Spring 5 integrates with JDK 9 modularity primarily through its support for the Java Platform Module System (JPMS), which was introduced in Java 9. This integration allows developers to use Spring 5 in applications that are structured as modules, leveraging the modularity features of JDK 9 for better application scalability, maintainability, and performance.
Key Aspects of Spring 5's Integration with JDK 9 Modularity
Module Compatibility:
Spring 5 is compatible with JDK 9's module system. This means that Spring 5 can run on both the classpath and the modulepath of Java 9. This dual compatibility is crucial for easing the transition for applications from older versions of Java to Java 9[2].
Automatic Modules:
Spring Framework 5 jars come with "Automatic-Module-Name" manifest entries. These entries define stable language-level module names (like spring.context, spring.core, etc.) which are independent of the jar artifact names. This feature allows Spring Framework jars to be used as automatic modules in a Java 9 modular application, even though they are not explicitly modularized[5].
Adoption of JDK 9 Features:
Spring 5 utilizes several JDK 9 features to enhance its functionality and performance. For example, it uses the @Deprecated annotation improvements in JDK 9 for better deprecation documentation. Additionally, internal code improvements leverage JDK 9's enhanced reflection capabilities for more efficient operations[2][3].
Support for Reactive Programming:
While not exclusive to JDK 9, Spring 5's support for reactive programming fits well with the modular and asynchronous programming models that are often used in conjunction with JDK 9. Spring 5 includes a new module, spring-webflux, which supports reactive programming on the web layer, aligning with the non-blocking and reactive features of JDK 9[2].
Practical Implementation
To practically implement a Spring 5 application using JDK 9 modularity, developers need to define module descriptors (module-info.java) for their application modules. These descriptors should specify dependencies on Spring modules and other required modules. For in...
