java9-modularity-basic

The main goal of this project is to explore basic features of modularity introduced in Java 9:

• exports
• exports X to Y
• requires
• requires transitive
• open module

Reference: Java 9 Modularity

project structure

• moduleA, moduleB, moduleC - exploring exports, exports X to Y, requires, requires transitive.

• openModule, ordinaryModule, reflection - exporing open module and correlate modularity with reflection.

project description

Assume that we analyze module-info.java under module X

• exports Y - exporting package Y.
• exports Y to Z (Qualified Export) - export package Y to module Z.
  In general, we should avoid using qualified exports between modules in an application.
• requires Y - indicates a dependency on the module Y.
  Remember that the module Y has to be also added to dependencies of X (directly to module path or to pom.xml).
• requires transitive Y - requiring automatically all modules required by Y.
• open module - all its types are available for deep reflection (break into private parts of types at run-time) by other modules, while strong encapsulation is still upheld at compile-time. This property holds regardless of whether any packages are exported.
  Deep reflection is used by many libraries. For example, Spring or Hibernate inject values into nonpublic fields of classes.

project content