Cross-cutting concerns are applicable to all application layers—including logging and security, among others. AOP is typically used to implement cross-cutting concerns.

Unit tests and integration tests fit this category since they are applicable to all layers.

Important Spring Modules related to cross-cutting concerns are listed as follows:

• spring-aop: Provides basic support for Aspect Oriented Programming (AOP)—with method interceptors and Pointcuts
• spring-aspects: Provides integration with AspectJ—the most popular and fully featured AOP framework
• spring-instrument: Provides basic instrumentation support
• spring-test: Provides basic support for unit testing and integration testing