.java files into .class files turn the jar package

1. Run javac 

2. Write a test HelloWorld HelloWorld.java

public class HelloWorld {
    public static void main(String []args) {
        System.out.println("Hello World");
    }
}

 

3. The packaged into .class .java

javac HelloWorld.java

Then generates HelloWord.class

 

4. The package .class packetizing is .jar

jar cvf HelloWorld.jar HelloWorld.class

It will generate a directory below

HelloWorld.jar jar package