Creating modular source code
Now it is time to start creating the necessary directory structures, and write the code for the module-info.java files and the source Java files for each module. We will create the com.renderer.math module.
Create a directory named Renderer and a src sub-directory. We will use Renderer/src (Renderer\src in Windows) as our base directory for the source code. However, take into account that you don't need to create any folder in a case where you download the source code.
Now create the com.renderer.math directory in Renderer/src (Renderer\src in Windows). Add the following lines to a file named module-info.java in the recently created sub-folder. The next lines compose the module descriptor for a module named com.renderer.math. The code file for the sample is included in the java_9_oop_chapter_13_01/Renderer/src/com.renderer.math sub-folder, in the module-info.java file.
module com.renderer.math {
exports com.renderer.math;
}The module keyword followed by...