package com.hello.docker;

public class HelloDocker {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		System.out.println("Hello, docker");

	}

}

package com.hello.docker;

public class HelloDocker {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		System.out.println("Hello, docker");
		System.out.println("This is an example");

	}

}

Update HelloDocker.java