Here, the journey ends for Dependency Injection in Java 9. Let's summarize what we learned from this chapter. Firstly, we learned key features introduced in Java 9, such as Java Platform Module System, JShell, JLink tool, multi-release of JAR, Enhanced Stream API, Stack-Walking PI, Immutable collection methods, and HTTP 2.0.

Secondly, in Modular Frameworks in Java 9 section,  we learned the meaning of modularity and the need of modular design in Java applications. We also learned how JPMS changes the earlier JDK into Modular JDK in detail.

After that we learned about an important element of modular systems, which is modules. We saw how module structure is defined with the help of different module descriptors and module types.

And lastly, we learned how to write simple modules using commands to understand how Dependency Injection works in Java 9 between modules.

In the next chapter, we will discuss concepts of Dependency Injection in Spring Framework in detail.