Uses of Interface java.util.Observer (Java Platform SE 8 )
Date: 2026-04-17

## Uses of Interface
java.util.Observer

- Packages that use Observer
  Package | Description
  --- | ---
  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
    Modifier and Type | Method and Description
    --- | ---
    `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.

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