## Uses of Interface
java.util.Observer

Packages that use Observer
java.util: Contains the collections framework, legacy collection classes, event model, date and time facilities, internationalization, and miscellaneous utility classes (a string tokenizer, a random-number generator, and a bit array).

### Uses of Observer in java.util

Methods in java.util with parameters of type Observer
`void` Observable.`addObserver(Observer o)` Adds an observer to the set of observers for this object, provided that it is not the same as some observer already in the set.
`void` Observable.`deleteObserver(Observer o)` Deletes an observer from the set of observers of this object.