java-design-patterns/marker

layout, title, folder, permalink, categories, tags

layout	title	folder	permalink	categories	tags
pattern	Marker Interface	marker	/patterns/marker/	Design	Java Difficulty-Beginner

Intent

Using empy interfaces as markers to distinguish special treated objects.

Applicability

Use the Marker Interface pattern when

• you want to identify the special objects from normal objects
• define a type that is implemented by instances of the marked class, marker annotations can not do that

Real world examples

• javase.7.docs.api.java.io.Serializable
• javase.7.docs.api.java.lang.Cloneable

Credits

• Effective Java 2nd Edition by Joshua Bloch