java-design-patterns/chain/README.md

layout, title, folder, permalink, categories, tags

layout	title	folder	permalink	categories	tags
pattern	Chain of responsibility	chain	/patterns/chain/	Behavioral	Java Gang Of Four Difficulty-Intermediate

Intent

Avoid coupling the sender of a request to its receiver by giving more than one object a chance to handle the request. Chain the receiving objects and pass the request along the chain until an object handles it.

Applicability

Use Chain of Responsibility when

• more than one object may handle a request, and the handler isn't known a priori. The handler should be ascertained automatically
• you want to issue a request to one of several objects without specifying the receiver explicitly
• the set of objects that can handle a request should be specified dynamically

Real world examples

• java.util.logging.Logger#log()
• Apache Commons Chain
• javax.servlet.Filter#doFilter()

Credits

• Design Patterns: Elements of Reusable Object-Oriented Software