The Java Module System (Project Jigsaw), introduced in Java 9, enables applications to be organized into well-defined modules with explicit dependencies and strong encapsulation. For large-scale enterprise applications, it improves code organization, maintainability, security, and deployment efficiency by breaking monolithic systems into smaller, manageable units.
Key Points: • Modules explicitly declare dependencies using module-info.java, making application architecture clearer and easier to maintain. • Strong encapsulation hides internal implementation details and exposes only the required APIs, improving security and reducing unintended access. • Applications can include only the required modules, reducing memory usage, startup time, and deployment size.
Example: In a banking application, separate modules can be created for customer management, payments, loans, and reporting. Each module exposes only its public APIs while keeping internal classes hidden, making the system easier to develop, test, and maintain.
Code Example:
module com.bank.payment {
requires com.bank.customer;
exports com.bank.payment.service;
}Interview Tip: A concise interview answer is: The Java Module System improves large-scale enterprise applications by introducing strong encapsulation, explicit dependency management, and modular architecture. It makes applications easier to maintain, more secure, and more scalable while reducing deployment size and improving overall system organization.