How to run a JAR file in Java

Question

I have created a JAR file. But I am not able to run it. How can I execute it?

Answer 1

The command given below will help you to run the JAR file.

java -classpath Predit.jar your.package.name.MainClass

We should specify a main class in the JAR file Manifest.

For Example: If you have a Demo class.

public class Demo
{
    public static void main(String[] args)
    {
        System.out.println("Hello world. Happy Learning");
    }
}

manifest.mf will be:

Manifest-version: 1.0
Main-Class: Demo

Now, you can run the code.

javac Demo.java
jar cfm test.jar manifest.mf Demo.class
java -jar demo.jar