Java 9 error: not in a module on the module source path

Question

Project structure

I have a project written in Java 8 and I want to update it to Java 9. So I separated the classes into 2 separate modules. Modules:

Answer 1

For completeness sake, the complete javac command is as follows:

javac -d out --module-source-path "./*/src/main/java/" $(find . -name "*.java")

Based on the official tutorial from OpenJDK (slightly modified directory structure shown below), and OpenJDK version "11.0.1", the above command javac works for me:

.
├── com.greetings
│   └── src
│       └── main
│           └── java
│               ├── com
│               │   └── greetings
│               │       └── Main.java
│               └── module-info.java
├── org.astro
│   └── src
│       └── main
│           └── java
│               ├── module-info.java
│               └── org
│                   └── astro
│                       └── World.java
├── out
│   ├── classes
│   │   ├── com.greetings
│   │   │   ├── com
│   │   │   │   └── greetings
│   │   │   │       └── Main.class
│   │   │   └── module-info.class
│   │   └── org.astro
│   │       ├── module-info.class
│   │       └── org
│   │           └── astro
│   │               └── World.class
│   └── lib
│       ├── com.greetings.jar
│       └── org.astro@1.0.jar