Java Command not found
Java Command not found error is displayed if Java is not installed on the computer or if the command prompt cannot find Java.exe to run the program. Our Java software is compiled using the javac command. The javac tool is typically used to determine whether Java is currently installed on our system. When we try to run the javac command on a machine without Java installed, we receive the error javac command not found, or Java is not Recognized. This problem can also occur if Java is installed on our system, but the Path is not added to the environment variable for the system. Our command prompt displays the error message javac Command Not Found, or Path is not recognized when the compiler cannot locate the javac.exe file. You can run into the java command not found problem when attempting to launch Java code through the Java IDE or command prompt. Running Java on any platform, including Windows, Linux, or Mac, may result in this problem.
Program to display Java command not found
DisplayError.java
// Importing packages
import java. io. * ;
import java. Util. * ;
// class with name DisplayError is declared
class DisplayError
{
// Main section where execution of the program
public static void main( String s )
{
System . out. print ( " Hello " ) ;
}
}
Output

How to solve javac error if it is not installed?
1.First of all, Java or JDK must be installed on our system.
- You can access the below link to download Java JDK
- https://www.oracle.com/in/java/technologies/javase-downloads.html.
Steps to download the JDK

1. Our system must first have Java or JDK installed in order to resolve this issue. Open the link mentioned above if system does not have JDK installed. If the JDK is already present in our system, we must add the path variable to the environment variable for our system. This Path effectively points to the location of the folder containing the java.exe file. As a result, adding the bin directory is necessary since the bin folder contains the java.exe file.
Below is the Path for the bin folder
C:\ProgramFiles\Java\jdk1.8.0_05\bin;
2. We have two choices for setting the Path to the environment variable. Setting the Path temporarily is the first choice while setting the Path permanently is the second. We enter the following command at the command prompt after typing it. The Path is set to the desired place as soon as the enter key is pressed. We may then compile and run the java program after running this command. To set the Path permanently, follow the below instructions.
By selecting the Advance system settings option on our system, we can access the advanced system settings.

3. Upon clicking Environment Variables, a new dialogue box for permanently changing the Path appears. We will click the New button to set a path, showing the New User Variable box. We will name the variable Path, whose value will be the Path to the bin directory in the JDK folder. We establish a new user variable in the absence of a path variable. If it already exists, we change it and add the path value to that variable. When we click the Edit button, a new dialogue will open, and from there, we click the New button to add the Path to the bin directory and click the Ok button.

4. When they first start up, the command prompt and terminal window read environment variables. Though you did not restart PowerShell or the command prompt, you will still have a "Java not recognised" issue even if the JDK has been installed and the PATH variable has been configured correctly. Try again after restarting your terminal window or the program that needs to locate the Java command. Java not recognized error should be permanently resolved.
When building a Java application, if you encounter a "command not found" issue.
First, determine the platform you are compiling in. It is an IDE or a command prompt. Check your Java program's text file if you encounter the same command error when compiling your Java program in the command prompt.
If javac starts up, but you still receive an error, verify your program's grammar in the Java text file and the file's name (which should match the class name).
If javac does not launch, examine the file's Path or the environment's JDK path.