java.md

Compile a java file

javac -cp src_folder src/SourceFileWEntrypoint.java

or better javac -sourcepath src -d classes src/SourceFileWEntrypoint.java

Run a compiled class file

java -cp location_of_classfiles MainClassFileName

Important: Do not add the .class extension for MainClassFileName!

Build a .jar file

First compile your project to a predefined output directory

javac -sourcepath src -d out src/SourceFileWEntrypoint.java

Enter the output dir

cd out

Create a file Manifest.txt containting

Main-Class: SourceFileWEntrypoint

In that very directory (important!) run

jar cvmf Manifest.txt Jarname.jar SourceFileWEntrypoint.class *

If the code needs any resources they also need to be in out, and be referenced correctly in the code

Referencing resources within a .jar file in java code

In the folder which holds all the files to be zipped to a .jar, make sure that your resource files (e.g. images) are in the same directory as the class file needing to access these resources.

Then within an object method, to access your resource, e.g. Image.png, you call

import javax.imageio.ImageIO;

...

String imageName = "Image.png";
source = ImageIO.read(getClass().getResourceAsStream(imageName));

or, if the calling method happens to be static

source = ImageIO.read(Assets.class.getResourceAsStream(imageName));