New System Variable window. 

    - In New System Variable, write variable name : JAVA_HOME

    - In variable value name type: C:\Program Files\Java\jdk-16.0.1

    - Click OK, 

Before moving next steps, Let’s Understand the importance of the Environment variable.

What is JAVA_HOME?

    JAVA_HOME is the name of an environment variable on the operating system that points to the installation directory of JDK (Java Development Kit) 

    - Example: JAVA_HOME = C:\Program Files\Java\jdk-16.0.1

 

Why is JAVA_HOME needed?

    To create and compile Java applications/programs, you need to set up the PATH environment variable of the operating system. So development tools like Eclipse, NetBeans can be executed. If the PATH environment variable doesn’t contain a path to JDK, a Java-based program will give some error. 

    For example, typing java in the command prompt showing this error:

'java' is not recognized as an internal or external command, operable program, or batch file. Or Eclipse may prompt Error: Eclipse launch error no Java home found

Step 5: 

Now, We need to Check Java JDK is installed properly or not using CMD.

    - Go to run command using windows key + r

    - Type cmd

    - Now type java -version

    - It will display the version name 

    - Now You are ready to run your first java program.

Step 6: 

Open Notepad and create file with .java extension.

In our example, I have created hello.java file. ( The first letter of Filename Should be in capital form)

-          Open Notepad

-          Go to File à Save as

-          It will Open Save as Window

-          Now In Save as window type filename Hello.java and in save as type Select “All Files”.

-          Click On the Save Button.

Step 7: 

Now write and save given simple java program.

public class hello{

public static void main(String args[])

        {

                System.out.println("Welcome to Java learning with COmputer Bits");

                }

}

Note: The first letter of Class name and file name should be in capital form and both are equal.

Watch Tutorial Video on How to run Java program using cmd:

Step 8: 

Now we are Ready with hello.java file

Step 9: 

We have to open CMD with current working directory, where our hello.java file is.
   

- To open CMD: 

press  Windows key + r to open RUN and then type cmd and press Ok.

- It will Open CMD.

- You need to get into current working directory using CD command.

-  To open CMD with Current Working Directory:

o   Simply open the folder where our hello.java file is.

o   Then in the address bar type cmd.

o   It will Open cmd in the current working directory.

- Check out the below image for a better understanding:

-  Now type javac hello.java to compile it. It will generate byte code file with .class extension.

-  In our example hello.class file will generate.

-  Now, To Run java program write java hello in cmd

-  If there is not any error then, we will get output.

-  That’s IT. Now you know how to set up, create and run java program.

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