java application not working with java9 and eclipse

Question

I am trying to create a HelloWorld module of Java9 following steps were given below.

1. File>New>Java Project

2. Right-click project(i.e. com.hello)>New>Source Folder>enter source folder name(.e. com.hello)

3. Right click Source Folder(i.e. com.hello)>New>Package>enter name(same as source folder name i.e com.hello)

4. Right click Source Folder(i.e. com.hello)>New>File>enter file name(java9 standard file name for module which is module-info.java)

   module com.hello {
           exports com.hello;
   }
   

5. Right Click Package(i.e com.hello)>New>enter class name(i.e. HelloWorld)

   package com.hello;
   
   public class HelloWorld {
   
           public static void main(String[] args) {
                   System.out.println("Hello World");
           }
   
   }
   

Right click on HelloWorld>Run As>Java Application It throws

Error occurred during initialization of boot layer

java.lang.module.FindException: Module com.hello not found

My project directory structure

PS: after trying this solution my project structure looks like below

Notice: I have noticed one more thing. Afte saving the changes. eclipse(oxygen) throws

Errors occurred during the build. Errors running builder 'Java Builder' on project 'com.hello'. Unknown constant pool type 19

Answer 1

Assuming, that you are using Eclipse Oxygen.1a (4.7.1a) Release released on October 11, 2017 to support JPMS and Junit5 you can adapt to the following -

While you are creating a new Java project, you need to make sure your com.hello package and module-info.java is under the src folder of the project. You can move them in your project to follow the complete tree that shall look like:-

com.hello[project]
|
|-src
|  |
|  |-- com.hello[package]
|  |   |
|  |   |- HelloWorld.java [your class]
|  | 
|  |--module-info.java

Note:- In case you are attempting to create a project based on Maven(pom.xml visible in your structure), you might want to follow answers to Maven in Eclipse: step by step installation.