DockerFile to run a java program

Question

Hi I\'m new to Docker and trying out to write a new image from the scratch. I am writing this dockerFile to compile and run a simple java program available in the same directory

Answer 1

Try to follow this, i have mentioned all the steps to be followed below.

Step 1. Create a java file HelloWorld.java

public class HelloWorld {

  public static void main(String[] args){

    System.out.println("Hello World! ");

  }

Step 1.1 Generate class file Ex: javac HelloWorld.java

Step 2. Create manifest.txt file

Manifest-Version: 1.0
Main-Class: HelloWorld

Step 3. Create jar file Ex: jar cfm HelloWorld.jar manifest.txt HelloWorld.class

Step 4. Create a file with name Dockerfile (no extension)

FROM java:7

WORKDIR /

ADD HelloWorld.jar HelloWorld.jar

EXPOSE 8080

CMD java -jar HelloWorld.jar

Step 5. Come out of the current directory For exampe: From C:/custom-docker/java-docker to C:/custom-docker and run this cmd docker build -t java-docker (use the folder name, here java-docker)

Note: Run the command prompt as administrator for windows or prefix sudo in all commands for linux

Step 6. Skipping (push and pull) - Optional

Step 7. Run this cmd docker images and find the latest Image ID

Example:

REPOSITORY | TAG | IMAGE ID | CREATED SIZE < none > | < none > | 58df7fdecdeb | 3 minutes ago

Step 8. Finally run this cmd docker run 58df7fdecdeb, and you could see output as

"Hello World"

PS. Thanks Julia Bondarchuk

-- Happy coding :)