Breaking encapsulation

The Java 9 platform is more secure than its predecessor versions due to, in part, the increased encapsulation that resulted from the modular reorganization. That being said, you might have a requirement to break through the modular system's encapsulation. Breaking through these access control boundaries is permitted by Java 9.

As you read earlier in this chapter, most internal APIs are strongly encapsulated. As previously suggested, you might look for replacement APIs when updating your source code. Of course, that is not always feasible. There are three additional approaches you can take--using the --add-opens option at runtime; employing the --add-exports option; and --permit-illegal-access command-line option. Let's look at each of those options.